2015
1.
(a) what features do insects have in
common?
(8 marks)
(b)
how are birds adapted to flight?
(12 marks)
(c)
state the economic importance of birds
(5 marks)
Total (25 marks)
2.
(a)
what is photosynthesis ?
(4 marks)
(b)
state the difference between photosynthesis and respiration (14 marks)
(c)
how is photosynthesis important to living organisms? (7
marks)
Total (25 marks)
3.
(a)
Define the following terms:
I.
Active
transport
II.
Osmosis
(2,
3 marks)
(b)
Describe an experiment to demonstrate osmosis in a living tissue. (10 marks)
(c) How does a molecule of water from the soil
get to the leaf of a plant? (10
marks)
Total (25 marks)
4.
(a)
Define the terms :
i.
Eutrophication
ii.
Pollination
iii.
Ecosystem
(4,4,5 marks)
(b) How would changes in temperature affect
plants? (12
marks)
Total (25 marks)
5. (a) make a large
labeled diagram of the mammalian skin
(b) state the functions
of the parts you have labeled
(c) briefly compare the
mammalian skin and the epidermis of plants
total (25 marks)
6
(a) Define the following terms:
i.
Homozygous
ii.
Haploid(b)
when Mendel crossed pure breading red flowers pea plant with pure breading
flowered plant, all the pea members of the F1 generation had pink
flowers.Using appropriate symbols and diagrams show the possible genotype and
phenotype if:
i.
The
F1 individuals are allowed to self pollinate.
ii.
An
F1 individual is crossed with a white flowered parent (20 marks)Total (25 marks)
7. (a) Draw a labeled diagram of the
longitudinal section of a mammalian heart. (10 marks)
(b) Describe how the mammalian heart
function.
(15 marks)
Total (25 marks)
8. (a) Define the terms:
i.
Predation
ii.
Saprophytism. (2,3 marks)
(b)How
will you carry out a simple test to show the presence in germinating seeds of:
i.
A
reducing sugar.
ii.
Protein.
(5,5 marks)
(c) The table below shows the population size of both predators and
preys within a certain community.
The time was recorded in weeks
|
Time
(weeks) |
4 |
7 |
15 |
20 |
26 |
36 |
|
Number
of predators |
220 |
190 |
330 |
220 |
130 |
490 |
|
Number
of preys |
340 |
440 |
200 |
360 |
640 |
370 |
i.
Plot
the two curves with time on the horizontal axis and population on the vertical
axis. (5 marks)
ii.
Determine
population ofpreys and predators at week
10 and week 20. ( 4 marks)
iii.
Determine
the first time when the population of preys will be equal to that of
predators. (1 mark)
Total (25 marks)
2016
1.
(a) List the characteristics
common to insects.
(7marks) (b)the life cycle of a house fly.
(11marks)
(c) how are insects beneficial in nature.
(7marks) Ttotal (25marks)
2.
(a) Give a balance equation that summarizes aerobic respiration. (5marks) (b) Describe an experiment to
demonstrate that germinating seeds produce heat. (13marks) (c)
Give the differences between aerobic and anaerobic respiration. (7marks)
Total (25marks)
3.
(a) Give an account of the circulation of water in
nature.
(15marks) (b) Describe an experiment to demonstrate Osmosis in living
tissue.
(10marks) Total (25 marks)
4. (a) what is genetic engineering?
(3marks) (b) Give and account of the importance of
genetic engineering to man.
(10marks) (c) how is light important to
(i) plants
(ii)Animals?
(12marks) Total
(25marks)
SECTON B
5.
(a)How is the leaf of plants suited for photosynthesis?
(15marks) (b) how would you
demonstrate that light is necessary for photosynthesis?
(10marks)Total (25 marks)
6.
(a) Define the term
excretion.
(4marks) (b) list the excretory
products in plants and their method of elimination. (8marks) (c) list the excretory organs in man and
state what each eliminates.
(8marks) (d) how is
osmoregulation carried out in a fresh water amoeba?
(5marks) Total (25 marks)
7.
(a) Define the following terms:
(i)
Genetics
(ii) Genotype (iii)
Heterozygous
(iv)
Fertilization (8marks) (b)A gardener
crossed a white flowered plant and a red flowered plant and the resulting F1
plants had pink flowered plants among themselves, the next generation of plants
(F2) had 22 red, 80 pink and 20 white flowers . using suitable genetic symbols
and diagrams, describe the genetics of the above crosses as fully as
possible. (17
marks)Total (25 marks)
8. (a)Define the following terms:
(i) Stimulus
(ii) Tropism
(iii)
Reflex action.
