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BIOLOGY
Tuesday, 19 June 2012 12:46

BIOLOGY 1993

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

Answer all questions in this section. For each question select the most correct option and write the letter representing it in the box provided.

1.     Which one of these processes helps to lower mammalian body temperature to normal?

A.    Vasodilatation

B.     Vasoconstriction

C.     Shivering

D.    Raising of hair on the skin

2.     Six fingers in man is controlled by a sex-linked recessive gene. If a normal woman marries a six fingered man, which of the children will have six fingers?

A.    All the sons

B.     All the daughters

C.     All will be normal

D.    Half the number of girls and boys will be normal

3.     Which one of the following tissues has a protective function in plants?

A.    Xylem

B.     Phloem

C.     Cambium

D.    Epidermis

4.     What disease would you be controlling by pouring molluscicides in water?

A.    Schistosomiasis.

B.     Guinea worm infestation

C.     Typhoid

D.    Cholera

5.     Which one of the following takes place by the process of active transport in plants?

A.    Uptake of water

B.     Intake of carbon dioxide

C.     Transpiration

D.    Uptake of mineral salts

6.     In an ecosystem, the survival of all living things depends on

A.    Decomposers

B.     Primary producers

C.     Primary consumers

D.    Secondary consumers

7.     If a gecko on a wall is seen eating mosquitoes, flies, moths and grasshoppers, this animal is said to be a

A.    Parasite

B.     Symbiotic

C.     Predator

D.    Saprophyte

8.     Which one of the following structural adaptation of leaves is important for light absorption during photosynthesis?

A.    Dense network of veins

B.     Large numbers of stomata on leaf surfaces

C.     Large intercellular air spaces in the spongy layer

D.    Broad and flat shapes of leaves

9.     Which of the following is a function of progesterone?

A.    Prepare the uterine walls for importation

B.     Initiates the process of birth

C.     Initiates ovulation

D.    Initiates formation of corpus luteum.

10.  The part of the brain that controls breathing is the

A.    Cerebellum

B.     Medulla oblongata

C.     Cerebrum

D.    Hypothalamus

11.   Which of the following are respiratory surfaces in toads and frogs?

A.    The mouth, webbed toes and skin

B.     Nostrils, mouth and skin

C.     Webbed toes, lungs and mouth

D.    The mouth, lungs and skin

12. IMAGE

Figure 1 shows an experiment on photosynthesis set up by a student. The soda line was used to absorb

A.    Any oxygen given off by the plant

B.     Any carbon dioxide from the air

C.     Moisture from the air

D.    Carbon dioxide given off by the plant.

13.  Which one of the following glands produces a hormone whose normal effect is to influence the rate of heartbeat?

A.    Pituitary gland

B.     Islets of langerhans

C.     Adrenal gland

D.    Thyroid gland

14.  The condition known as oxygen debt occurs during active physical exercise in animals because of the

A.    Accumulation of carbon dioxide during physical exercise

B.     The high rate of breathing during physical exercise

C.     Accumulation of lactic acid in the body

D.    Accumulation of alcohol in the body.

15.  The root which grows from near the base of the trunk of some woody plants is called

A.    Lateral root

B.     Prop root

C.     Aerial root

D.    Adventitious root

16.  Which one of the following farming methods would cause pollution in an aquatic habitat?

A.    Mulching

B.     Crop rotation

C.     Use of fertilisers

D.    Application of farm yard manure

17.  The graph below shows changes in dry weight of a seedling of a non woody plant

IMAGE

What is the possible explanation for the shape of the curve in phase III? Rate of

A.    Respiration is constant

B.     Respiration is great than that of photosynthesis

C.     Growth is highest

D.    Assimilation is equal to respiration

18.  Which one of the blood groups will not agglutinate with any blood serum when mixed?

A.    O

B.     A

C.     AB

D.    B

19.  A male cockroach is different from the female cockroach by having

A.    Styles

B.     Circus

C.     Longer antennae

D.    Larger abdomen

20.   Which of the following conditions are necessary for producing movement in vertebrates?

(i)                Muscles must be attached to the end of bones

(ii)              Muscular bundles must occur in pairs

(iii)            One of a pair of muscles must be more strongly developed than the other

(iv)            One of a pair of muscles must consist of a smooth muscle.

A.    (i), (iii), (iv)

B.     (i) , (ii), (iii)

C.     (i), (ii), (iv)

D.    (iii), (iv).

21.  Which one of the following compounds is a consistuent of enzymes?

A.    Lipids

B.     Polysaccharides

C.     Proteins

D.    Vitamins

22.  One of two identical twins brought up differently was fatter and healthier than the other. What kinds of variation do these show?

A.    Discontinuous variation

B.     Genetic variation

C.     Social variation

D.    Habitat variation

23.  Which one of the following structures in the mammalian ear is concerned with balance?

A.    Cochlea

B.     Semi circular canals

C.     Eustachian tube

D.    Oval window

24.  The type of soil with minute air spaces and high water retention capacity is

A.    Sand

B.     Clay

C.     Sit

D.    Loam

25.  Which one of the following cannot be used in the classification of plants?

A.    Structure of the flowers.

B.     Leaf structure

C.     Type of seeds

D.    Leaf colour

26.  Figure 3 below show some fruits. Which of them are likely to be dispersed by animals?

IMAGES

A.    I and II

B.     II and III

C.     III and IV

D.    I and IV

27.  Which one of the following is not a property of a fully turgid plant cell?

A.    The vacuole has maximum volume

B.     There is no more absorption of water by the cell

C.     The cell wall resists further expansion of the vacuole

D.    The cytoplasm is only slightly separated from the cell wall.

28.  Which one of the following diets would be recommended for an overweight person?

A.    Low carbohydrate, high protein, low fat.

B.     High carbohydrate, low protein, law fat.

C.     High carbohydrate, high protein, low fat.

D.    Low carbohydrate, low protein, high fat

29.  Intestinal parasites are not digested by the host's enzymes because of

A.    Possession of attachment devices

B.     Secretion of large quantities of mucus

C.     Having a high rate of reproduction

D.    Lack of their own digestive system

30.  Which one of these is the correct order in which the following organisms occur in a food chain?

A.    Vulture, antelope, lion

B.     Lion, vulture, antelope

C.     Antelope, lion, vulture

D.    Lion, antelope, vulture

 

SECTION B

Answer all questions in this section. Answers must be written in spaces provided.

31.  The table below shows the concentrations of different substances in the glomerular filtrate and urine. Study the table and answer the questions that follow:

 

SUBSTANCE CONCENTRATIONS (%) GLOMERULA FILTRATE                URINE

Water

Proteins

Glucose

Sodium

Urea

93

0

0.1

0.3

0.003

95

0

0

0.35

2.0


 

a)     Give any one reason for the difference in the concentration of water in the glomerular filtrate and in urine.

b)    Explain the absence of proteins from both the glomerular filtrate and urine

c)     (i) which substance is reabsorbed with

-         The highest efficiency.................................................................

-         The lowest efficiency? ................................................................

(ii) Which substance is not reabsorbed at all?

d)    By what factor is urea more concentrated in urine than in the glomerular filtrate?

e)     Under what condition does glucose appear in urine?

32.  Figure 4 below shows a longitudinal section through the female reproductive system of a mammal.

IMAGE

a)     Name the parts labelled A, B, C, D and E on the diagram.

b)    State any two functions of B.

(i) ..............................................................................................

(ii) ................................................................................................

c)     In what two ways are parts A and C adapted to their functions?

A (i)..................................................................................................

(ii).....................................................................................................

C (i)..................................................................................................

(ii)....................................................................................................

d)    State any two advantages the mammalian embryo has over that of a frog during their development.

(i) ..............................................................................................

(ii) ..............................................................................................

33.  a) what do you understand by the following terms:

(i)   a habitat ......................................................................................

(ii) an ecosystem? .............................................................................

b) Use the following organisms to construct a food web showing their feeding relationship: chameleon, moth, grasshopper, herbaceous bug, praying mantis, predatory bug and plants.

c) What is the role of each of the following organisms in the food web:

(i) the plants ..........................................................................................

(ii)the grasshopper ................................................................................

(iii) The predatory bug?.........................................................................

d) Which one of the organisms listed above will have the least energy for any single food chain considered? Why?

34.  The graphs below show the effects of temperature and pH on the activity of an enzyme in the human digestive system.

IMAGE

a)     At what temperature and pH does the enzyme show optimal activity?

b)    Suggest one reason for the sharp fall in the rate of reaction of the enzyme as shown in graph A.

c)     (i) suggest the identity and location of this enzyme

(ii) Give a reason for your answer to c(i) above.

d)    For the enzyme in c(i) above, suggest the food it acts on and the end products.

Food acted on....................................................................................

End products......................................................................................


SECTION C

Answer and two questions from this section.

35.  a) What is growth?

b) Name the main parts responsible for producing growth in a shoot.

c) Describe an experiment you would perform to determine the region of most rapid elongation in the root of a bean seedling.

36.  a) What do you understand by the term 'irritability' as applied to plants and animals?

b) Explain how plants respond to light as a factor of irritability.

c) Name any three other tropic responses in plants.

37.  a) Explain how the action of muscles causes air to pass from the atmosphere into the lungs.

b) How does oxygen move from the air in the lungs into the cells of the blood?

c) Give three characteristics of an efficient respiratory organ.

38.  a) What is pollution?

b) Give an outline of the human activities, in Uganda, which may in environmental pollution.

 

 

 

Tuesday, 19 June 2012 10:45

BIOLOGY 1994

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

Answer all questions in this section. For each question select the most correct option and shade the letter representing it in the answer sheet provided.

1.     The following results were obtained from an experiment done to determine the percentage of air in a sample of soil.

Volume of water used                         = 10cm3

Volume of soil + water                        =40cm3

Volume of soil +water after stirring = 37cm3

From the results, the percentage of air in the soil is

A. 7.5

B.  8.1

C.  10

D. 23.3

2.     Which one of the following flower parts is most important in promoting insect pollination?

A. Calyx

B.  Corolla

C.  Stamens

D. Pistil

3.     Figure 1 shows an experiment which was set up and left to be observed the following day.

IMAGE

Which of the following events will have taken place?

i)    Solution 2 will have risen higher in the capillary tube

ii)  The level of solution.1 will have fallen

iii)The level of solution 2 in the capillary tube will have fallen

iv)   Concentration of solution 1 in the beaker will not have changed at all

A.    (i) and iii)

B.     (ii) and (iv)

C.     (i) and (ii)

D.    (iii) and (iv)

4.     2g of a food substance was burnt and the heat produced raised the temperature of 50cm of water from 250C to 370C. What is the energy content of the food substance in joules per gram? (Specific heat capacity of water = 4.2j per gram)

A. 1260joules

B.  2520joules

C.   300 joules

D.  105 joules

5.     Which one of the following activities takes place during the pupal stage in the life cycle of an insect?

A. Hibernation

B.  Organ formation

C.  Feeding

D. Resting

6.     A couple produced four children who were of different blood groups with the following genotypes: AO, BO, AB and OO. What were the genotypes of their parents?

