Biology Paper 1 Questions and Answers - MECS Cluster Joint Mock Exam

QUESTIONS

1. A form one girl observed a bird laying eggs in a nest which later hatched into chicks. Name two characteristics of living things that she concluded from the
2. Name the stage in meiosis where chromosomes number is reduced by a half (1mark)
3. State two characteristics of organisms that belong to the same species (2marks)
4.      
   1. Live specimens should always be returned to their habitats whenever possible. What is the biological importance of this practice? (1mark)
   2. Why is a dissecting pin important in biological experiments? (1mark)
5. Mutations form basis for variations. Name the type of mutation that cause the following human disorders
   
   1. Albinism (2marks)
   2. Down syndrome
6.      
   1. During a field trip a plant that had flowers drew the attention of a student. Name the division of the plant.
   2. Students observed an animal with the following features
      
      • Dorsoventrally flattened body
      • One pair of legs per segment
      • Poison claws on the head
        
        1. Name the class to which the animal belongs. (1mark)
        2. State the mode of feeding of the animal (1mark)
7. Study the process below and answer the questions that follow
   Glucose → process P → Pyruvic acid + Energy.
   
   1. Name the process P (1mark)
   2. Name the part of a cell in which the process named in (a) above occurs (1mark)
8. Account for the following observations.
   
   1. When fish is taken out of water it dies (2marks)
   2. The palisade cells are closely packed together (1mark)
9.      
   1. Give the significance of the following features of the red blood cells.
      Being biconcave in shape. (1mark)
   2. Lacking mitochondria ( 1mark)
10. A person fell from the third floor of a building and had part of his brain damaged. Name the part of the brain damaged if the person suffers from the following
    
    1. Loss of speech (1mark)
    2. Inability to regulate body temperature (1mark)
    3. Lack of balance (1mark)
11. In body cells of all organisms chromosomes occur in pairs. Members of each pair have a characteristic length and shape.
    
    1. What is the scientific name of such a chromosome pair? (1mark)
    2. What name is given to a cell that contains one member of each pair of chromosomes? (1mark)
    3. Name the part in humans where meiosis takes place (2marks)
12. Small birds like the European robin puff up (swell up) their feathers during winter. Explain the significance of the behavioral response. (3marks)
13. Name the most appropriate tool that biology students can use for collecting (2marks)
    
    1. Crawling animals
    2. Stinging organisms
14. During a microscopy class a student was unable to see the field of view. State two possible adjustments she needed to make to ensure that the field of view became visible. (2marks)
15. Name the apparatures used to measure the following abiotic factors. (2marks)
    
    1. Penetration of light in water
    2. Light intensity
16. A lion is an exclusive carnivore. State two dental adaptations it has to its mode of feeding (2marks)
17.      
    1. State an example of structures in animals whose development demonstrates adaptive radiation (1mark)
    2. Treatment of malaria is still a challenge in the world despite the invention of many antimalarial drugs. Explain. (3marks)
18. Name two processes that brings about the translocation of manufactured food (2marks)
19. Name the disorder of the blood described by the following symptoms (2 marks)
    
    1. Inability of the blood to clot.
    2. Crescent shaped red blood cells with abnormal haemoglobin.
20. Explain how a nerve impulse is passed across a synapse (3marks)
21.      
    1. A large crocodile can survive on 20kg meat for a year. A small sized lion cannot. Explain (3marks)
    2. Name the part of the body that helps in insulation in the following: (2marks)
       
       1. Birds
       2. Mammals
22. Name two types of valves in the heart. (2 marks)
23. Sometimes when one stands up very quickly after a long period of sitting, she may feel faint or dizzy. Explain. (2 marks)
24. The diagram below represents a bone of a mammal
    
    
    1. Identify the bone. (1 mark)
    2. Name the part marked X. (1 mark)
    3. Name the bone that articulates at the part labelled F. (1 mark)
    4. State two ways in which the bone is adapted to its function. (2 marks)
25.      
    1. Under which of the following magnifications would one see a larger part of the specimen X 40 or X 500? Give a reason. (2 marks)
    2. State how magnification is worked out in a light microscope (1mark)
26. State two characteristics of mammals that are not externally visible (2marks)
27. State three uses of digested food in the bodies of animals (3 marks)
28. Which cell organelle is present in large numbers in cells that produce Insulin? Give a reason for your answer (2marks)
29. Give three advantages of fossil records (3marks)
30. What is the significance of diffusion to plant pollination? (1mark)
31.      
    1. Explain why it is not advisable to put a patient on a drip of distilled water for rehydration (3marks)
    2. Name the physiological process by which water molecules move from one cell to the other (1mark)

