BIOLOGY PAPER 1 - 2019 LAINAKU JOINT MOCK EVALUATION EXAMINATION

1. Give the role of the following parts of microscope. (3marks)
   1. Mirror
   2. Diaphragm
   3. Coarse adjustment knob
2. 1. What three characteristics are used to divide the phylum arthropoda into classes? (3mks)
   2. The diagram below represents a certain plant species.
      
      
      1. State the class to which the plant belongs. (1 mark)
      2. State two differences between members of Gymnospermaphyta and Angiospermaphyta (2 marks)
         

         Gymnospermaphyta	Angiospermaphyta

         State one observable xerophytic characteristic seen in the diagram above.          (1mark)

3. The following specimen was collected by form two students during a nature walk.
   
   
   1. Name the tooth labeled M. (1 mark)
   2. Name the part labeled Q and state its role. (2 marks)
      Name:
      Role:
4. A solution of sugarcane was boiled with hydrochloric acid; sodium carbonate was added; cooled and benedict’s solution was added then boiled. An orange precipitate was formed.
   1. Why was the solution boiled with hydrochloric acid?         (1mark)
   2. Why was sodium carbonate added?             (1mark)
   3. Name the type of reaction that takes place when simple sugars combine to form complex sugar.                                                                                                 (1mark)
5. 1. Define the following terms as used in ecology. (2 marks)
      1. Biosphere
      2. Biomass
   2. Form three students wanted to estimate the population of grasshoppers in 8km² grass field near a school compound. They captured 72 grasshoppers and marked them before returning them back to the field. After three days they made another catch of grasshoppers. They collected 147 grasshoppers of which only 29 had marks.
      1. State why the second capture was done after three days. (1 mark)
      2. From the data, calculate the population size of grasshoppers in the grass field. (2 marks)
6. State the most suitable biological tool for collecting the following organisms:-
   1. A moth from a farm.                                     ( 1 mark)
   2. Ants from a tree trunk.                                                                         ( 1 mark)
7. The diagram below represents an organ from a finned bony fish. Study it and answer the question that follows
   
   
   1. Identify the organ illustrated above. (1mark)
   2. State three adaptations of the part labeled S to its functions.             (3 marks)
8. 1. State two characteristics that researchers select in breeding programs in plants
   2. In a maize the gene for purple colour is dominant to the gene for white colour. A pure breeding maize plant with purple grains was crossed with heterozygous plant. Using letter G to represent the gene for purple colour, work out the genotypic ratio of the offspring. (2 marks)
9. 1. Name the organelle where Kreb’s/ citric acid cycle take place in a cell. (1mark)
   2. In which organelle is each of the following found: (2mark)
      1. Lytic enzymes            
      2. Chromosomes
10. State the importance of osmo- regulation in organisms ( 2 marks)
11. Explain why unicellular organisms such as paramecium lack complex organs for gaseous exchange.                                                                                                       ( 2marks)
12. The diagram below represents a transverse section of a plant part. Study it and answer the questions that follow.
    
    
    1. Name the class in which the plant belongs.             ( 1mark)
    2. Give a reason for answer (a) above.                          ( 1mark)
    3. State one adaptation for the structures labeled X to their functions.             (1mark)
13. State the function of the following structures in the human ear.
    1. Semi – circular canals. ( 1mark)
    2. Eustachian tube. ( 1mark)
14. The diagram below shows the internal structure of a broad bean seed. Study it and answer the questions that follow.
    
    
    1. Name the part labeled B. (1 mark)
    2. Why is it important that the part labeled A develops first during germination? (2mark)
15. The diagram below represents a mammalian bone.
    
    
    1. Identify the bone             ( 1mark)
    2. Name the bones that articulate with this bone at points K and L             ( 2 marks)
16. The equation below represents a metabolic process that occurs in the mammalian liver.
    Amino Acids   =    Organic compound + Urea
    Name the process                                                                                            (1 mark)
17. The diagram below represents a set up that was used to investigate a certain process in a plant.
    