A. AA and OB

B.  AO and OB

C.  BB and OB

D. AB and OO

7.     Which one of the following can be applied so as to reduce the acidity of a soil?

A. Ammonium compound

B.  Nitrate

C.  Phosphate

D. Lime

8.     The following are some characteristics of flowers.

i)    Large feathery stigma

ii)  Large brightly coloured petals Produce large quantities of pollen grains

iii)Flowers are often scented

Which of the characteristics belong to wind pollinated flowers?

A.    (i) and (ii)

B.     (iii) and (iv)

C.     (i) and (iii)

D.    (i) and (iv)

9.     The living together of a fungus and an alga as a lichen is called

A. Symbiosis

B.  Parasitism

C.  Saprophytism

D. Commensalism

10.  Which one of the following seed parts both roles of protection and nutrition during germination?

A. Endosperm

B.  Testa

C.  Coleoriza

D. Cotyledons

11.   Why is a shoot being prepared for transpiration experiments normally cut under water?

A. Avoid water loss which may cause wilting

B.  Prevent loss of sap

C.  Prevent air from entering the xylem vessels

D. Remove damaged tissue

12.  Meiotic cell division important because it ensures that

A. there is variation in the number of chromosomes

B.  the number of chromosomes of a species is not doubled at fertilisation

C.  the chromosomes of the daughter cells are identical

D. bad traits are not passed on from parents to offspring

13.  The following are features found in birds.

i)    Light bones

ii)  Webbed feet

iii)Presence of feathers

iv)    Streamlined body

which of the features are adaptations for flight?

A. (i) and (ii)

B. (ii) and (iii)

C. (iii) and (iv)

D. (i) and (iv)

14.  The following substances are secreted in mammalian sweat?

A. Urea, ammonia, water

B.  Urea, carbon dioxide, sodium chloride

C.  Urea, water, sodium chloride

D. Urea, carbon dioxide, water

15. IMAGE

Figure 2 is a simplified reflex arc. The labelled K is

A. The relay neurone

B.  A ganglion

C.  The sensory neurone

D. The motor neurone

16.  Nerves, the spinal cord and the brain make up

A.    a tissue

B.     a system

C.     an organ

D.    an organism

17.  Which one of the following shows the correct path followed by light ray to produce an image at the retina?

A.    Cornea, aqueous humour, lens, pupil, vitreous humour, retina

B.     Cornea , vitreous humour, pupil, lens, aqueous humour retina

C.     Cornea, pupil, vitreous humour, lens aqueous humour, retina

D.    Cornea, aqueous humour, pupil, lens, vitreous humour, retina

18.  Decrease in the number of mammalian red blood cells could reduce the ability of the blood to

A.    Clot

B.     Transport oxygen

C.     Destroy harmful bacteria

D.    Distribute heat.

19.  Which one of the following characters shows discontinuous variation?

A.    Blood groups

B.     Height

C.     Intelligence

D.    Skin colour in people

20.  The similarity in feeding between an amoeba and the fungus Mucor is that both

A.    Feed on dead organic matter only.

B.     Ingest undigested food materials.

C.     Digest their food within vacuoles.

D.    Secrete enzymes onto food materials from their cytoplasm.

21.  Which of the following make the skin of a toad an effective respiratory surface?

i)       Moist surface

ii)     Rough skin

iii)   Rich blood supply to the skin

iv)   Large numbers of secretory glands on the skin

A.    (i) and (iii)

B.     (i) and (ii)

C.     (ii) and (iv)

D.    (iii) and (iv)

22.  Below are some food chains: which one of them is correct?

A.    Dead wood - termite - chicken

B.     Chameleon - mantis - grasshopper

C.     Termite - hawk - snake

D.    Carnivore - plant - herbivore

23.  Which one of the following types of cells is unspecialised?

A.    Companion cell in plants

B.     Red blood cell

C.     Meristematic cell

D.    Nerve cell

24.  During inspiration the

A.    Pressure in the thoracic cavity is reduced.

B.     External intercostals muscles relax

C.     Diaphragm becomes dome shaped

D.    The thoracic cavity becomes smaller

25.  A hetozygous red flowered plant (Rr) is crossed with a homozygous white plant (rr); If R is dominant over r, what will be the phenotypes of the offspring?

A.    All red.

B.     All white

C.     Pink and white

D.    Red and white

26.  Which one of the following is a characteristic of animal cells?

A.    Presence of cell walls.

B.     Cells consist entirely of cytoplasm.

C.     Have regular shape.

D.    Have large centrally placed vacuoles

27.  Which one of the following dental formulae represents that of a ruminant (e.g. sheep)?

A. 2/2 :  1/1 :  2/2 :  3/3

B. 2/2 :  1/1 :  2/2 :  0/3

C. 0/2 :  1/1 :  2/2 :  3/3

D. 0/3 :  1/1 :  3/3 :  3/3

28.  In plants, anaerobic respiration is less efficient than aerobic respiration because during an aerobic respiration

A.    Not all the carbohydrates are broken down

B.     The amount of carbon dioxide released is less than in aerobic respiration

C.     There is less energy released per unit weight of carbohydrate broken down

D.    Less water is produced in anaerobic respiration.

29.  Which one of the following characteristics is common to birds, fish and reptiles?

A.    Regulation of body temperature

B.     Bodies are covered with scales

C.     Use of nostrils for breathing

D.    Internal fertilisation

30.  Which of the following vitamins is deficient in a person whose gums bleed?

A.    Vitamin C

B.     Vitamin E

C.     Vitamin B2

D.    Vitamin K

 

SECTION B

Answer all questions in this section. Answers must be written in the spaces provided.

31.  The table below shows the effect of wind, still air and stomata opening on the rate of transpiration of a plant in milligrams of water lost per hour per dm2. Study the table and answer the questions following.

Stomata opening (pm) 1 2 3 4 5 6 7
Wind 40 63 74 86 94 110 124
Still air 0 6 12 19 23 27 30

 

a)  (i) Compare the rates of transpiration in windy and still air conditions.

(ii) Explain your observation.

b) How does stomata opening affect transpiration rate?

c)  Name three other factors that affect the rate of transpiration.

d) State two functions of transpiration to plants.

32.  Two different sized cubes of colourless jelly A and B were used to represent models of living organisms. They were submerged in a coloured dye for a period of time and then removed and cut into half.

The diagram below show the penetration of the dye

IMAGE

a)  (i) Explain the difference between the penetrations of the coloured dye in the two cubes.

(ii) Suppose that the dye represents an essential substance being absorbed by a living organism. Explain how the problem in B could be overcome by a living organism without altering its shape.

b) Explain how the shape of a red blood cell helps it to function efficiently.

33.  a) In cattle, the gene for horned bull. Using genetic symbols show the possible genotypes and phenotypes of the F1 offspring.

Genotypes of F1 offspring

...............................................................................................................

Phenotype(s) of F1 offspring

...............................................................................................................

b)(i) a bull whose horns were removed was mated to a horned cow. Show the possible genotypes and phenotypes of the F1 offspring.

Genotypes of F1 offspring

...............................................................................................................

Phenotype of F1 offspring

...............................................................................................................

(ii) Give a reason for your answer in (b)(i) above.

34.  a) (i) Give the main difference between cold blooded (ectothermic) and warm blooded (endothermic) animals.

(ii) Give one advantage that an endothermic animal has over an ectothermic animal.

(iii) Why are ecothermic animals said to be cold blooded?

b) Give four ways in which an ectoderm reacts to the lowering of external temperature.

 

SECTION C

Answer any two questions from this section.

35.  a) (i) what are the similarity (ies) and differences between asexual and sexual reproduction in the spirogyra?

(ii) What is the advantage of asexual reproduction to such a plant?

b) Describe sexual reproduction in the spirogyra.

36.  a) Describe the digestion of proteins in the human alimentary canal.

b) What may happen to the products of digestion of proteins?

37.  Explain how a dicotyledonous leaf is adapted for the process of photosynthesis.

38.  a) Give six features which are common to adult insects.

b) (i)What is understood by the term metamorphosis?

(ii) With the aid of labelled diagrams, give an account of the life cycle of a house fly.

 

 

 

 

 


Wednesday, 06 June 2012 13:52

BIOLOGY 1995

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

Answer all questions in this section. For each question, select the most correct answer and write the letter representing it in the box provided.

1.     enzymes are said to be specific in nature because they

A.    Are proteins.

B.     Act in a particular pH medium.

C.     Act on one kind of substrate.

D.    Remain unchanged at the end of the reaction.

2.     A sample of urine from a man was boiled with Benedict's solution and the mixture turned orange in color. Which of the following is the best deduction about the condition of this man?

A.    There was a lot of glycogen in his blood.

B.     He has a deficiency of insulin in his blood.

C.     His diet has a lot of sugar.

D.    His kidneys were damaged.

3.     Which of the following will not cause an evolutionary change in an animal species?

A.    Having more males than females in the population.

B.     Abundant food supply.

C.     Presence of many predators.

D.    Severe change in environmental conditions.

4.     Which of these are characteristic of all insects?

A.    Complete metamorphosis and possession of three pairs of joined legs.

B.     Possession of three pairs of jointed legs and body divided into three main parts.

C.     Possession of one or two pairs of wings and having three pairs of joined legs.

D.    Complete metamorphosis and body divided into three main parts.

5.     In body temperature regulation, vasoconstriction

A.    Allows less blood to enter the skin capillary network.

B.     Allow less urine to be secreted into the bladder.

C.     Allows more sweat to be secreted by the sweat glands.

D.    Increases heat loss by radiation.

6.     Which type of soil has the following properties?

(i)                Heavy to cultivate.

(ii)              High water retention.

(iii)            High capillarity

A.    Sandy loam

B.     Loam

C.     Sand

D.    Clay

7.     The main function of the Eustachian tube in the mammalian ear is to

A.    Concentrate the sound waves into the middle ear

B.     Transmit sound waves to the brain

C.     Transmit sound waves to the middle ear

D.    Regulate pressure in the middle ear

8.     Which one the following results of seed dispersal may not be an advantage to a plant?

A.    Reduces overcrowding

B.     Minimizes spread of disease

C.     Stops competition for light and air

D.    Results in colonization of new areas

9.     A heterozygous red flowered plant is crossed with a homozygous white flower. If red is dominant over white, what will be the phenotypes of the offspring?