MARKING SCHEME

1.      
   1. Reproduction
   2. Growth and development
   3. locomotion/movement
2. At anaphase I rej anaphase alone
3. They are hereditary distinct
   They give rise to fertile offspring’s
4.    
   1. Maintaining the ecological balance
   2. used to hold specimens into the dissecting board during dissection
5.        
   1. Gene substitution; rej substitution alone
   2. (Chromosomal) non-disjunction
6.      
   1. Spermaphyta/ spermatophyta (1marks)
   2.    
      1. Chilopoda rej chilopoda
      2. Carnivorous
7.      
   1. Glycolysis
   2. Cytoplasm
8.      
   1. The gills filaments clump together; reducing the surface area for gaseous exchange; this causes suffocation of the fish to suffocate; any two
   2. To ensure maximum trapping of light
9.      
   1. Increase the surface area for packaging of more haemoglobin hence maximum absorption of gases/to squeeze through the narrow lumen of blood capillaries
   2. Ensure the red blood cells do not utilize the oxygen they carry accept allow more space for haemoglobin packing rej packaging
10.        
    1. Cerebrum
    2. Hypothalamus
    3. Cerebellum
11.      
    1. Homologous chromosomes
    2. Haploid
    3. Testis/ testes
       Ovary/ ovaries
12. To reduce heat loss; since the feathers trap more air; that acts as insulator;against heat loss/ that is a poor conductor of heat.
13.        
    1. Pitfall trap; rej pitfall alone
    2. Pair of forceps; rej forceps alone
       Acc pair of tweezers
14. Adjust the mirror;
    Ensure that the diaphragm is fully open;
    Ensure that the objective lens is clicked into position with the eye piece lens;
15.      
    1. Seechi disc
    2. Photographic light meter
16. Long conical/ curved canines to hold/ kill/ tear the prey;
    ( has premolars specialized into) carnassials teeth with smooth sides and sharp edges to slice through flesh and crush bones;
17.      
    1. Pentadactyl limbs; the feet of birds; the beak of birds; mark any one correct
    2. Some parasites mutate; to acquire the gene for resistance; to the drugs used. (The ones without the gene are eliminated by the drugs) The ones with the resistant gene acquire a selective advantage to survive to maturity; and their offspring inherit the genes; A new population of resistant parasites is hence developed; OWTTE max 3mks
18. Active transport
    diffusion
    cytoplasmic streaming
19.      
    1. Haemophilia
    2. Sickle cell anaemia.
20. Impulse arriving at the pre-synaptic knob; causes synaptic vesicles containing (transmitter substance) Ace tylcholine to move and attach onto pre-synaptic membrane; burst to release Acetylcholine; which diffuses across the synapse to the post-synaptic membrane where it causes depolarization;of the membrane max 3 marks
21.      
    1. Crocodile is poikilothermic; so no energy lost to environment; while lion is homoiothermic; so heat energy constantly lost to environment;
    2.      
       1. Feathers;
       2. Wool/ fur/ body hair/ adipose tissue;
22. Atrio-ventricular valves/Cuspid valves;
    Semi – lunar valves;
23. The rapid change in posture alters the body’s blood distribution; causing a temporary Lack of blood in the brain;
24.         
    1. Scapula; rej scapular
    2. Spine;
    3. Humerus;Rej Humerous
    4. Has the glenoid cavity which articulates with the head of the humerus ;
       Has a spine for attachment of muscles;
       Is broad/has a large surface area for the attachment of the shoulder muscles;
       Has acromion and metacromion for attachment of muscle (Any two)
25.        
    1. X40; it is a lower magnification thus giving a wider view;
    2. Magnification=Eye piece lens magnification X Objective lens magnification;
26. Presence of sweat glands;
    Double circulatory system;
    Lungs for gaseous exchange; any other correct answer
27. Growth;
    Repair of worn out tissues;
    Protection;
    Production of energy;
28. Golgi bodies/apparatus; for the transportation of the secretions/Insulin;
29. Show extinction of certain organisms (at certain geological age);
    Show transitional forms between groups of organisms;
    Show direct evidence of the type of organisms that existed during a given geological period;
    Show progressive increase in complexity from simple organisms to complex organisms;
    Show that different classes of organisms arose at different times;
30. The insects that carry out pollination are attracted by the scent from the flowers; (this may cause them to land on the flowers and transfer the pollen grains leading to pollination)
31.      
    1. Distilled water is hypotonic compared to the (patient’s) internal body fluids; by osmosis; the cells would take in distilled water, swell and burst/haemolyse(leading to death/more damage);
    2. Osmosis;