(11 marks) (b) Describe what happens when the hand accidentally touches
a hot object. (10
marks) (c) How are tropisms important to
plants?
(4 marks) Total (25 marks).
2017
1. (a) state the characteristics of
living organisms.
(7marks) (b)Describe reproduction
in amoeba under favorite conditions. (2marks) (c) How does an amoeba feeds?
(6 marks) (d)Describe what will
happen if a marine water amoeba is put in fresh water. (5
marks) Total (20 marks)
2. (a) state the composition of blood in
mammals.
(2 marks) (b) how is blood
important in mammals?
(10 marks) (c) how is transport
carried out in plants? (8 marks) Total
(20 marks)
3. (a) Define the term irritability.
(4marks) (b) Draw a large labeled diagram of the mammalian skin. (10 marks) (c) Explain what happens when a shoot is
illuminated from one direction. (6marks)Total (20 marks)
4. (a) Draw large labeled diagram of a
longitudinal section of the mammalian kidney. (6 marks) (b) the table show the quantities of various substances
in plasma and urine.
|
Substances |
Plasma |
Urine |
|
Glucose |
200g |
Trace |
|
Sodium salt |
600g |
6g |
|
Urea |
60g |
35g |
|
Water |
180litres |
1.2litres |
Account for the difference in the quantities of the various
substances in plasma and urine.
(9 marks) (c) carbon
dioxide is an excretory product. How is the percentage composition of carbon
dioxide kept constant in the atmosphere?
(5marks) Total (20 marks)
5.
Define the following terms as used in environmental biology: (i) Environment.
(ii)
pollution.
(5,4 marks) (b)Differentiate
between a food chain and a food web.
(6 marks) (c) state the uses of
food in living organisms
(5marks) Total (20 marks).
2018
1.
(a)
State the charateristics of living things organisms. (7
marks)
(b) Describe reproduction in Amoeba
under favourable conditions. (2 marks)
(c) How does an amoeba feed? (6
marks)
(d)
Desdcribe what will happen if a marine Amoeba is put in fresh water.
2.
(a)
State the composition of blood in mammals.
(b) how is blood important in
mammals?
(c)
How is transport carried out in plants?
(Total=20marks)
3.
(a)
Define the term irritation.
(b) Draw a large lebelled diagram of
the mammalian skin.
(c) Explain
what happens when a shoot is illuminated from a direction.
(Total=20marks)
4.
(a)
Draw a large labelled diagram of the longitudinal section of the mammalian
kidney.
(b) the table bellow shows the
quantity of various substances in blood plasma and urine.
|
Substance |
Plasma |
Urine |
|
Glucose |
200g |
Trace |
|
Sodium salt |
600g |
6g |
|
Urea |
60g |
35g |
|
Water |
180litres |
1.2litres |
Account for the difference in
quantity of the various substances in plasma and urine.
(9marks)
(c) carbon dioxide is an excretory,
how is the percentage of carbon dioxide kept constant in the atmosphere ? (5marks)
(Total=20marks)
5.
(a)
Define the following terms as used in environmental biology: (5,4 marks)
I.
Environment.
II.
Pollution.
(b) Differentiate between food chain
and food web.
(6marks)
(c) State the uses of food in living
organisms. (5marks)
(Total=20marks)
2019
1. (a) State the composition of the
following.
I.
Proteins
II.
Fats
III.
Cabohydrates
(b)
how do you test for
I.
The
presence of reducing sugar in germinating maize seed/
II.
The
presence of fats in meat?
III.
The
presence of proteins in meat?
(TOTAL=20 marks)
2.
(a) draw a large and well labelled diagram of an insect polinated flower.
(b) Distinguish between pollination
and fertilization
(c)
How is the
I.
Coconut
fruit
II.
Cotton
seed
III.
Mango
fruit
Adapted to their various methods of dipersal?
(TOTAL+20 marks)
3.
(a) State the functions of human skeleton.
(b)
make a large lebelled diagram ofa typical synovial joint.
(c) what is
I.
Long-sightedness?
II.
Astimatism?
(TOTAL= 20marks)
4. (a) Define the following terms:
I.
Monohybrid
cross
II.
Mutation
III.
Homozygous
(b)
State the causes of mutations.
(c) in
a certain variety of squirels, the fur colour is either grey or black. When a
pure breeding black squirel is crossed with a pure breeding grey squirels, all
the offsprings produced had grey fur. When this offsprings where allowed to
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