A.    ½ red and ½ white

B.     All white

C.     All red

D.    ¾ red and ¼ white.

10.  Which of the following is the best description of the term double circulation in a mammal?

A.    Blood flows into the two lungs and then into the body.

B.     Blood passes through two chambers of the heart

C.     Blood passes through the heart twice in one circulation.

D.    Blood first flows through arteries and then through veins.

11.   Which one of the following is an example of a tactic response?

A.    Rolling up of leaves on a sunny day.

B.     Withdrawal by blowfly larvae from light.

C.     Withdrawal of the hand from a hot object.

D.    Bending of a plant shoot towards light.

12.  The best method that prevents the start of gully erosion on a cultivated hill is

A.    Contour cultivation.

B.     Strip cropping

C.     Tree belts

D.    Mulching

13.  An adult person who constantly feeds on an iodine deficient diet may show one of the following conditions:

A.    Anaemia

B.     Goiter

C.     Cretinism

D.    Dry scaly skin

14.  In the flowering plants translocation of photosynthetic products is by the

A.    Xylem vessels.

B.     Scelerechyma

C.     Sieve tubes

D.    Companion cells

15.  In which part of the gut does mucus (mucin) have a protective function?

A.    Oesophagus

B.     Stomach

C.     Small intestine

D.    Rectum

16.  The main function of luteinizing hormone in the reproductive cycle of a mammal is that it

A.    Causes ovulation

B.     Causes thickening of the uterine walls

C.     Initiates the growth of a graafian follicle

D.    Maintains pregnancy for the first 3 months.

17.  During seed germination, the dry weight initially decreases because

A.    Stored food is used up for growth and respiration.

B.     Soluble food materials diffuse out of the seedlings

C.     Rate of water absorption is low

D.    Rate of cell division is low.

18.  A sample of blood from the hepatic portal vein contains.

A.    Fats

B.     Proteins

C.     High concentration of urea

D.    High concentration of products of digestion

19.  Which of the following does not affect the rate of diffusion?

A.    Density of the diffusion medium

B.     Size of diffusing particles

C.     Distance through which particles diffuse

D.    Temperature of the diffusion medium

20.  The function of amniotic fluid in foetal development is

A.    Protection of the foetus from shock

B.     Transfer of nutrients from mother to foetus

C.     Allowing gaseous exchange between mother and foetus

D.    Prevention of dangerous substances from reaching the foetus

21.  Which of the following is not a component of joints in the endoskeleton?

A.    Cartilage

B.     Tendon

C.     Ligament

D.    Synovial fluid

22.  Which one of the following structures represents the respiratory surface of a fish?

A.    Gill bars

B.     Gill rakers

C.     Gill chamber

D.    Gill filaments

23.  Meiosis normally results in

A.    Halving the number of chromosomes

B.     Production of identical cells

C.     Maintaining the number of chromosomes

D.    Propagation of new organisms.

24.  Which of these statements is not true of an ecosystem?

A.    Consumers use less food compared to what producers make.

B.     One of the ways of constructing a food chain is by observing the animals feeding.

C.     The numbers of organisms decrease from the bottom to the top of the pyramid of numbers.

D.    Because of mains feeding habits, he can be placed in any of the feeding levels.

25.  In humans, the male sex chromosomes are X and Y (XY) and the female sex chromosomes are X and X (XX). When a male gamete fuses with a female gamete the sex ratio is

A.    1: 2

B.     1:3

C.     1:1

D.    1:4

26.  Artificial immunity to a disease is developed by

A.    Catching the disease and recovering from it.

B.     Inoculation with a mild strain of the pathogen.

C.     Receiving antibiotic injections against the disease.

D.    Taking drugs that prevent the disease.

27.  Which one of the following is an example of discontinuous variation in humans?

A.    Skin color

B.     Intelligence

C.     Height

D.    Blood groups

28.  What are the final products of anaerobic respiration?

A.    Carbon dioxide, water and energy

B.     Carbon dioxide, water and alcohol

C.     Carbon dioxide, alcohol and energy

D.    Carbon dioxide and alcohol

29.  Which one the following is characteristic of monocotyledons?

A.    Leaf sheath

B.     Net venation

C.     Prominent tap root

D.    Cork layer

30.  What is the functional unit in a nervous system called?

A.    Dendrite

B.     Neuron

C.     Axon

D.    Synapse

 

SECTION B

Answer all questions in this section. Answers must be written in the spaces provided.

31.  The table below shows the effect of temperature on the activity of amylase on starch. Six test tubes, each containing a mixture of starch and amylase, were placed in water baths maintained at 00C, 100C, 200C, 300C, 400C and 500C and allowed to stand. Study the table and answer the questions that follow.

 

Test tube Temperature (0C) Time taken for starch digestion (minutes)

1

2

3

4

5

6

0

10

20

30

40

50

starch still present after 60 minutes

22

11

5

3.5

starch still present after 60 minutes


 

a)     How does temperature affect the action of amylase?

b)    Give one reason in each case for the results obtained in the tubes kept at

(i)    00C

(ii)   500C

c)     Suggest the time it would take amylase to digest starch if the temperature is kept at 00C.

d)    Describe the test you would carry out to determine the substance into which the starch has been broken.

32.  a) Give three ways of maintaining soil fertility.

b) State four ways by which soil organisms contribute to soil fertility.

c) The scheme below represents the nitrogen cycle. Study it carefully and answer the questions that follow.

IMAGE

(i)   Give the general names of the bacteria represented by letters A, B and C.

A .............................................................................................................

B .............................................................................................................

C .............................................................................................................

(ii)  Name the process labelled X and Y.

X ............................................................................................................

Y ............................................................................................................

(iii)  On the diagram show by means of arrows, the direction of the processes along the lines.

33.  a) in the study of evolution, state what is meant by

(i)     a vestigial organ,

(ii)    a fossil,

(iii)   variation

b) Give two causes of variation in an organism.

c) How has the knowledge of variation helped farmers to improve on their production?

34.  The graph below shows the results of blood cell counts taken on people living at different altitude. The counts are expressed in terms of blood cells per mm3 of blood.

GRAPH

a)     What were the red blood cell counts at

(i)    250m

(ii)   5600m?

b)    State and explain the relationship between altitude and red blood cell count.

c)     Why did the white blood cell count show no change?

d)    (i) Where in the body are red blood cells made?

(ii) How does the body deal with old blood cells?

e)     Give two ways by which white blood cells defend the body.

 

SECTION C

Answer any two questions from this section.

35.  A child sees a fierce looking dog, gets frightened and runs. Describe the sequence of events leading to the child's reaction.

36.  a) What is pollination?

b) Describe the processes that place after pollination in a flowering plant.

c) Give three differences between insect pollinated and wind pollinated flowers.

37.  a) Giving two examples in each case, explain what you understand by the terms.

b) How are parasites adapted to their mode of life?

38.  a) Why do flowering plants posses simpler excretory organs that those found in mammals?

b) Describe how the mammalian kidney forms urine?

c) What part is played by the mammalian skin in excretion?

 

Thursday, 31 May 2012 12:50

BIOLOGY 1996

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

Answer all questions in the section. For each question select the most correct option and write the letter representing it in the box provided.

1.     Individuals with blood AB are said to be universal recipients because they have

A.    No antigens.

B.     No antibodies.

C.     Both antigens and antibodies.

D.    Antibodies a and b

2.     Which one of the following is true about the nervous system of a mammal?

A.    Cell bodies of the sensory neurons are found in the ganglia.

B.     Cell bodies of the sensory neurons are found in the grey matter.

C.     Sensory neurons transmit impulses from the central nervous system to receptors.

D.    Cell bodies of sensory neurons are found in the receptors.

3.     The last segment of a caterpillar bears a pair of structures called

A.    Prologs.

B.     Ovipositors.

C.     Claspers.

D.    True legs.

4.     In cattle the gene for red coat color, R, is co-dominant to that for white coat color, W. if a red cow mated to a white bull, what would be the phenotype of the F1 generation?

A.    All red

B.     All white

C.     3 red: 1 white

D.    Intermediate coat color (roan)

5.     What are the products of the hydrolysis of lactose?

A.    Galactose and fructose.

B.     Glucose and Galactose.

C.     Glucose only

D.    Glucose and fructose.

6.     Photosynthesis is said to have a pair of raw materials, a pair of conditions, and a pair of products. Which of these is the correct set?

A.    Carbon dioxide and light; water and chlorophyll; oxygen and sugars.

B.     Water and light; carbon dioxide and chlorophyll; oxygen and sugars.

C.     Light and chlorophyll; carbon dioxide and sugar; water and oxygen.

D.    Carbon dioxide and water; light and chlorophyll; oxygen and sugars.

7.     Which one of the following controls the activities of other ductless glands?

A.    Thyroid

B.     Adrenal

C.     Pituitary

D.    Islets of langerhans

8.     A runner is a

A.    Stem which bends over and roots in the soil.

B.     Horizontal stem above the ground which gives roots and aerial shoots at the nodes.

C.     Horizontal stem beneath the ground which gives rise to roots and aerial shoots at the nodes.

D.    Short vertical stem buds beneath the soil.

9.     What would result if secretion of gastric juice were inhibited in an individual who has just had a meal of posho and beans?

A.    The person would suffer from heartburn.

B.     The person would suffer from constipation.

C.     Digestion would not take place.

D.    Digestion of certain food types would be delayed.

10.  Which of the following is true about arteries? They

A.    Carry blood away from the heart.

B.     Carry deoxygenated blood.

C.     Carry oxygenated blood.

D.    Possess valves along their length.

11.   Which of the following is true about nastic response?

A.    Depends on the direction of the stimulus.

B.     Does not involve hormones.

C.     It is relative slow.

D.    Does not involve only growth.

12.  Urine is formed by

A.    Ultra filtration and selective reabsorption.

B.     Selective reabsorption in the proximal tubule.

C.     Selective reabsorption at the loop of Henley.

D.    Ultra filtration in the Bowman's capsule.

13.  Which one of the following substances accumulates in muscles during vigorous exercise?

A.    Water

B.     Lactic acid

C.     Carbon dioxide

D.    Oxygen

14.  The best method of measuring the growth rate of a seedling is by

A.    Taking records of dry weight.

B.     Measuring the fresh weight.

C.     Observing the increase in volume.

D.    Observing the increase in the size of the leaves.

15.  Which one of these methods is not important in the maintenance of soil fertility on a given piece of land?

A.    Practicing crop rotation.

B.     Addition of organic manure

C.     Maintaining of vegetation cover.

D.    Burning of the grass in the plot regularly.

16.  Short sightedness is caused by the

A.    Lens becoming thicker.

B.     Suspensory ligament becoming shorter.

C.     Contraction of the cilliary muscles.

D.    Expansion of iris muscles.

17.  Which one of the following soil types has the highest capillarity?

A.    Silt

B.     Loam

C.     Clay

D.    Sand

18.  When blood passes from the lungs to the kidney it has to go through the

A.    Pulmonary artery, tricuspid valve and aorta.

B.     Pulmonary vein, bicuspid valve and aorta.

C.     Anterior venacava, tricuspid valve and aorta.

D.    Posterior venacava, bicuspid valve and aorta.

19. IMAGE

In a germinating grain, the function of X is to

A.    Absorb food from the endosperm.

B.     Provide the first leaves.

C.     Hydrolyze the food in the endosperm.

D.    Protects the plumule.

20.  A mammalian embryo exchanges materials with its mother by

A.    Osmosis.

B.     Secretion.

C.     Circulation.

D.    Diffusion.

21.  Which one of the following statements is the most appropriate definition of respiration?

A.    The oxidation of sugar to produce energy and water.

B.     Breathing in oxygen, oxidation of food and release of water, carbon dioxide and energy.

C.     The exchange of oxygen and carbon dioxide in the lungs.

D.    The oxidation of sugar to produce carbon dioxide and energy.

22. IMAGE

The root modification shown by Y on page 5 is for

A.    Storage.

B.     Excretion.

C.     Breathing.

D.    Extra support.

23.  In what part of the green flowering plant does meiosis occur?

A.    Seed

B.     Flower

C.     Fruit

D.    Shoot apex

24.  A bat is classified as a mammal because

A.    It does not possess feathers.

B.     It has specialized teeth.

C.     It has four limbs.

D.    Its digits have claws.

Study the web below and use it to answer questions 25 and 26.

