The diagram of a grasshopper is one and a half of the real size of the grasshopper as drawn by a student. If the diagram is 3cm long a) Write down the formula of magnification. (1mk)

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b) Calculate the actual size of the grasshopper. (2mks)

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a) Which taxon has the largest number of members.(1mk)

b) Outline two physical features that make man and apes very different. (2mks) ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................

Study the apparatus illustrated below

a) Identify the apparatus......................................................................................(1mk)

b) What is the use of the mosquito net in the apparatus.......................................(1mk)

Give two disadvantages of sexual reproduction in mammals. (2mks) .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................

a) State what happens during the light stage of photosynthesis (2mks) ............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................

b) State the aspect of photosynthesis that is tested using a variegated leaf. (1mk)

State three structural differences between DNA and RNA (3mks) .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. ............................................................................................................................................................. ..............................................................................................................................................................

Sophia had a tooth ache, on inspection the mother realized that a hole had developed from above.

i) Identify the disease .................................................................................... (1mk)

ii) State two ways the disease would have been avoided. (2mks)

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State two examples of Biological control of population growth. (2mks) ............................................................................................................................................................ ............................................................................................................................................................. ............................................................................................................................................................. ..............................................................................................................................................................

Anaerobic respiration can be summarised diagrammatically as below

a) Explain briefly why the exoskeleton is disadvantageous to insects. (2mks) .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. ..............................................................................................................................................................

b) What is the role of intervertebral Discs in mammalian skeleton. (1mk) .............................................................................................................................................................. .............................................................................................................................................................

A piece of potato which is three centimetres long was placed in an Isotonic solution and did not change. a) What is an Isotonic solution. (1mk) ........................................................................................................................................................ ........................................................................................................................................................

b) Explain what would happen if the same piece of potato was placed in a hypotonic solution. (2mks) ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ .......................................................................................................................................................

. a) Nitrates is the form in which nitrogen is availed to plants. The process of breaking down nitrates to nitrites, ammonia and even nitrogen gas is known as (1mk)

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b) List two adaptations of emergent hydrophytes. (2mks)

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Below is an illustration of growth and developmental stages of a certain insect.

a) Give a name to the developmental cycle represented above. (1mk) ........................................................................................................................................................

b) Explain what takes place in stage W.

(1mk) ......................................................................................................................................................

. A group of Biology students picked an organism from the shores of the school dam. They observed and classified the organism as follows.

KINGDOM.......Animal

DIVISION........Arthropoda

CLASS............Chillopoda

i) State two mistakes the students made in their effort to classify (2mks) .................................................................................................................................................. .................................................................................................................................................. ..................................................................................................................................................

ii) State a characteristic that makes millipedes different from centipedes. (1mk) .................................................................................................................................................. ..................................................................................................................................................

a) Write down two types of evolutionary evidence that does not employ structural comparison. (2mks) ......................................................................................................................................................... ........................................................................................................................................................... ...........................................................................................................................................................
b) State the type of evolution where one basic structural form is modified to give rise to various different forms. (1mk)
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a) Define the term Homeostasis (1mk)

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b) Briefly explain how amoeba regulates the amount of water in the body when placed in distilled water. (2mks) ................................................................................................................................................ ............................................................................................................................................... ..............................................................................................................................................

Which organs are affected by the following diseases, Hepatitis and Candidiasis respectively. (2mks) ....................................................................................................................................................... ......................................................................................................................................................... ........................................................................................................................................................

. Heterostyly, is a condition where sometime the style may be longer or shorter than the filaments as illustrated belo

a) Of what benefit is each arrangement to a plant. (2mks)

.A.................................................................................................................................................... ........................................................................................................................................................ ...................................................................................................................................................... B..................................................................................................................................................... ........................................................................................................................................................ ....................................................................................................................................................

b) Define seed viability (1mk) ........................................................................................................................................................ .......................................................................................................................................................

State three biological importances of tropisms to plants. (3mks) ........................................................................................................................................................... ........................................................................................................................................................... ..............................................................................................................................................................

a) Which physiological process is investigated by using a potometer. (1mk) ...........................................................................................................................................................

b) Name two forces that maintains the process named in 20

(a) above. (3mks)

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List three ways in which non-woody stems acquire support. (3mks) .......................................................................................................................................................... .......................................................................................................................................................... ...........................................................................................................................................................

. a) Carbon (II) oxide is lethal if inhaled, what compound does it form in blood when inhaled.

............................................................................................................... (1mk)

b) Explain how the gas affects the process below


(2mks)
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Name three plant structures in which excretory products are stored and finally eliminated from plants. (3mks) ......................................................................................................................................................... ........................................................................................................................................................ .........................................................................................................................................................

a) Birds and Fish have a common structure that assists them in buoyancy Identify the structure

...................................................................................... (1mk)

b) A part from the structure named in

(a) above, state two other characteristics that are useful for flight in Aves. (2mks) .................................................................................................................................................. ............................................................................................................................................... .................................................................................................................................................. ..................................................................................................................................................

State two other gaseous exchange structures in plants besides stomata. (2mks) .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................

Most bones in mammals have processes or broad surfaces. Suggest the importance of those features. (3mks) .......................................................................................................................................................... .......................................................................................................................................................... ........................................................................................................................................................... .........................................................................................................................................................

i) Define a simple Reflex arc. (1mk)

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ii) Name any two neurones associated with a simple Reflex arc. (2mks) .................................................................................................................................................. ..................................................................................................................................................

. Define the following Genetic terms i) Gene linkage (1mk)

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ii) Phenotype (1mk)

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iii) None Disjunction (1mk)

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a) Name any two digestive enzymes that are produced in an inactive form. (2mks) ............................................................................................................................................................ ............................................................................................................................................................. .............................................................................................................................................................. ............................................................................................................................................................

b) Give a reason as to why the above named enzymes are produced in inactive form. (1mk) .................................................................................................................................................. ..................................................................................................................................................

. Growth in plants is restricted to specific region unlike in Animals.

a) What are the names of the growth tissues in plants. (2mks) ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................

b) Define growth (1mk)

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