br Home » End of term 1 biology questions for cambridge IGCSE year 10

End of term 1 biology questions for cambridge IGCSE year 10

1. A. State the atoms that make up the following chemicals of life. [10]

1. Carbohydrate   …………..    ………..     ……………

2. Proteins            …………..    ………..    ……………   ……………

3. Fats                   …………..    ………..    ……………

B.  Describe the structure of a DNA molecule [3]

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

C.  Complete the table below to show the food being tested using the chemicals below. [5]

Chemical Food being tested
Iodine  
Benedict solution  
Biurete  
ethanol  
DCPIP  

D. State any 2 roles of water in the body [2]

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

2. A. define the following terms

1. Enzymes [2] …………………………………………………………………………………………………………………………………………………………………………………………………………

2. catalyst [1] …………………………………………………………………………………………………………………………………………………………………………………………………………

B. Describe how an enzyme works using the terms:- active site, enzyme-substrate complex, substrate and product.[ a diagram is acceptable] [5]

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

c. enzymes are said to be specific. Explain why enzyme amylase only works on starch and can not work on anything else. [3]

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

d. describe the effect of the following on enzymes. Remember to state effect of low, optimum and high.

1. Temperature  [3]

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

2.pH  [3]

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

3. a. Define the term photosynthesis [2]

…………………………………………………………………………………………………………………………………………………………………………………………………………

b. State the balanced chemical equation for photosynthesis[2]

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

C. State any 3 things that must be there for photosynthesis to take place [3]

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

d. The diagram below shows the structure of a leaf. Name any 6 parts that you can remember. [6]