IMAGE

25.  In this food web, which of the following groups of organisms are primary consumers?

A.    Pond leeches and water fleas.

B.     Pond snails and unicellular animals.

C.     Hydra and water beetles.

D.    Bacterial and water fleas.

26.  In this food web which one of the following groups of organisms are decompress?

A.    Unicellular green algae

B.     Water beetles

C.     Water lice

D.    Bacteria

27.  Which one of the following features is typical of the class insect?

A.    Jointed legs.

B.     Three body parts.

C.     Complete metamorphosis.

D.    Exoskeleton

28.  Which one of the following types of feathers is most widespread?

A.    Covert feather.

B.     Filiplumes.

C.     Quill feathers.

D.    Down feathers.

29.  Which of the following pairs of cells does not have nuclei when mature?

A.    Sieve tube cells and companion cells.

B.     Erythrocytes and leucocytes.

C.     Sieve tube cells and crythrocytes.

D.    Companion cells and leucocytes.

30.  Which one of the following processes needs energy?

A.    Absorption of water by root hairs.

B.     Gaseous exchange in the alveoli.

C.     Loss of turgidity by a plant cell.

D.    Absorption of mineral salts by root hairs.

 

SECTION B

Answer all questions in this section. Answer must be written in the spaces provided.

31.  a) (i) What is meant by the term mutation?

b) The gene for normal production of hemoglobin is dominant to the mutant gene which causes sickle cell anaemia. If a female heterozygous for the sickle cell anaemia marries a normal man, illustrate, using suitable symbols, the possible genotypes and phenotypes of offspring.

32.  a) Distinguish between endocrine and exocrine glands.

b) Below is a diagram of a human female showing the location of two endocrine glands.

IMAGE

Name the glands A and B and one hormone produced by each.

c) Give three effects of adrenaline in the body.

33.  Figure 2 (a) shows a vertical section of the end region of a growing root and figure 2 (b) shows an enlargement of a cell from the root.

IMAGES

a)     (i) Name the region labelled A

(ii) How does growth occur in the region labelled B?

(iii) Describe briefly what happens to the cells in the region labelled C.

(iv) What structures might be expected to grow at the region marked D?

b)    State the function of region marked A.

c)     Figure 2 (b) shows a cell from region B.

(i)    Name the process taking place in the cell.

(ii)   Briefly describe what is happening at this particular stage of the process.

34.  The graph below shows the relationships between body temperatures and external temperatures in human being and a lizard.

GRAPH

a)     What happens to the temperature of each organism as the external temperature increases?

Human.........................................................................................................

Lizard ...........................................................................................................

b)    Humans are sometimes described as warm-blooded (homoiotheric). State the advantage of this condition.

c)     Suggest how a lizard living in hot desert conditions might avoid overheating if external temperatures rose above 400c.

 

SECTION C

Answer any two questions from this section.

35.  a) How does gaseous exchange take place in an insect?

b) How does gaseous exchange in insects differ from that in mammals?

36.  Describe an experiment you would carry out to test for the presence of starch in a leaf.

37.  a) Draw a well labelled diagram of a human female reproductive system.

b) Outline the events that lead to the fertilization of the ovum in the human female.

38.  a) Describe the structure of a motor neuron.

b) (i) What is meant by reflex action?

(ii) By means of a diagram, show the path followed by a nerve impulse during a reflex action.

 

 

 

Wednesday, 30 May 2012 13:36

BIOLOGY 1997

Written by B.K.Sharon

PAPER 1

THOERY

SECTION A

Answer all questions in this section. For each question select the most correct option and write the letter representing it in the box provided.

1.     Which of the following processes need energy?

A.    Osmosis

B.     Diffusion

C.     Plasmolysis

D.    Active transport

2.     What is the normal blood sugar level in an adult person?

A.    140 mg/ 100cm3

B.     100mg/ 100 cm3

C.     90 mg/ 100 cm3

D.    80 mg/ 100 cm3

3.     The diagram in figure 1 is of a transverse section of a plant part.

IMAGE

From which one of the following was the section taken? A

A.    Monocotyledonous stem.

B.     Monocotyledonous root.

C.     Dicotyledonous root.

D.    Dicotyledonous stem.

4.     Which one of the following represents a reflex are?

A.    Receptor - motor neuron - central nervous system - sensory neuron - effectors.

B.     Receptor - sensory neuron - effectors - central nervous system - motor neuron.

C.     Receptor - central nervous system - motor neuron - sensory neuron - effectors.

D.    Receptor - sensory neuron - central nervous system - motor neuron - effectors.

5.     The following are characteristics of insects.

(i)    They undergo complete metamorphosis.

(ii)   They have 1 or 2 pairs of wings

(iii)  They have 3 pairs of jointed legs.

(iv)  Their bodies are divided into 3 main parts.

(v)   They posses exoskeletons.

Which of them are common to all insects?

A.    (iii), (iv) and (v)

B.     (i), (ii) and (iii)

C.     (i), (iii) and (v)

D.    (iii), (ii) and (v)

6.     Which one of the following combination of words about amoeba are related?

A.    Pseudopodia, reproduction

B.     Nucleus, movement

C.     Contractile vacuole, water

D.    Ectoplasm, digestion

7.     The results of an experiment to determine percentage of water in a sample of soil are shown below:

Mass of crucible = 15g

Mass of crucible plus soil = 30 g

Mass of crucible plus soil after drying = 25g

What is the percentage of water?

A.    33.3%

B.     18.7%

C.     66.7%

D.    20.0%

8.     Which of the following reasons supports natural feeding of baby on mother's milk? Mother's milk is

(i)    Easy to digest.

(ii)   Made up mainly of carbohydrates.

(iii)  Contains correct antibodies.

(iv)  Fosters relationship between mother and baby.

A.    (i) and (ii)

B.     (ii) and (iii)

C.     (ii), (iii) and (iv)

D.    (i), (iii) and (iv)

9.     The milk teeth in humans consist of

A.    Incisors only.

B.     Incisors and canines.

C.     Incisors, canines and premolars.

D.    Incisors and premolars.

10.  Which one of the following is not transported in blood?

A.    Amylase

B.     Urea

C.     Insulin

D.    Sodium chloride

11.   Which one of the following is not a primary function of roots?

A.    Conduct water and mineral salts.

B.     Anchor the plant into the soil.

C.     Store food and water.

D.    Absorb water and mineral salts.

12.  Within an ecosystem, the total number of secondary consumer must be

A.    Less than the total number of herbivores.

B.     Greater than the total number of herbivores.

C.     Equal to the total number of producers.

D.    Constant year after year.

13.  Which one of the following hormones is not secreted from the pituitary gland?

A.    Gonadotrophic hormone

B.     Luteinizing hormone

C.     Progesterone hormone

D.    Follicle stimulating hormone

14.  Why is it necessary to keep both eyes open when you are using a monocular microscope?

A.    Straining one eye is avoided

B.     One eye is set on the drawing paper

C.     It enables one to see the object clearly

D.    It eases the control of the adjustment knobs

15.  Which one of the following food substances are not changed by the gut enzymes?

A.    Lipids and vitamins

B.     Minerals and vitamins

C.     Minerals and disaccharides

D.    Lipids and lactose

16.  The structures in insects that serve as respiratory surfaces for gaseous exchange are

A.    Trachea

B.     Bronchioles

C.     Tracheoles

D.    Spiracles

17.  A man's urine gave a positive test with Benedict's solution. What is the best deduction about this man?

A.    He had been eating a lot of sugar.

B.     There was too much insulin in his blood.

C.     There was too much glycogen in his blood

D.    He was suffering from diabetes.

18.  Figure 2 below is a diagram showing a plan of the pentadactyl limb

IMAGE

What part is represented by letter X?

A.    Femur

B.     Humerus

C.     Radius

D.    Ulna

19.  What do the rhizobium bacteria gain in their association with leguminous plant?

A.    Air

B.     Heat

C.     Shelter

D.    Nitrates

20.  Which of the following is the best advantage of crop rotation?

A.    It helps reduce soil erosion.

B.     The growth of weeds is brought under control.

C.     It prevents exhaustion of particular mineral salts from the soil.

D.    It helps improve soil conditions.

21.  Which one of the following events does not occur following the contraction of the ventricles in mammalian heart?

A.    Blood flows from ventricles into arteries.

B.     The blood pressure increases in the aorta.

C.     Artrio-ventricular valves open

D.    Arterial valves open.

22.  Which of the following mineral elements are for bone formation?

A.    Iodine, sodium and calcium.

B.     Iron, fluorine and calcium.

C.     Phosphorus, sodium and fluorine.

D.    Calcium, fluorine and phosphorus.

23.  What is the function of albumen in an egg? It

A.    Is a source of fat and protein for the embryo?

B.     Is a source of protein and water for the embryo.

C.     Suspends the embryo.

D.    Stores embryo's excretory products.

24.  A heterozygous red flowered plant (Rr) is crossed with a homozygous white flowered plant (rr). If R is dominant over r, what will be the phenotypes of the off springs?

A.    All red

B.     All white

C.     Pink and white

D.    Red and white

25.  The dry fruit which splits open along both sutures in

A.    A follide

B.     A capsule

C.     An Achene.

D.    A legume.

26.  Which one of the following structures is not essential in the life of a tadpole?

A.    Lungs

B.     Horny jaws

C.     Gills

D.    Tail

27.  The diagram in figure 3 below represents the frequency of occurrence of a character in human population.

GRAPH

Which one of the following characters in the population does not conform to this pattern?

A.    Height

B.     Weight

C.     Length of feet

D.    Eye color

28.  Which of the following is not a function of the liver?

A.    Storage of vitamins.

B.     Manufacture of plasma proteins

C.     Storage of proteins

D.    Formation of bile

29.  Which of the following cells in the leaf contain the least number of chloroplasts?

A.    Palisade cells

B.     Guard cells

C.     Epidermal cells

D.    Spongy mesophyll cells

30.  Which one of the following organisms is not a heterotrophy?

A.    Mushroom

B.     Alga

C.     Tick

D.    Grass hopper

 

SECTION B

Answer all questions in this section. Answer must be written in the spaces provided.

31.  a) What do you understand by the following terms?

(i)    Habitat

(ii)   Ecosystem

b) There are four possible atrophic levels that can exist in a food chain. State them below.

(i) ........................................................................................................................

(ii) ........................................................................................................................

(iii) .................................................................................................................

(iv) .............................................................................................................

c) give an example of food chain consisting of four levels of organisms found in a grassland.

d) Construct a diagram of a food web which may exist in a freshwater lake in Uganda, comprising of the following organisms:

Tadpole, Green alga, Heron, Saprophytic bacteria, small fish, big fish and mosquito larvae.

32.  In an experiment, a long winged male drosophila was crossed with a short winged female drosophila. All the offspring in the F1 generation were long winged. When two members of the F1 generation were mated, the F2 generation consisted of 62 long winged flies and 21 short winged flies.

a)     Suggest an explanation why all the F1 generation flies were long winged.

b)    (i) What type of flies would develop from a mating between short winged flies in the second generation?

(ii) Give a reason for your answer.

c)     Mating between a short winged fly in F2 generation with a long winged fly in F1 generation produced 90 flies. How many of them long winged? Show your working.

33.  The diagram in figure 4 shows part of the body of a man.

IMAGE

a)     Name the parts labelled A to E.

A .............................................................................................................

B .............................................................................................................

C .............................................................................................................

D ............................................................................................................

