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The diagram below represents three types of neurons found in a mammalian body.
(a) Name the neurons X, Y and Z
(b) Name the chemical substance responsible for the transmission of an impulse across the gap labelled W.
(c) State two functions of the part labelled M.
(d) In which part of the spinal cord is neurone Y located?
(e) Using arrows indicate on the diagrams the direction followed by nerve impulse leading to a response.
Date posted:
September 16, 2019
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Below is a diagram of a plant a form three student collected while carrying out an ecological study
a) With reasons identify the division into which the students classified the plant.
b) (i) Name the structure that produces spores in this plant.
(ii) State two differences between the plant division above and that of the division spermatophyta.
c) Give two distinguishing features of class Amphibia
Date posted:
September 16, 2019
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Below is a diagram of a structure found in Eukaryotic cells. Study it and answer the questions that follow
a) Identify the structure
b) State two functions of the structure
c) i) Name one organelle found in animal cells but absent in plant cells
ii) State one function of the organelle you have named in(c) i) above
Date posted:
September 16, 2019
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Some form three students took a germinating maize grain and placed it in a starch paste in a petri dish and put the Petri dish in a water bath maintained at 30oC. After 48 hours the starch paste was irrigated with iodine solution .The area around the maize grain changed to the colour of iodine solution while the rest turned blue –black.
(a) Account for the observation
(b) Why was the Petri dish put in a water bath maintained at 30oC?
Date posted:
September 16, 2019
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The diagram below represents a simple endocrine feedback mechanism in a human male.
(a) Name the hormone labeled X
(b) State two differences that may be observed between a normal male and one who is incapable of producing hormone labeled Y
Date posted:
September 16, 2019
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What are the functions of the odontoid process found on the axis bone of the cervical vertebra?
Date posted:
September 16, 2019
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Active yeast cells were added to a dilute sugar solution in a container. The mixture was kept in a warm room. After a few hours bubbles of gas were observed escaping from the mixture.
(a) Write an equation to represent the chemical reaction above.
(b) What is the economic importance of this type of chemical reaction in industry?
Date posted:
September 16, 2019
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In which part of the spinal cord is the cell body of the motor neurone found?.
Date posted:
September 16, 2019
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State the role of the swim bladder in a fish.
Date posted:
September 16, 2019
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Name the division of the Kingdom plantae with the following spore producing bodies.
(i) Sori
(ii) Capsule
Date posted:
September 16, 2019
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A small amount of chemical M was put on one side of maize celeoptiles. After some days, it was noted that the celeoptiles curved away from the side to which the chemical was applied.
(a) Suggest the possible identity of chemical substance M
(b) Explain how this chemical might have caused the celeoptiles to curve.
Date posted:
September 16, 2019
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In a blood test, a few drops of anti-B serum were added to two samples of blood. It was noted that agglutination occurred.What were the possible blood groups of the two blood samples?
Date posted:
September 16, 2019
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Industrial wastes may contain metabolic pollutants. State how such pollutants may indirectly reach and accumulate in the human body if the wastes were dumped into rivers.
Date posted:
September 16, 2019
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The apparatus whose diagram is given below can be used to demonstrate results of a physiological process that occurs in a mammal. To use the apparatus, the experiment places his mouth at the point marked X and breaths in and out gently.
a. State the observations in the boiling tube when the experimenter
i) Breaths in:
Boiling tube, A
Boiling tube, B
b) Breaths out:
Boiling tube, A
Boiling tube, B
c. What conclusions can you draw from the results of this experiment
d. What is the purpose of the boiling tube A?
Date posted:
September 16, 2019
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A patient whose blood group is A died shortly after receiving blood from a person of blood group B. Explain the possible cause of the death of the patient.
Date posted:
September 16, 2019
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Construct a step in a dichotomous key using two animals one with two pairs of legs and the other with four pairs of legs.
Date posted:
September 16, 2019
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The diagram below shows the difference in growth response to varying hormone concentration by root and shoot
What is the effect of increasing auxin concentration on:
i) Roots
ii) Shoot
Date posted:
September 16, 2019
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State two ways in which human body is naturally protected against harmful bacteria.
Date posted:
September 16, 2019
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Complete the table below on mineral nutrition in plants.
Date posted:
September 16, 2019
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State one major importance of convergent evolution to living organisms.
Date posted:
September 16, 2019
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Figure 1 represents a bat wing. Figure 2 a whale paddle and figure 3 an insect wing. Study the diagrams and answer the questions that follow.
