Question

4. The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm.
(b) mitochondria.
(c) chloroplast.
(d) nucleus.
5. How are fats digested in our bodies? Where does this process take place?
6. What is the role of saliva in the digestion of food?
7. What are the necessary conditions for autotrophic nutrition and what are its by-
products?
8. What are the differences between aerobic and anaerobic respiration? Name some
organisms that use the anaerobic mode of respiration.
9. How are the alveoli designed to maximise the exchange of gases?
10. What would be the consequences of a deficiency of haemoglobin in our bodies?
11. Describe double circulation of blood in human beings. Why is it necessary?
12. What are the differences between the transport of materials in xylem and phloem?
13. Compare the functioning of alveoli in the lungs and nephrons in the kidneys with
respect to their structure and functioning.
Processes​

Answer 1

4. Mitochondria
6. Saliva contains salivary amylase or ptyalin which helps in digestion of starch
8. Aerobic takes place in the presence of oxygen while anaerobic takes place in the absence of oxygen example yeast
9. Alveolar membrane is very thin for quick diffusion of gases and it is richly supplied with blood vessels for efficient transport and exchange of gases
10. Not enough transport of oxygen according to the body’s needs
12. Xylem transports water and minerals phloem transports food materials prepared by the leaves

Answer 2

12.

Xylem tissue helps in the transport of water and minerals. Phloem tissue helps in the transport of food. Water is transported upwards from roots to all other plant parts. ... Transport of food in phloem requires energy in the form of ATP.