    
    1. State the process that was being investigated. (1 mark)
    2. Other than the factors shown, state two factors that would affect the process named in (a) above.                           ( 2 marks)
18. Give an example of the sex linked trait in humans located on
    Y – Chromosomes                                                                                                   (1mark)
    X – Chromosomes                                                                                                   (1 mark)
19. Outline two roles of active transport in human beings. ( 2 marks)
20. 1. Name the causative organism for amoebic dysentery. (1 mark)
    2. State three preventive measures of schistosomiasis in human beings    (3 marks)
21. Tom, a form two students set up the apparatus shown below to demonstrate the breathing mechanism in a mammal.
    
    
    1. What structure in a mammal is represented by each of the following? ( 2marks)
       1. Glass tube
       2. Rubber sheet 
    2. Explain what will happen to the balloons if the rubber is pulled down wards.
22. 1. What is adaptive radiation?                                                                ( 2marks)
    2. Explain why crossbreeding is important in animal breeding. (2 marks)
23. The diagram below shows a phenomenon which occurs during cell division.
    
    
    1. Identify the stage of cell division in which this phenomenon occurs.        (1 mark)
    2. State the importance of the phenomenon taking place in the part labeled B. (2 marks)
24. 1. State one advantage of double circulation over single circulation. ( 1mark)
    2. State two adaptations of blood capillaries to their functions. (2marks)
25. 1. Name a growth hormone that has inhibitory effects in plants.          ( 1mark)
    2. State two characteristics of meristematic cells. (2marks)
26. Write down two functions of exoskeleton.                                                 (2 marks)

MARKING SCHEME

1. 1. Reflect light from the source for the microscope specimen;
   2. Regulate amount of light entering the microscope/reaching the specimen;
   3. Move body up and down in order to obtain a rough focus of image/specimen; (3mks)

2. 1. number of body parts , number of jointed appendages, number of compound eyes , number of antennae.( mark the first three)( 3mks )
   2. 1. Coniferales; ref. with S at the end
      2. State the difference between members of Gymnospermaphyta and Atngiospermaphyta              (2 marks)
         

         Angiospermaphyta	Gymnospermaphyta
         1.      Seeds bone on flowers	Bear seeds on cones
         2.      Ploem has companion cells	Phloem lack companion cells
         3.      Seeds not enclosed in fruit wall (naked seeds)	Seeds enclosed in ovary

         the needle like leaves … 1(mk)
3. The following specimens were extracted from a newly discovered organism. 
   1. Name the tooth labeled M.             (1 mark)
      Incisor; ref plural & wrong spelling
   2. Name the part labeled Q and state its role. (2 marks)
      Name: Horny pad/pad of gum
      Role: Provides surface against which grass is pressed and cut by incisors.
4. 1. The solution was boiled with HCl to hydrolyze the non-reducing sugars to reducing sugar. (1mk)
   2. The sodium carbonate was used to neutralize the excess hydrochloric acid.
   3. Condensation
5. 1. 1. biosphere : the part of the earth and atmosphere inhabited by living organisms olso known as the Ecosphere. (1mk)
      2. Biomass: the total dry weight of living organisms at a particular trophic level/ per unit area. (1mk)
   2. 1. Allow the grasshoppers to mix freely with the rest of the population.
      2. calculation = = = 365)
6. 1. 1. sweep net
      2. pooter
7. 1. Gill/ Reject Gills
   2. highly vascularised for transportation of gases
   3. thin epithelium to reduce distance travelled by diffusing gases
      large surface area for gaseous exchange
8. 1. productivity
      Drought resistance
      Disease resistance …..
   2. check the crossing should be correct.GgX GG =(GG,GG,Gg,Gg)
      Check the calculations of the ratios’…..