(i) In figure 1, identify bones: H and E
(ii) Name the type of joint formed by bones H and E.
(iii) Identify the type of structures shown above and the type of evolution.
Structures:
Type of evolution:
Date posted:
September 16, 2019
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The figure below shows feet of various birds. Study the diagram and answer the questions that follow.
(a) Giving a reason, state the type of food eaten by Bird E.
Food eaten:
Reason:
(b) Name the habitat of bird D and give a reason for your answer.
Habitat:
Reason:
(c) Identify the type of structures shown by the feet above and give a reason for your answer.
Type of structure:
Reason:
(d) State the type of evolution shown by the structures.
Date posted:
September 16, 2019
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You are provided with plant specimens below.
A) Construct a dichotomous key using the features given below in order.
(i) Leaf type
(ii) Leaf venation
(iii) Leaf colour
(iv) Leaf margin
(v) Number of leaflets
(vi) Attachment of leaflets
1) (a) Leaf simple ……………………………………………. go to 2
(b) …………………………………………………………………………….
2) (a) ……………………………………………………………………………
(b) Leaf with network venation …………………………… go to 4
3) (a) ……………………………………………………………………………
(b)…………………………………………………………………………….
4) (a) ……………………………………………………………………………
(b)…………………………………………………………………………….
5) (a) ……………………………………………………………………………
(b)…………………………………………………………………………….
6) (a) ……………………………………………………………………………
(b)…………………………………………………………………………….
B) Using the steps followed, identify the plant specimens provided.
Date posted:
September 16, 2019
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An experiment was carried out to determine the growth rates of bamboo and a variety of maize plants in two adjacent plots.The average height and average dry weight of plants from the two populations were determined over a period of twenty weeks. The data is as shown in the table below.
(a) Between which two weeks did the greatest increase in weight occur in:
(i) Bamboo plants:
(ii) Maize plants:
(b) (i) Which of the two types of plants had a higher productivity by the end of the experiment?
(ii) Give a reason for your answer in (b) (i) above.
(c) Between weeks 14 and 18, the average height of the maize plants remained constant while average dry weight increased.Explain this observation.
(d) Suggest how the change in the average dry weight bamboo and maize plants would have been at week 22 if the experiment was continued.
(e) Why was it appropriate for this experiment to use:
(i) Dry weight instead of fresh weight.
(ii) Weight and height.
(f) Describe how the average height and weight of the plants were determined in this experiment.
(i) Average height.
(ii) Average dry weight.
(g) Give a reason why secondary thickening does not occur in bamboo and maize plants.
Date posted:
September 16, 2019
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During an ecology, students collected and marked 40 ants and then released them. After 2 days, the students captured another 100 ants, 40 of which had been marked previously.
(i) How many ants were there in the compound? Show your working.
(ii) Give two assumptions of this method in sampling animal population.
Date posted:
September 16, 2019
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Study the food web below representing a certain ecosystem and use it to answer the questions that follow.
(i) Write down a food chain in which the vulture is a tertiary consumer.
(ii) What would be the effect of introducing gazelles and termites into the ecosystem?
Date posted:
September 16, 2019
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The equation below represents a certain physiological process. Study it and answer the questions below.
(i) Name the above process.
(ii) Give two reasons for question (i) above.
(iii) Calculate the respiratory quotient of the compound that was as the substrate.
(iv) Identify the substrate being respired in the above equation.
(v) State one importance of this process to living organisms.
(vi) Name the organelle where the above process takes place in animal cells.
Date posted:
September 16, 2019
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A man with normal skin colour got married to a woman with normal skin colour. They gave birth to three children; one of them an albino.
(a) Identify the probable genotype of the parents using letter (A) for normal gene and (a) for defective gene.
Man:
Woman:
(b) Using a genetic cross; show the genotypes of the offspring.
(c) Give the phenotypic ratio of the offsprings.
Date posted:
September 16, 2019
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Use the graph below to answer the questions that follow.
(a) Calculate the difference in nitrate concentration between the highest and lowest.
(b) How can increase in nitrate concentration in the river lead to death of fish?
(c) Suggest one possible sources of nitrate that lead to the pollution in a river.
Date posted:
September 16, 2019
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The diagram below shows a seed of a certain plant.
(a) Name the likely agent of dispersal.
(b) Give a reason for your answer.
Date posted:
September 16, 2019