Biology Paper 3 Questions, Answers and Confidential - Maranda Mock Examinations 2022

Instructions to candidates:

1. You are required to spend the first 15 minutes of the 1¾ hours allowed for this paper reading the whole paper carefully.

QUESTIONS

1. You are provided with Specimen K .Carefully cut a transverse section through specimen K using a scalpel provided.
   1.                    
      1. By observing one of the two halves of specimen K, Give two reasons to prove that specimen K has axile placentation (2marks)
      2. Squeeze some juice from specimen K into 100ml beaker provided and label it as juice K. Using a portion of juice K, carry out the food test using the reagents provided and complete the table below. (NB preserve the remaining portion of juice K for use in question 2 ) (8marks)
         

         Food substance	Procedure	Observation	Conclusion

      3. Name the deficiency disease that results from lack of the food substance present in juice K. (1mark)
      4. Highlight two symptoms of the disease named in (a) (iii) above (2marks)
   2. Put 2cm³ of liquid labeled C into a test tube. Draw some of the juice from specimen K into a dropper. Add 4 drops of the juice into the test tube with solution C and shake.
      1. State your observation. (1mark)
      2. State the part of the human body where the process demonstrated above occurs and the enzyme that carries out the process.
         Part of body... (1mark)
         Enzyme... (1mark)
      3. Which gland produces the enzyme stated in (a) (ii) above? (1mark)
2.                  
   1. Take a small amount of substance B provided and add to it 2cm3 of sodium hydrogen carbonate solution.
      1. State your observations (1mark)
      2. Which process in the body is illustrated above? (1mark)
      3. State the part of the body where the above process takes place (1mark)
      4. State two functions of substance B in the body (2marks)
      5. Name two diseases of the circulatory system caused by excess cholesterol in food. (2marks)
   2. Study the photographs below depicting plants growing in different habitats. Use them to answer the questions that follow.
      
      
      1. Identify the habitats in which they are found (2marks)
         Y
         Z
      2. State the significance of the following structures found in the specimens shown above. (2marks)
         R
         S
3.                
   1. Below are photographs of Venus flytrap (an insectivorous plant). Study them and answer the questions that follow.
      
      
      1. Name one major nutrient that is deficient in the soil where the above plant grows. (1mark)
      2. Name the type of response shown by photograph C (1mark)
      3. Describe how the above plant traps the insect (4marks)
   2. The photographs below are of the same mammalian vertebra showing two views of the same bone. Examine them carefully.
      
      
      1. Identify the vertebra.. (1mark)
      2. Name the region from which the vertebra is obtained. (1mark)
      3. Name the part marked X (1mark)
      4. State the function of part X (1mark)
   3. State the functional difference between a tendon and a ligament (1mark)
   4. Name the bone that articulate with this vertebra at the distal end (1mark) 

MARKING SCHEME

1.                    
   1.              
      1.                
         • Edges of the carpels fuse together to form a central placenta;
         • Ovary wall divides into multiple loculi/chambers;
      2.                
         

         Food substance	procedure	observation	conclusion
         Starch;	-To a little amount of juice K in a test tube add two drops of iodine solution;	-Brown color of iodine solution remains/persist;	Starch absent;
         Vitamin C;	-To a little amount of DCPIP in a test tube, add juice K drop wise as you shake;	-DCPIP decolorizes;	Vitamin C present;

      3. scurvy;
      4.                  
         • bleeding gums;
         • poor healing of wounds
         • anaemia
         • swelling of skin
         • reduced resistance to infections
   2.                        
      1. liquid C forms a solid particles /liquid C curdles;
      2. body part-stomach
         Enzyme-rennin           rej.renin
      3. gastric gland
2.                  
   1.                  
      1. broken down into small droplets;
      2. emulsification;
      3. duodenum;
      4. oxidized to release energy; 
         shock absobers on vital organs
         storage form of food;     
         source of metabolic water
      5. artheriosclerosis;
         thrombosis;
   2.              
      1. Y-aquatic/fresh water
         Z- teresterial
      2. R-minimizes rate of water loss / defense against browsers;
         S-store air for buoyancy;
3.                        
   1.                 
      1. nitrogen
      2. thigmo tropism /haptonasty;
      3. when the sensitive hairs on the leaves are touched (by the landing insect);the midrib loses turgidity rapidly; this makes the trap to spring inwards; hence closing the leaf; with the spines interlocking.
   2.                      
      1. axis;
      2. cervical/neck;
      3. odontoid process;
      4. articulate with the atlas vertebra to permits nodding of the head;
   3. tendon-attaches bone to muscles
      ligament- attaches bone to bone
   4. atlas vertebra

CONFIDENTIAL

Each candidate should be provided with the following:

1. Specimen K (Orange fruit)
2. About 3cm³ of substance B (olive oil)
3. About 3cm³ of liquid C (fresh cow milk)
4. About 2cm³ of 0.01% DCPIP (supplied with a dropper)
5. About 2cm³ of Iodine solution
6. About 2cm³ NaHC0³ solution (supplied with a dropper)
7. 6 test tubes in a test tube rack
8. Distilled water in a wash bottle
9. Scalpel
10. Two 10ml measuring cylinder
11. One 100ml beaker
12. 2 Labels
13. Two droppers