Biology Paper 2 Questions - Kapsabet Boys Post Mock 2023 Exams

INSTRUCTIONS

• This paper consists of two sections: A and B.
• Answer ALL the questions in section A
•  In section B answer question 6 (compulsory) and either question 7 or question 8 i after question 8
• Candidates should answer the questions in English.

QUESTIONS

SECTION A. 40 MARKS
Answer all the Questions in this section.

1.  
   1.  
      1. Name a carbohydrate secreted in the duodenum. (1 mark)
      2. Name the organ that secretes the carbohydrate you named in (a) (i) above. (1 mark)
   2. State the function of carbohydrate (1 mark)
   3. Name three characteristics of organic catalysts found in the gut. (3 marks)
   4. State two ways in which food physically digested along the alimentary canal (2 marks)
2. Proteins are present in a balanced diet. They are broken down into amino acid, the body cannot store amino acids, and so any excess amino acids are metabolized as shown below.
   
   Excess amino acids
   Carbon (IV) oxide + water + energy Removal from the body
   1. Name the process S and T, stating the organ in which each occurs.
      

      Process	Name	Organ
      S
      T

   2. Describe how urea is transported to the site of removal from the body. (2 marks)
   3. State the type of respiration shown, giving a reason to explain your answer (2 marks)
3. The diagram below indicates an organism that grows under shaded places with damp conditions. Study it and answer the questions that follow.
   
   
   1. Name the division to which the specimen belongs. (1 mark) 
   2. Name and state the functions of the parts labelled Q, R and S. (6 marks)
      Q
      R
      S
   3. Name the two body forms of the organism in its alternation of generation. (2 marks)
4. Two bacteria strains were introduced in a culture in a petri dish at the same time and in equal numbers. The graph below represents their population during the first days.Study the graph and answer the questions that follow:
   
   
   1.  
      1. Which species has a better competitive ability? (1 mark)
      2. Give a reason for your answer. (1 mark) 
   2.  Account for the shape of the curve for species A between.
      1. One day and three days. (2 marks) 
      2. Three days and seven days (2 marks) 
   3.  A natural predator for species A was introduced into the ecosystem with a reason. State how population of each species would be affected. (3 marks)
5.  
   1. What is meant by genetically modified organism. (1 mark)
   2. Njoki is an albino. Her husband Mwenda has normal skin colour. Two of their children have normal skin colour while two are albinos.
      1. Give the genotypes of Njoki and Mwenda. (2 marks)
      2. Illustrate the cross between the two parents. (4 marks) 
      3. Give the phenotypic ratio of offsprings. (1 mark)

SECTION B
Do question 6 and either 7 or 8

6.  In an experiment, a plant was exposed to different light intensities and a range of carbon(IV)oxide concentration in a greenhouse. Rate of photosynthesis was then determined using the products formed. The product was measured in mg-sec(s).
   
   
   1. Plot a graph of rate of photosynthesis against carbon(iv)oxide concentration (7marks)
      
   2.  
      1. Using the graph, determine the optimum range of light intensity in bright light (1mark)
      2.  The amount of carbon(IV)oxide in the atmospheric air is about 0.03%. What was the rate of
         photosynthesis at this concentration in dim light? (1mark) 
   3. Account for the shape of the graph in bright light. (4marks)
   4. Suggest the factors which was limiting the rate of photosynthesis between 0.12 and 0.20% carbon(IV)oxide in:
      1. Dim light (2marks)
      2. Bright light (2marks)
   5. State three ways in which palisade mesophyll cells are adapted for photosynthesis. (3marks)
7. Describe the structure and function of the heart. (20marks)
   1. External structure and function (b) Internal structure and function
8.  
   1. What are the adaptations of Xerophytes to their habitat. (10marks)
   2. Discuss the role of enzymes in human digestion. (10marks)