E ............................................................................................................

b)    (i) Name the hormone made in the male brings about the secondary sexual characteristics.

(ii) On the diagram, write H where the hormone is made.

(iii) Name two secondary sexual characteristics in the human male.

c)     What is the function of part D?

d)    From which organ would fluid in the tube E come from?

34.  The diagram in figure 5 shows the structure of a villus.

IMAGE

a)     Label parts marked A, B, C and D.

A ...........................................................................................................

B ............................................................................................................

C ..........................................................................................................

D ..........................................................................................................

b)    What food substances enter

(i) A?

(ii) B?

c)     State two factors which make a villus an effective absorbing structure.

(i) ..................................................................................................

(ii) ..................................................................................................

d)    How does the absorbed food in B reach the general circulation?

e)     State two nutrients which are absorbed in the gut before reaching the villus.

(i) ...................................................................................................

(ii) ..................................................................................................

 

SECTION C

Answer any two questions.

35.  a) What is soil erosion?

b) State the various types of soil erosion.

c) Explain how man's activities may lead to soil erosion.

36.  a) Describe how plants lose water through their leaves.

b) Describe two features of plants and two features of animals which help them reduce water loss in dry conditions.

37.  a) What is meant by the word metamorphosis?

b) Using a written description and labelled diagrams, describe the life cycle of a grasshopper.

38.  a) What is respiration?

b) State three differences between aerobic and anaerobic respiration.

c) Describe gaseous exchange in a frog.

Wednesday, 30 May 2012 10:26

BIOLOGY 1998

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

Answer all questions in this section. For each question select the most correct option and write the letter representing it in the box provided.

1.     What would happen to an enzyme if the temperature of its medium was increased to above 500c? the enzyme would be

A.    Killed

B.     Activated

C.     Denatured

D.    Inactivated

2.     In which of the following does active transport not occur?

A.    Kidney tubules

B.     Phloem sieve tubes

C.     Xylem vessels

D.    Ileum Villi

3.     Which one of the following is adaptation of reptiles for terrestrial environment?

A.    Limbs

B.     Lungs

C.     Scales

D.    Elongated body

4.     Figure 1 below shows a longitudinal section through a maize grain.

IMAGE

Which of the parts 1 - 4 of the grain would you expect to decrease in weight during germination?

A.    1

B.     2

C.     3

D.    4

5.     Which one of the following parts of the ear, transmits sound waves from the middle ear to the inner ear?

A.    Tympanic membrane

B.     Ossicles

C.     Auditory nerve

D.    Oval window membrane

6.     Which one of the following methods would you use to estimate the frequency of a plant species in area?

A.    Quadrant method

B.     Belt transect

C.     Line transect

D.    Random sampling

7.     An unknown sample of blood was found to agglutinate with blood of group AB, but not with blood of O. what was the blood group of the unknown sample?

A.    O

B.     AB

C.     A

D.    B

8.     A rabbit is able to utilize cellulose because it

A.    Has symbiotic bacteria in the stomach

B.     Has symbiotic bacteria in the ceacum

C.     Has a very long alimentary canal

D.    Secretes the enzyme cellulose

9.     Which one of the following factors is not important as far as nutrition of the common mould is concerned?

A.    It produces large quantities of spores.

B.     It can respire anaerobically.

C.     It has a highly branched mycelium.

D.    It secrets enzymes.

10.  In the human heart, the mixing of oxygenated and de-oxygenated blood is prevented by the

A.    Septum,

B.     Bicuspid valve,

C.     Tricuspid valve,

D.    Semilunar valve.

11.   Removal of the thyroid gland in a young child may lead to

A.    Stunted growth and mental retardation.

B.     Failure to develop secondary sexual characteristics.

C.     Development of diabetes

D.    Increased metabolic rate and restlessness.

12.   The following are physiological processes that occur in the body of a mammal.

(i)    Elimination of urea

(ii)   Regulation of salts in the body

(iii)  Regulation of water in the body

(iv)  Deamination of excess amino acids.

Which of them are carried out by the kidney?

A.    (i), (ii) and (iv)

B.     (ii), (iii) and (iv)

C.     (i),  (ii) and (iii)

D.    (ii) and (iii) only

13.  Which one of the following is a respiratory organ in an insect?

A.    Malphigian tubule

B.     Spiracle

C.     Trachea

D.    Zygote

14.  Which one of the following is a diploid cell?

A.    Pollen grain

B.     Ovum

C.     Spermatoon

D.    Alveolus

15.  What gas is likely to be evolved from a submerged aquatic plant placed in bright sunlight?

A.    Carbon dioxide

B.     Oxygen

C.     Hydrogen

D.    Nitrogen

16.  Which of the following is a characteristic of cervical vertebra?

A.    Broad neutral spine

B.     Long transverse processes

C.     Presence of vertebraterial canals

D.    Presence of facets

17.  Which one of the following has the least energy content in a food chain?

A.    Producer

B.     Secondary consumer

C.     Tertiary consumer

D.    Primary consumer

18.   A certain plant had the following characteristics:

Leaves reduced to spikes

Stomata shrunken in pits

Leaves covered with thick cuticle

Which one of the following would be the likely habitat for the plant?

A.    Open grass land

B.     Arid land

C.     Wet land

D.    Tropical rainforest

19.  Yellowing of leaves in growing maize plants indicates a deficiency of

A.    Calcium

B.     Sulphur

C.     Nitrogen

D.    Magnesium

20.  What are the products of digestion of lactose sugar?

A.    Glucose only

B.     Glucose and Galactose

C.     Fructose and Galactose

D.    Fructose and glucose

21.  Which one of the following is a characteristic of insects only?

A.    Exoskeleton

B.     Jointed legs

C.     Two pairs of wings

D.    Three body divisions

22.  Which of the following vegetative plants would appear earliest in a rocky habitat?

A.    Moss

B.     Lichens

C.     Algae

D.    Ferns

23.  Which one of the organisms below has a growth curve represented by the graph in figure 2?

GRAPH

A.    A bacterium

B.     An insect

C.     A human being

D.    A bony fish

24.  Which one of the following is a modified root?

A.    Sweet potato tuber

B.     Rhizome

C.     Irish potato tuber

D.    Corm

25.  Which one of the following hormones is responsible for ovulation in mammals?

A.    Oestrogen

B.     Progesterone

C.     Follicle stimulating hormone

D.    Luteinizing hormone

26.  Which of the following are characteristics of sandy soil?

A.    Poor aeration and poor drainage.

B.     Good water retention and poor drainage.

C.     Sticky when wet and poor drainage.

D.    Good aeration and good drainage.

27.  Which of the following is not true about mutation?

A.    Mutation may affect single genes or chromosomes.

B.     All mutations produce harmful effects.

C.     A mutant gene can be passed onto the offspring during fertilization

D.    Mutations are the raw materials for evolution.

28.  A maize grain is both a seed and a fruit because it

A.    shows hypogeal germination

B.     has a fused pericarp and testa

C.     shows two attachments or scars

D.    has both endosperm and cotyledon.

29.   Figure 3 below is an experimental set up to investigate the action of enzyme pepsin on egg albumen.

IMAGE

In which tube will the contents clear after some time?

30.  Which one of the following substances does not contain nitrogen?

A.    Glycerol

B.     Amino acids

C.     Amylase

D.    Urea

 

SECTION B

Answer all questions in this section. Answer must be written in the spaces provided.

31.   Figure 4 below, shows a mammalian urinary system.

IMAGE

a) Name the parts labelled A - F.

A ...........................................................  D .................................................

B ...........................................................  E ..................................................

C ...........................................................  F ..................................................

b)    Briefly explain why the concentration of urea in B is less than that in C.

c)     What is the function of E?

d)    A sample of urine was found to contain sugar.

(i)     Suggest the type of sugar likely to be contained in the urine sample.

(ii)    What hormone is likely to be deficient in the person from whom the urine sample was taken?

(iii)   Name the disease that the person is likely to be suffering from.

e)     Another individual was found to be passing out a lot of urine but without sugar and complaining of thirst most of the time.

(i)    Suggest a hormone that is deficient in this individual.

(ii)   Name the organ which produces the hormone referred to in (e) (i) above.

32.  a) Give five differences between respiration and photosynthesis.

b) Give three ways in which respiration is important to living organisms.

c) Name two commercial uses of anaerobic respiration.

33.  a) What is germination?

b) State the external factors that affect germination.

c) Figure 5 below shows a growth curve of a bean seedling.

GRAPH

(i) Why does the mass of the seedling increase between day 0 and day 4?

(ii) What has caused a drop in the mass between day 4 and day 6?

(iii)  Give reason for the steady increase in mass after day 6.

34.  Figure 6 below shows the nitrogen cycle.

IMAGE

a)     Name the processes taking place at A, B, C, D and E.

A .............................................................................................................

B .............................................................................................................

C .............................................................................................................

D ............................................................................................................

E ............................................................................................................

b)    (i) How is the process at B useful to plants?

(ii) What organisms are responsible for the process at C?

c)     State the importance of the process at A in the cycle.

 

SECTION C

Answer any two questions.

35.  a) outline the mechanism of

(i)    inspiration

(ii)   expiration

in a bony fish

b) How are grills adapted for gaseous for exchange in a bony fish?

36.  a) What is self pollination?

b) How is self pollination naturally prevented in plants?

c) Describe the features of a flower that favour pollination by insects.

37.   a) Giving tow examples in each case, explain the following:

(i)     parasitism

(ii)    commensalism

(iii)   symbiosis

b) How is the tape worm adapted to its parasitic mode of life?

38.  a) What is transpiration?

b) Describe an experiment to show that transpiration occurs in plants.

c) State the factors that effect transpiration in plants.

Wednesday, 30 May 2012 08:18

BIOLOGY 1999

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

Answer all questions in this section. For each question select the most correct option and write the letter representing it in the box provided.

1.     Figure 1 below shows the structure of a part of the lower epidermis of a leaf.

IMAGE

What is the structure labelled T?

A.    Stoma

B.     Vacuole

C.     Chloroplast

D.    Guard cell

2.     Which of the following blood vessels transports blood most rich in nutrients?

A.    Pulmonary artery.

B.     Hepatic portal vein.

C.     Mesenteric artery.

D.    Renal vein

3.     Which one of the following is an example of biological control of pests?

A.    Application of pesticides.

B.     Destruction of pests' habitats.

C.     Interruption of pests' breeding cycle.

D.    Introduction of pests' predators.

4.     The effect of unidirectional light on the distribution of auxin in the tip of a plant shoot is

A.    Uniform distribution of auxin around the tip.

B.     Reduction in concentration of auxin on the illuminated side of the plant.

C.     Increase in auxin on the illuminated side of the plant.

D.    Inhibition of movement of auxin down the plant.

5.     Which of the following is a function of thyroxin hormone?

A.    Promotes development of follicle in the ovary.

B.     Prepares the body for fright - flight action.

C.     Controls body metabolic rate.

D.    Regulates sugar content of the body.

6.     Which of the following is an example of a berry?

A.    Avocado

B.     Passion

C.     Groundnut

D.    Cotton

7.     The mode of feeding displayed by a Mucor is described as

A.    Holozoic

B.     Filter feeding

C.     Parasitic

D.    Saprophytic

8.     What is function of the Eustachian tube in the human ear?

A.    Detection of body posture

B.     Transmission of sound waves to the middle ear.

C.     Equalizing pressure in the middle ear.

D.    Transmission of sound waves to the inner ear.

9.     If a man of blood A is married to a woman of blood group O, what are the possible genotypes of their children?

A.    AA, OO

B.     AA, AO

C.     AO, OO

D.    AO only

10.  What relationship exists between a groundnut plant and nitrogen fixing bacteria in its root nodules?

A.    Parasitism

B.     Saprophytism

C.     Naturalism

D.    Symbiosis

11.   Which type of soil has the following characteristics?

(i)     Heavy to cultivate.

