BIOLOGY PAPER 1 - KCSE 2019 MOCK EXAMINATION - KAKAMEGA

1. Ascaris lumbricaoides is an example of an endoparasite. The name Ascaris refer to (1mk)
2. State the function of cristae in mitochedrion (1mk)
3. An experiment was set up as shown below. Use it to answer the following questions
   
   The set up was left for 30 minutes.
   1. State the expected results (2mks)
   2. Explain the observation above (2mks)
4. Photosynthesis take place in two stages . Name the part of the chloroplast cohere
   1.  
      1. Light stage occurs (1mk)
      2. Dark state occurs (1mk)
   2. Use the equation below to answer the following question
      Co₂ + H₂0 C₆H₁₂O₆ + 0₂ + ATP
      Identify process K and L (2mks)
5.  
   1. Define the following terms (3mks)
      1. Mastication
      2. Peristalysis
      3. Churning
   2. Explain why pepsin is produced in form of pepsinogen (1mk)
6.  
   1. State the role of the following plant vessels
      1. Xylem (1mk)
      2. Phloem (1mk)
   2.  
      1. From which plant organ was the section obtained (1mk)
      2. Give two reasons for your answer in (a) above (2mks)
         
   3. Name the parts labelled J, K, and l (3mks)
   4. State two functions of the part labelled M (2mks)
7. State one difference between open and closed circulatory system (1mk)
8. Differentiate between serum and sebum (2mks)

9. State the function of vitamin K and calcium ions in blood clotting (2mks)
10. The chart below shows a feeding relationship in a certain ecosystem
    
    
    1. Construct two food chains ending with a tertiary consumer in each case (2mks)
    2. Which organism has the largest variety of predators in the food web   (1mks)
    3. Name secondary consumers in the food web (2mks)
11.  
    1.  
       1. State the melodic stage where crossing over occurs (1mk)
       2. What is the significance of crossing over (1mk)
    2.  
       1. Explain why pregnancy persists even when ovaries are removed after the fourth month of pregnancy (2mks)
       2. Why do pregnant women excrete less urea (2mks)
12. Suggest the types of germination exhibited by the seedling above (1mks)
    
    State 3 roles of part C (3mks)
13. Describe the discontinuous growth among members of class insect (2mks)
14.  
    1. Describe the adaptations of the guard cells to opening and closing of stomata (2mks)
    2. State two theories that explain the opening and closing of stomata (2mks)
    3. State two gaseous exchange structures in plants (2mks)
15.  
    1. Draw and label the structure of a gill (3mks)
    2. Explain the counter current follow system across the gills (2mks)
16. Name two categories of anaerobes (2mks)
17. The equation below shows an oxidation reaction of food substances
    5 C₅₁H₉₈O₆ + 145O₂ →102 CO₂ + 98 H₂0 + energy
    1. Determine respiratory quotient of the oxidation of food substance (2mks)
    2. Identify the food substance (
18. GlucoseGlycogen (2mks)
    Name A and B
19. The figure below show a portion of nucleic acid
    C – U – G – C
    1. Name the nucleic acid (1mk)
    2. Give a reason (1mk)
20.  
    1. What are analogous structures (1mk)
    2. State two examples of analogous structures (2mks)
21. In mice the allele for black fur is dominat to the allele for brown fur.
    What percentage offspring would have brown fur from a cross between hetero zygous black mice and brown mice. Show your working. Use letter B to represent the allele for black colour (4mks)                                                    
22. Significance of the following practices during preparation of temporary slide (2mks)
    1. Staining.
    2. Cutting thin section
23. State the Causitive agent of typhoid (1mk)
24. Other than using quadrant method gives one methods of estimating population of grass (1mk)

MARKING SCHEME

1. Generic name/Genus
2. Site for attachment of respiratory enzymes
3.  
   1. Visking tubing swell/turgid
   2. Water molecules more into the visking tubing by osmosis
4.  
   1.  
      1. Granna            
      2. Stroma
   2. K- Photosynthesis
      L- Respiration
5.  
   1.  
      1. Mostication- crushing of food by teeth in the mouth
      2. Peristalysis – movement of food through oesophogus by aid of contraction and relaxation of muscles.
      3. Churning - Mixing of food in the stomach
   2. To prevent it from digesting cells that produces it.
6.  
   1. Xylem – Transportation of water & mineral salts
      Phloem – Transportation of manufactured food
   2. Root
      Root hairs
      Absence of pith

8. Serum – plasma witout blood proteins
   Sebum- substance released by skin that it keep it moist & flexible
9.  
   1. Vit K – Formation of prothrombiu
   2. C_a²⁺ conversion of thromboplastiun to plastin
10.  
    1. Grass                 mice                 snakes                   Hawks
       Grass                 mice                 snakes                   Domestic cats
    2. Mice
    3. Lizard, Snakes, Domestic cats
11.  
    1.  
       1. Pophase 1
       2. Causes variation.
    2.  
       1. The placenta takes over the role of the hormone production
       2. Most amino acids are used to formation of new tissues of the foetus
12.  
    1.  
       1. Epigeal
       2. – Storage of food
    2.  
       1. Protection of phunule & radicle
       2. Photosynthesic role during early stages of germination

13. Growth occurs immediately after monthly and stops when the hard exoskeleton forms again
14.  
    1.  
       1. Chloroplasts presence
          Thin outer and thick inner layer
       2. Starch sugar interconversion theory
          Photosynthetic theory
          Pottasium ion theory
    2. Stomata
       Lenticells
       Pneumatophores
15.  
    1. Water flows in an opposite direction in relation to the flow of blood
       
    2. This increases conc gradient of O₂ & CO₂
16. Obligate
    Facultative
17.  
    1. 102
       145 = 0.703
    2. Lipid
18. A- lusulin
    B- Glucagon

19. Ribonucleic acid ( RNA)
    Presence of Uracil
20.  
    1. Structures with different origin but modified to perform same function
    2. Mark any relevant examples
21.  
    
    50%

22. Make structure more clear
    Allow penetration of light
    Salmonella typhi