Question

7.Assertion : In the daytime, CO2 generated during respiration is used up for
photosynthesis.
Reason : There is no CO2 release during the day.

8. Assertion : Lungs always contain a residual volume of air.
Reason : It provides sufficient time for oxygen to be absorbed and for carbon dioxide to be released.
9.Assertion : Energy is used during the process of respiration.
Reason : Respiration stores energy in the form of ATP.

2 marks
1.Where do plants get each of the raw materials required for photosynthesis?
2.What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
3.“If there were no algae there would be no fish in the sea”. Comment.
4.Write the role of saliva in the buccal cavity.
5.Write the functions of: (a) HCL (b) Mucus (c) Pepsin
6.Enumerate the enzymes secreted by pancreas and their role.
7.How are lungs designed to maximize the exchange of gases?

Answer 1

Answer:

7.a is false and r is true and r is correct reason for assertion

Answer 2

Assertion (A) In the day time, CO 2 generated during respiration is used up for photosynthesis.

Reason (R) There is no CO 2 release during day.

• Both A and R are true and R is the correct explanation of A
• This is because carbon dioxide generated during daytime is used by the plants in the process of photosynthesis.
• While using CO2 in the presence of sunlight, they produce glucose and oxygen thus counter balancing CO2 release.  
• So, the correct option is 'Consume it in photosynthesis in day time, CO2produced during respiration is used by the plants in photosynthesis.
• So, CO2 is not released into the environment.
• The oxygen produced during photosynthesis, is released into air through stomata.
• At night, when there is no photosynthesis, no oxygen is released.