(ii)    Rich in dissolved minerals

(iii)   High capillarity

A.    Loam

B.     Clay

C.     Sand

D.    Silt loam

12.  In figure 2 below, which part transports water and dissolved minerals?

IMAGE

13.  Which of the following features belong to both an arachnidan and an insect?

A.    Cuticle and two pairs of wings.

B.     Six legs and two pairs of wings.

C.     Six legs and antennae.

D.    Jointed legs and cuticle.

14.  Which one of the following statements best explains why urine does not normally contain glucose?

A.    Glucose molecules are too large to pass through the capillaries of the glomerular.

B.     Glucose present in the renal tubule is changed to carbon dioxide and water.

C.     All the glucose filtered is re-absorbed back into the blood in the renal tubules.

D.    The bladder re-absorbs all the glucose filtered.

15.  Aerobic respiration is more efficient than anaerobic respiration because it

A.    Uses more oxygen.

B.     Yields lactic acid.

C.     Uses less oxygen.

D.    Yields more energy.

16.  In humans, the hormone progesterone stimulates the

A.    Formation of egg cells.

B.     Formation of sperm cells.

C.     Production of milk by a lactating mother.

D.    Thickening of the uterine wall.

17.  What is the destination of the impulses moving along the nerve fibre marked Z in figure 3 below?

A.    The spinal cord

B.     The brain

C.     The effectors organ

D.    The receptor organ

18.  Which of the diseases listed below is a result of lack of the Anti-Diuretic Hormone (ADH) in the body?

A.    Diabetes mellitus

B.     Anaemia

C.     Goiter

D.    Diabetes inspidus

19.   The following are body responses to change in temperature of a mammal:

(i)     Shivering

(ii)    Increased blood supply to the skin.

(iii)   Decreased of erector Pilli muscle.

Which two of these are responses to a fall in body temperature?

A.    (i) and (ii)

B.     (ii) and (iii)

C.     (iii) and (iv)

D.    (i) and (iii)

20.  Which one of the following pairs of bones forms a ball and socket joint?

A.    Humerus and ulna.

B.     Femur and pelvis

C.     Humerus and radius

D.    Femur and tibia

21.  Which of the following characteristics show discontinuous variation?

A.    Body weight

B.     Blood groups

C.     Size of leaves

D.    Color of flowers

22.  What one of the following responses is a directional growth movement?

A.    Taxis

B.     Reflex

C.     Tropic

D.    Nastic

23.  The blood serum of universal donor contains

A.    Antigens A

B.     Antigens B

C.     Neither antigens A nor B

D.    Both antigens A and B

24.  Meiosis leads to the production of

A.    Two daughter cells each with original number of chromosomes.

B.     Four daughter cells each with original number of chromosomes.

C.     Two daughter cells each with half the original number of chromosomes

D.    Four daughter cells each with half the original number of chromosomes.

25.  Which one of the following organisms carries out intracellular digestion?

A.    Fungi

B.     Algae

C.     Amoeba

D.    Hookworm

26.   If energy from the sun was cut off from an ecosystem containing the following organisms.

(i)    Green plants.

(ii)   Herbivores.

(iii)  Saprophytes.

(iv)  Carnivores.

In which order would the organizations die out?

A.    (i), (ii), (iii) and (iv)

B.     (i), (ii), (iv) and (iii)

C.     (iii), (i), (ii) and (iv)

D.    (i), (iii), (ii) and (iv)

27.  A plant with poorly developed roots is likely to be growing in a soil that is deficient in

A.    Sulphur.

B.     Phosphorus.

C.     Magnesium.

D.    Iron.

28.  In fish, the fins which are used in propulsion movements are

A.    Caudal

B.     Dorsal

C.     Pelvic

D.    Ventral

29.  Phagocytosis is the process whereby white blood cells

A.    Ingest bacteria.

B.     Cause the bacteria to stick together.

C.     Dissolve the outer coats of invading bacteria.

D.    Neutralize bacteria.

30.  The following are factors that affect the rate of transpiration:

(i)    High temperature.

(ii)   High relative humidity.

(iii)  Low atmospheric pressure.

(iv)  Low light intensity

Which two of these would favour increased transpiration?

A.    (i) and (ii)

B.     (i) and (iii)

C.     (ii) and (iv)

D.    (iii) and (iv)

 

SECTION B

Answer all questions in this section. Answers must be written in the spaces provided.

31.  a) What is an enzyme?

b) Study the experimental set up in figure 4 below and answer the questions that follow:

IMAGE

(i)    What is being investigated?

(ii)   Suggest what was observed in each of the test tubes.

(iii)  Explain the observations suggested in (b) (ii) above.

32.  a) Distinguish between predator and prey?

b) Figure 5 below shows predator/ prey relationship. Study the figure and answer the questions that follow:

IMAGE

(i)    Describe the relationship between the predator and prey.

(ii)   Explain the relationship of the predator and prey described in (b) (i) above.

(iii)  Name two other external factors that may affect the population of the prey in the habitat.

33.  a) What is soil erosion?

b) Name four types of soil erosion.

c) State the causes of soil erosion.

d) How does mulching help the farmer in

(i) Water conservation?

(ii) Soil conservation?

34.  a) (i) State the difference between cross pollination and self pollination.

(ii) Give three structural features of flowers that ensure cross pollination.

b) Give five adaptations of flowers for insect pollination.

 

SECTION C

Answer any two questions

35.   Describe an experiment to show that oxygen is produced during photosynthesis.

36.  a) Give three secondary sexual characteristics in a human female.

b) Describe the main events that occur during the menstrual cycle in a mammal.

37.  a) Describe the life cycle of a housefly.

b) What is the economic importance of a housefly?

c) How would you minimize the spread of housefly?

38.  a) Define:

(i)    Phototropism.

(ii)   Geotropism.

b) Describe an experiment you would carry out to determine the effects of gravity on the root of a dicotyledonous plant.

 

 

 

 

 

Tuesday, 29 May 2012 09:31

BIOLOGY 2000

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

Answer all questions in this section. For each question select the most correct option and write the letter representing it in the box provided.

1.     The following are characteristics of blood vessels:

(i)    Presence of valves.

(ii)   Thick walls.

(iii)  Wide lumen.

(iv)  Elastic walls.

Which of the characteristics belong to veins?

A.    (i) and (ii)

B.     (i) and (iii)

C.     (ii) and (iii)

D.    (iii) and (iv)

2.     Mucor undergoes a sexual reproduction to produce

A.    Spores.

B.     Zoospores.

C.     Zygospores.

D.    Sporangia

3.     The fins which keep a fish stable in water are the

A.    Anal and dorsal fins.

B.     Dorsal and pelvic fins.

C.     Caudal and pelvic fins.

D.    Pelvic and pectoral fins.

4.     Which one of the following is correct about diving cells at the tip of plant shoots?

They

A.    Have large vacuoles.

B.     Are specialized.

C.     Have soft cell walls.

D.    Have rigid cell walls.

5.     Which one of the following contains the highest concentration of proteins?

A.    Blood plasma.

B.     Glomerular filtrate.

C.     Urine.

D.    Serum

6.     Which one of the following would be observed in a plant growing in a soil lacking magnesium?

A.    Poorly developed shoot system.

B.     Yellowing of leaves.

C.     Poorly developed root system.

D.    Yellowing of buds.

7.     What mode of nutritions is used by Rhizopus?

A.    Heterotropism.

B.     Autotropism.

C.     Parasitism

D.    Saprophytism.

8.     Which one of the following would be the first to colonize a rocky surface?

A.    Lichens.

B.     Mosses.

C.     Shrubs.

D.    Ferns.

9.     The blood constituents that help in the formation of blood clot at the site of an injury are

A.    Platelets and erythrocytes.

B.     Hormones and plasma.

C.     Platelets and leucocytes.

D.    Platelets and fibrinogen.

10.  Figure 1 shows a gill of a fish.

IMAGE

The name and function of part labelled A is

A.    Gill filaments for gaseous exchange.

B.     Gill rakers for filtering food.

C.     Gill bar for support.

D.    Gill arch for increasing surface area.

11.   Which one of the following would not be found in the glomerular filtrate?

A.    Fibrinogen.

B.     Glucose.

C.     Mineral salts.

D.    Urea.

12.  Which one of the following is an example of discontinuous variation?

A.    Height.

B.     Weight.

C.     Eye color in Drosophila.

D.    Skin color.

13.  Which one of the following sets consists of substances that are stored in the liver?

A.    Glucose, iron and vitamin D.

B.     Iron, glycogen and vitamin D.

C.     Glucose, glycogen and vitamin D.

D.    Iron, glycogen and amino acids.

14.  Albinism is caused by having a double recessive gene for skin pigmentation. What is the probability of the children having normal skin color if an albino woman marries a man who is heterozygous for albinism?

A.    100%

B.     75%

C.     50%

D.    25%

15.  The data below shows the amount of carbon dioxide in inhaled air, rate of breathing at rest and volume of air in a breath, in humans:

Percentage of carbon dioxide in inhaled air = 0.025%.

Number of breaths per minute = 36.

Volume of one breath taken in at rest = 500 cm3.

The volume of carbon dioxide inhaled per minute while at rest is

A.    0.9 cm3

B.     45 cm3

C.     12.5 cm3

D.    450 cm3

16.  How is lactic acid produced in muscles got rid of? By

A.    Converting it into water.

B.     Storing it in the liver.

C.     Converting it into ethanol.

D.    Oxidation.

17.  Blood flows in the pulmonary artery at a lower pressure than in aorta because in the pulmonary circulation

A.    Blood travels a shorter distance.

B.     The right ventricle has thinner walls.

C.     The vessel carrying blood is smaller.

D.    Fewer organs are supplied.

18.  Which happens to the following is an example of a reflex action?

A.    Eating.

B.     Screaming after kicking a stone.

C.     Riding.

D.    Salivating on smelling food.

19.  What happens to insect wings when depressor muscles are relaxed? The wings

A.    Move down wards.

B.     Move up wards.

C.     Rotate freely.

D.    Move in three directions.

20.  Which one of the following parasites is transmitted by Anopheles mosquito?

A.    Filarial worm.

B.     Trypanosome.

C.     Plasmodium.

D.    Schistosoma.

21.  The following are body secretions:

(i)    Amylase,

(ii)   Trypsin,

(iii)  Hydrochloric acid,

(iv)  Pepsin,

(v)   Rennin.

Which of them are contained in gastric juice?