9. 1. mitochondrion (reject. mitochondria )
   2. 1. lysosome; (1mk)
      2. Nucleus ;                                                                                            (1mk)
10. Maintains salt- water balance/osmotic pressure to optimum levels; in the body tissues /fluids;
    That is favourable to normal functioning of cells;

11. It has a large surface area exposed to its aquatic environment; gaseous exchange is therefore by (simple) diffusion across its membrane; (2mks)
12. 1. Dicotyledonae;   reject. dicot…. docotyledone                                                                  (1mk)
    2. Centrally placed star shaped Xylem with phloem (alternatively) between the arms of the Xylem;     
    3. Numerous/Elongated to increase surface area for absorption of water/minerals/both;
        - Thin walled for faster absorption of water/mineral salts/or both;
       - Numerous mitochondria to provide energy for absorption of mineral salts;
       Large sap vacuole to create high osmotic pressure;        Any one correct 1x1 =1mk
13. 1. Semi- circular canals-
       Maintenance of body balance and posture;                                             (1mk)
    2. Eustachain
       It equalizes air pressure in the outer and middle ear to prevent distortion of the ear drum/tympanic membrane;                                                    (1mk)

14. 1. Epicotyl;            (1mk)
    2. - It enables the seedling to be firmly anchored in the ground;
        - It enables the seedling to obtain water and mineral salts;                          (2mks)

15. 1. Femur                                                                                                            (1mk)
    2. 1. K – Pelvic girdle/ innominated born;                                                 (1mk)
          (Reject the fused bones);
       2. L – Tibia;
          Accept Tibia and fibula.
          Reject   Fibula and tibia.

16. Deamination;                                                                                                 (1mk)
17. 1. Photosynthesis;
    2. Carbon (IV) oxide concentration;     (the valency power correctly)
       Temperature;
        Amount of chlorophyll;           (b) is tied to (a) (Any two correct 1x2 =2mks)

18. Y - Chromosome – Tuft of hair from the pinna/ premature baldness;     (1mk)
    X – Chromosome – Colour blindness/Haemophilia;
    Duchenne muscular dystrophy; (1mk)
19. (It facilitates the) reabsorption of useful substances in the kidney tubules into the blood stream;
    (It facilitates the) absorption of digested food from the gut into the blood stream;
    (It helps in the) movement of waste products from body into the blood stream/excreation of waste productsfrom the body cells into the blood stream; 
    (Any first two correct 2x1 = 2mks)

20. 1. Entamoebahistolytica;     (rules of Binomial nomeclacture followed)   (1mk)
    2. 1. Proper (sanitary) disposal of faeces and urine/use of deep pit latrines/flash toilets for disposal of faeces and Urine;
       2. All drinking water boiled/chemically treated to kill the eggs/miracidia/cercariae;
       3. People should not bath/swim in water infested with snails;
       4. People should wear protective shoes/water proof shoes/gumboots when walking in waters infested with snails/swampy areas;
       5. Spray water infested with snails with molluscicides; (Any first three correct 3x1 = 3mks)
21. 1. 1. Trachea;   (1mk)
       2. Diaphragm; (1mk)                                                   Reject wrong spelling
    2. There will be an increase in volume and a decrease in pressure in the bell jar thereforeair will fill the balloons;/Air enters the balloons;/ ballons will inflate.                (Total 2mks)

22. 1. A situation where organisms have homologous structure/structures with common embryonic origin; which ismodified to perform different function; to adapt organism to different ecological niches/habitats/due toexploitation of different ecological niches/habitats;
    2. It involves mating different breeds of species; resulting to Hybrid vigour/the offspring are better adapted than their parents/Heterosis. (2mks)

23. 1. Prophase I ;(Reject wrong spelling/prophase 1/i)
    2. Recombination of genes; leading to variation;                                          (2mks)

24. 1. blood flows with higher pressure/ blood flows a longer distance per unit time(1 mk)
    2. single cell wall/ thin wall. Many / numerous and form a network (2mks)

25. 1. Abscisic acid; (reject wrong spelling/AbA)             (1mk)
    2. Thin walled; numerous mitochondria;
       -Dense cytoplasm;
       No vacuoles;
       Small in size; (any first two correct 2x1 = 2mks)

26. It protects the inner delicate tissues;
    It prevents dehydration or desiccation;
    Provide a surface for attachment of muscle; (which are essential for movement).
    (any first two correct 2x1 = 2mks)