A.    (i) and (iii)

B.     (ii) and (iv)

C.     (iii) and (v)

D.    (i) and (ii)

22.  What is the main function of the phloem in green plants?

A.    Transporting water.

B.     Supporting the plant.

C.     Transporting mineral salts.

D.    Transporting manufactured food.

23.  Which of the following is an example of a modified root?

A.    Irish potato tuber.

B.     Cassava tuber.

C.     Rhizome.

D.    Corm.

24.  Which of the following events occur during inhalation in a mammal?

A.    Diaphragm contracts, ribs raised.

B.     Diaphragm relaxes, ribs lowered.

C.     Internal intercostals muscles contract, pressure in chest cavity increases.

D.    Internal intercostals muscles relax, pressure in chest cavity increases.

25.  Which one of the main function of the choroid layer in the human eye?

A.    Focusing rays of light on the retina.

B.     Supplying nutrients to the eye.

C.     Bringing about accommodation.

D.    Controlling amount of light entering the eye.

26.  Which one of the following pairs of hormones is produced by reproductive organs in mammals?

A.    Follicle stimulating hormone and testosterone.

B.     Oestrogen and luteinizing hormone.

C.     Progesterone and testosterone.

D.    Insulin and oestrogen.

27.  When a homozygous black mouse (BB) was mated with homozygous white mouse (ww), the offspring were all brown. What would be the color of the mice produced if F1 offspring is crossed with a homozygous white parent?

A.    3 brown: 1 white.

B.     1 brown: 3 white.

C.     1 brown: 1 white.

D.    All white.

28.  The scheme below shows a food chain with corresponding concentrations of organic chloride in milligram's:

Green plants - herbivorous - predatory - lizard.

Bug                 bug

0.01               0.9                     2.3             2.8

Which does the tissue of the lizard contain the highest concentration of the organic chloride? Because the

A.    Lizard cats all the organisms in the food chain.

B.     Organic chloride remains persistent in the food chain.

C.     Organic chloride is cumulative in the issues of the organisms.

D.    Organic chloride is not toxic to lizard.

29.  Which one of the following structures is found in cervical vertebrae only?

A.    Centrum.

B.     Neural spine.

C.     Transverse process.

D.    Vertebra - arterial canal

30.  The forces which mostly help water to move up a tall plant are

A.    Osmosis and diffusion.

B.     Capillarity and transpiration.

C.     Osmosis only.

D.    Capillary and osmosis.

 

SECTION B

Answer all questions in this section. Answers must be written in the spaces provided.

31.  Figure 2 below shows an experimental set up to demonstrate transpiration in plants.

IMAGE

a)     Explain why:

(i)    Vaseline is smeared between the glass plate and the bell jar.

(ii)   Polythene bag is wrapped around the pot and tied at the base of the plant.

b)    (i) What will be observed in this experiment?

(ii) How do you test for the identity of the substance observed in (b) (i)?

c)     Describe the set up of the control for this experiment.

d)    State two factors which affect the results of this experiment.

32.  a) What is an enzyme?

b) State three factors which affect enzyme action.

c) The optimum pH for enzyme X is 2.00 and for enzyme Y is 9.00. suggest the names of the enzymes X and Y, and name the parts of the alimentary canal where you would expect to find each enzyme.

 

Name of enzyme parrt of alimentary canal the enzyme is found

X     

Y

...................................

...................................

...........................................

...........................................


 

d) State two enzymes contained in the pancreatic juice, the food substance acted on by each enzyme and the product formed in each case.

 

Enzyme Food substance acted upon Product formed

(i) ....................

(ii) ...................

.........................................

..........................................

........................

........................


 

33.  Figure 3 below shows a cross section of part of a plant.

IMAGE

a)     Name the parts labelled 1 to 5.

1 ...............................................................................................................

2 ...............................................................................................................

3 .......................................................................................................

4 .......................................................................................................

5 .......................................................................................................

b)    Giving a reason, state the part of the plant from which the section was taken.

Part of plant ...................................................................................

Reason .............................................................................................

c)     (i) State the functions of the parts labelled 3 and 4.

3 ........................................................................................................

4 ........................................................................................................

(ii) Give two similarities between the cells in part labelled 3 and those found at the tips of growing shoots.

34.  Figure 4 shows a longitudinal section of a human skin.

IMAGE

a)     (i) Name the parts labelled A to F.

A ...........................................................................................................

B .........................................................................................................

C ............................................................................................................

D ...........................................................................................................

E ............................................................................................................

F ............................................................................................................

(ii) State the function of each of the parts labelled A, B, D and F

A ..............................................................................................................

B ..............................................................................................................

D .............................................................................................................

F ...............................................................................................................

b)    Using any one observable feature on the diagram, suggest the type of temperature condition the skin is responding to. State the observable feature as a reason for your answer.

Temperature condition .........................................................................

Observable feature ................................................................................

 

SECTION C

Answer any two questions.

35.  Describe an experiment to show that carbon dioxide is necessary for photosynthesis.

36.  a) What is sexual reproduction?

b) Give the advantages of sexual reproduction plants.

c) Describe how sexual reproduction occurs in a Mucor.

37.  Describe human activities which may cause environmental pollution.

38.  a) What is the importance of water to animals?

b) Describe how water balance in the mammalian body is maintained.

Monday, 28 May 2012 11:25

BIOLOGY 2001

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

1.     Which one of the following would occur if a potato strip was placed in distilled water?

A.    Increase in length.

B.     Strip would soften.

C.     Decrease in length.

D.    Remain unchanged.

2.     When a seeding is fixed on a clinostat and placed in a horizontal position, the shoot continues to grow horizontally, but without the clinostat it bends upwards. Which one of the following is true about the role of the clinostat?

A.    Enables the seedling to receive uniform light.

B.     Causes auxin to accumulate on the lower side of the seedling.

C.     Causes auxin to accumulate uniformly on all sides.

3.     The following are some features of lower plants

(i)    Reproduce by spores.

(ii)   Lack vascular tissues.

(iii)  Grow in damp places.

(iv)  Have simple stem and leaves.

Which of the features belong to both mosses and ferns?

A.    (i) and (iv)

B.     (i) and (iii)

C.     (ii) and (iii)

D.    (iii) and (Iv)

4.     Which part of a flowering plant is represented by figure 1 below?

IMAGE

A.    Monocotyledonous stem.

B.     Dicotyledonous stem

C.     Monocotyledonous root.

D.    Dicotyledonous root.

5.     The following are products of tissue respiration in living organisms.

(i)    Energy.

(ii)   Carbon dioxide.

(iii)  Water.

(iv)  Ethanol.

(v)   Lactic acid.

Which of them are common to both aerobic and anaerobic respiration in plants?

A.    (i) and (ii)

B.     (ii) and (iii)

C.     (i), (ii) and (iii)

D.    (ii), (iv) and (v)

6.     A student wanted to determine the percentage of air in a soil sample. The following measurements were obtained.

Volume of dry soil = 250 cm3

Volume of water added = 160 cm3

Volume of mixture of soil + water = 380 cm3

What was the percentage of air in the soil sample?

A.    7.9

B.     12

C.     25

D.    34

7.     Which one of the following groups of animals uses gills, skin, buccal cavity and lungs for gaseous exchange at some stage in their life cycle?

A.    Fish

B.     Amphibians

C.     Reptiles

D.    Mammals

8.     A student noted the following characteristics on a vertebra

(i)     Long neural spine

(ii)    Wide neural canal

(iii)   Short transverse process.

The vertebra was

A.    Cervical

B.     Atlas

C.     Thoracic

D.    Lumbar

9.     Which one of the following may result from lack of progesterone hormone in a woman?

A.    Implantation may not occur.

B.     Miscarriage may occur.

C.     Menstartion may not occur.

D.    Ovulation may not occur.

10.  Which one of the following fruits is an example of a drupe?

A.    Avocado.

B.     Passion.

C.     Tomato.

D.    Orange.

11.   To identify a substance Y, a student performed the following experiment.

 

Test Observation
(i) Heated Y with Benedict's Solution Solution remained blue
(ii) heated Y with hydrochloric acid, cooled, added sodium hydrogen carbonate, benedict's solution, then heated again. solution turned from blue to orange.

From the observations, the most likely food substance in Y is

A.    Starch.

B.     Maltose

C.     Sucrose

D.    Glucose

12.  Which one of the following is true of both photosynthesis and respiration?

A.    Involve enzymes.

B.     Need light energy.

C.     Are exothermic.

D.    Occur in all living organisms.

13.  The reason why urine of a healthy person does not contain glucose is that

A.    The glomerulus is impermeable to glucose.

B.     Glucose is used for respiration before reaching the collecting duct.

C.     Glucose passes back into the blood stream.

D.    The kidney converts glucose to urea.

14.  Which one of the following reactions is likely to occur when a donor of blood group A gives blood to a recipient of blood group B?

A.    Antibodies a react with antigens B.

B.     Antigens B react with antibodies b.

C.     Antibodies b react with antigens A

D.    Antigens A react with antigens B.

15.  When round bean plants and long - selected bean plants were crossed, all the offspring were oval - seeded plants. This is an example of

A.    Complete dominance.

B.     Incomplete dominance.

C.     Mutation.

D.    Recessive genes.

16.  Which one of the following may not be used for classifying insects?

A.    Mouth parts.

B.     Feeding habits.

C.     Structure of legs.

D.    Type of eyes.

17.  Which one of the following is a possible sequence of plant succession on an undeveloped piece of land?

A.    Fungi - ferns - shrubs - trees.

B.     Fungi - mosses - shrubs - trees

C.     Mosses - trees - fungi - ferns.

D.    Mosses - herbs - shrubs - trees.

18.  The graph below shows the effect of varying pH on the time taken for an enzyme to break down food.

IMAGE

Which one of the following enzymes below could have given that response?

A.    Pepsin.

B.     Lipase.

C.     Salivary amylase.

D.    Trypsin.

19.  Which one of the following fins provides a major population force in a fish?

A.    Caudal.

B.     Pectoral.

C.     Dorsal.

D.    Pelvic.

20.  Which one of the following characteristics of respiratory surfaces is true of humans but not of insects?

A.    Highly vascularised.

B.     Have large surface area.

C.     Moist.

D.    Thin walled.

21.  The rapid elongation of the hypocotyls during germination causes

A.    Delay in emergence of photosynthetic leaves.

B.     Cotyledons to grow above the ground.

C.     Early emergence of photosynthetic leaves.

D.    Cotyledons to remain below the ground.

22.  Which one of the following blood vessels contains the lowest concentration of urea?

A.    Hepatic portal vein.

B.     Renal artery.

C.     Hepatic vein.

D.    Renal vein.

23.  Which one of the following is the correct response to increased carbon dioxide in human blood? The rate of

A.    Breathing is slowed.

B.     Heart beat is slowed down.

C.     Heart beat is increased.

D.    The pulse is slowed down.

24.  The tapeworm Taenia sodium has a primary and a secondary host. Which of the following are the primary and secondary hosts in that order?

A.    Pig and man.

B.     Cow and man.

C.     Man and cow.

D.    Man and pig.

25.  Which one of the following statements is not correct about photosynthesis?

A.    Water is required.

B.     Oxygen is a by-product.

C.     Sugar is a product.

D.    Energy is released.

26.   Figure 2 below shows the cycling of oxygen between the atmosphere and living cells.

IMAGE

Which process is represented by letter X?

A.    Excretion.

B.     Respiration.

C.     Decay.

D.    Photosynthesis.

because they have to generate higher pressure.

A.    Atria are thicker because they have to resist higher pressure.

B.     Ventricles are thicker because they have to generate higher pressure.

C.     Ventricles are thicker because they have to resist higher pressure.

27.  Which one of the following controls the rate of heart beat in a mammal?

A.    Cerebrum.

B.     Pituitary.

C.     Medulla oblongata.

D.    Cerebellum.

28.  Which one of the following events occurs during osmosis?

A.    Solute molecules move from more to less concentrated solution.

B.     Solvent molecules move from more to less concentrated solution.

C.     Solvent molecules move from less to more concentrated solutions.

D.    Solute molecules move from less to more concentrated solution.

29.  Which of the following is characteristic of a soil with low capillarity?

A.    Poor water retention.

B.     Poor drainage.

C.     Poor aeration.

D.    Small particles.

 

SECTION B

Answer all questions in this section. Answers must be written in the spaces provided.

30.  The graph below show the variation in the amount of sweat and urine with temperature in humans.

IMAGE

a)     How does the increase in temperature affect

(i)    Urine production?

(ii)   Sweat production?

b)    Explain your answers in (a) (i) and (ii) above.

(i) Explanation for (a) (i)...........................................................................

(ii) Explanation for (a) (ii).........................................................................

c)     State three conditions under which humans pass out concentrated urine.

(i) .............................................................................................................

(ii) ............................................................................................................

(iii) ............................................................................................................

d)    Apart from sweating, state three other body responses by mammals to overheating.

(i) ...........................................................................................................

(ii) ...........................................................................................................

(iii) ...........................................................................................................

31.  Figure 3 below is an experimental set up to investigate the conditions for photosynthesis. The plant is in light but had previously been kept in the dark overnight.

IMAGE

a)     Which condition is being investigated?

b)    Why

(i)     Was it necessary to keep the plant in the dark overnight?

(ii)    Is the leaf left attached to the plant?

c)     What is the purpose of sodium hydroxide in the flask?

d)    (i) How would you test for starch in the leaf after some time?

32.  The information below is on feeding relationships in an ecosystem.

Lizards feed on praying mantis, butterflies and herbivorous bugs. Praying mantis feed on butterflies and herbivorous bugs. Butterflies and herbivorous bugs feed on grass.

a)     Using a suitable method show the feeding relationship between

(i)    All the organisms.

(ii)   The praying mantis, herbivorous bug, lizards and grass.

b)    How would the population of the organisms in (a) (i) above is affected if the praying mantis were removed from the ecosystem?

c)     (i) State one group of important organisms that have not been included in the ecosystem.

(ii) Why are the organisms named in (c) (i) above important in an ecosystem?

33.  Figure 4 below shows a section through the human eye.

IMAGE

a)     Name the parts labelled A, B, C and D.

A ...............................................................................................

B .............................................................................................

C ..............................................................................................

D..............................................................................................

b)    What function is performed jointly by the parts A, B, C and D?

c)     Other than the joint function, state two other functions of the part labelled D.

d)    Give the state of parts A, B and C when the eye is viewing.

(i)    Near objects.

A ...............................................................................................

B ................................................................................................

C ................................................................................................

(ii)   Distant objects.

A .............................................................................................

B ............................................................................................

C ............................................................................................

e)     State two eye defects and how they are corrected.

(i) Defect.....................................................................................

Corrective measure .............................................................

(ii)  Defect ...................................................................................

Corrective measure ............................................................

 

SECTION C

Answer any two questions.

34.  a) State the dangers of a parasitic mode of life.

b) Describe how a tapeworm is adapted to its mode of life.

35.  a) Describe the digestion of proteins in a mammal.

b) Explain how the ileum is suited for its mammal.

36.  a) With the aid of well labelled diagrams explain the difference between hypogeal and epigeal germination.

b) Describe an experiment you would carry out to show that heat is liberated by germinating seeds.

37.  a) Explain why a skeleton is necessary in a mammalian body.

b) With the aid of diagrams describe how a human arm can bend and straighten.

 

 

Monday, 28 May 2012 09:07

BIOLOGY 2002

Written by B.K.Sharon

PAPER 1

THEORY

SECTION A

Answer all questions in this section. For each question select the most correct option and write the letter representing it in the box provided.

1.     Which of the following are characteristics of surfaces for gaseous exchange?

A.    Large surface area, thinness and moistness.

B.     Thinness, moistness and presence of fine blood vessels.

C.     Large surface area thinness and presence of arteries and veins.

D.    Thinness, moistness and presence of arteries and veins.

2.     Stunted plant growth, creamy yellow leaves and poor fruit development is caused by deficiency of

A.    Nitrogen and potassium.

B.     Nitrogen and phosphorus.

C.     Potassium and iron.

D.    Nitrogen and iron.

3.     Which one of the following dental formulate is that of a sheep?

A.    I0/2 C0/0 Pm3/3 M3/3

B.     I2/2 Pm2/2 M3/3

C.     I3/3 C0/0 Pm 3/3 M2/2

D.    I2/2 C1/1 Pm2/2 M3/3

4.     Enzymes differ from catalysts because enzymes

A.    Are required in small amounts.

B.     Respond to temperature changes.

C.     Are proteins in nature.

D.    Speed up reactions.

5.     When preparing to test for starch in a leaf, the leaf is boiled in alcohol in order to

A.    Burst chloroplasts.

B.     Remove coloured materials in the leaf.

C.     Quicken the reaction of starch with iodine.

D.    Soften the leaf.

6.     In which of the following animals does expired route from that of inspired air?

A.    Birds.

B.     Reptiles.

C.     Bony fish.

D.    Mammals.

7.     Which one of the following does not aid flight in birds?

A.    Pectoral muscles.

B.     Hollow bones.

C.     Down feathers.

D.    Quill feathers.

8.     Which one of the following sets of organisms belong to the same group?

A.    Butterfly, beetle and starfish.

B.     Crab, tape worm and liver fluke.

C.     Scorpion, mite and spider.

D.    Jelly fish, slug and sea urchin.

9.     Which one of the following explains the accumulation of lactic acid in muscles during vigorous activity?

A.    Carbohydrate is completely broken down.

B.     The oxygen supply to the muscles may not be enough.

C.     Much of the stored glycogen is converted into glucose.

D.    The blood vessels leading from the muscles are constricted.

10.  Bacteria that often live in their hosts where both partners cannot survive without the other are called

A.    Parasites.

B.     Symbionts

C.     Commensals.

D.    Saprophytes.

11.   In a plant tissue, water moved from cell A to cell B. this indicates that

A.    Cell A and cell B had the same osmotic potential.

B.     Cell A had a higher osmotic potential than cell B.

C.     Cell A had a lower osmotic potential than cell B.

D.    Cell A was older than cell B.

12.  Which of the following are the end products of lactose?

A.    Glucose and sucrose.

B.     Glucose and Galactose.

C.     Glucose and fructose.

D.    Fructose and Galactose.

17.  Which one of the following sets contains only characteristics of continuous variation?

A.    Tongue rolling, blood groups, skin color.

B.     Height, body weight, intelligence.

C.     Sex, hemophilia, height.

D.    Finger prints, intelligence, albinism.

18.  The following are sizes of different soil particles in millimeters.

P = 2.0 - 0.02.

Q = 0.2 - 0.02.

R = 0.02 - 0.002.

S = less than 0.002.

In which of the following soil particles would you expect the rise of water by capillarity to be highest?

A. P

B. Q

C. R

D. S

19.  Which one of the following methods can be used to estimate the population of butterflies in a flower garden?

A.    Direct count.

B.     Quadrant.

C.     Line transects.

D.    Capture release - recapture.

20.  Where in the mammalian skin is the melanin pigment found?

A.    Malphighian layer.

B.     Granular layer.

C.     Cornfield layer.

D.    Subcutaneous layer.

21.  Which one of the following organisms reproduce by budding?

A.    Yeast

B.     Amoeba

C.     Spirogyra.

D.    Mucor.

22.  What would happen to a plant tissue placed in a strong sugar solution? It

A.    Becomes longer and soft.

B.     Maintains the original length and texture.

C.     Becomes shorter and soft.

D.    Becomes shorter and hard.

23.  Figure 1 shows a leaf type

IMAGE

Which type of leaf is shown in the figure above?

A.    Compound bipinnate.

B.     Compound trifoliate.

C.     Compound pinnate.

D.    Compound palmate.

24.  Which one of the following is not a function of blood?

A.    Regulation of sugar level in the body.

B.     Healing of damaged parts of the body.

C.     Regulation of body temperature.

D.    Transportation of wastes.

25.   Figure 2 is a cross section of part of a plant.

IMAGE

From one of the following was the section obtained?

A.    Root of dicotyledonous plant.

B.     Stem of monocotyledonous plant.

C.     Root of monocotyledonous plant.

D.    Stem of dicotyledonous plant.

26.  What effect does light have on the distribution of auxin at the tip of a plant shoot?

A.    Causes equal distribution of auxin at the shoot tip.

B.     Has no effect on the distribution of auxin at the shoot tip.

C.     Concentrates more auxin on the dark side of the shoot tip.

D.    Causes auxin to concentrate more on the illuminated side of the shoot tip.

27.  Which one of the following is a modified root?

A.    Irish potato tuber.

B.     Cassava tuber.

C.     Rhizome.

D.    Corm.

28.  Which one of the following organs is responsible for removing excess amino acids from blood?

A.    Gall bladder.

B.     Kidney.

C.     Liver.

D.    Spleen.

29.  Which one of the following is the most common air pollutant?

A.    Dust.

B.     Fungicides.

C.     Herbicides.

D.    Smoke.

30.  In which part of the kidney Nephron does reabsorption of glucose occur?

A.    Proximal convoluted tubule.

B.     Distal convoluted tubule.

C.     Descending loop of Henley.

D.    Ascending loop of Henley.

 

SECTION B

Answer all questions in this section. Answer must be written in the spaces provided.

31.   a) What is an artery?

32.   Figure 3 shows the effect of unidirectional light on the growth of plant shoots. Study the figure and answer and answer the questions that follow.

IMAGE

Key

(i)     Intact coleoptiles,

(ii)    Coleoptiles with cut tip.

(iii)   Coleoptiles with tip covered with aluminum foil.

a)     Explain why each coleoptile appears as shown after 5 days.

i) ..............................................................................................

ii) ..............................................................................................

iii) ..............................................................................................

b)    What is the importance of the response shown in the diagram, to plants?

33.   a) (i) which  chromosomes are responsible for determining sex in humans?

(ii) Using appropriate symbols show how sex is determined in humans.

b) Red - green color blindness is a defect caused by a recessive gene carried on the X chromosome. What would be the phenotype of the offspring when a normal woman marries a color blind man? Show your working.

34.  a) State four ways in which a leaf is suited for photosynthesis.

b) State two ways in which food transported to growing regions is utilized by the plant.

(i) .........................................................................................................................

(ii) ........................................................................................................................

 

SECTION C

Answer any two questions.

35.  Using named examples, describe the methods of fruit and seed dispersal.

36.  a) Give three characteristics of enzymes.

b) Describe an experiment to show that enzymes activity is affected by temperature.

37.  a) Give effects of four air pollutants on living things.

b) Describe how human activities interfere with soil environment in Uganda.

38.  Describe an experiment that you would carry out in the laboratory to test for the presence of a non - reducing (complex) sugar in a solution of a food sample. In your description, state the use of each reagent used.

 

 

 

 

 

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