The kidneys in human beings are a part of the system for

1. nutrition
2. respiration
3. excretion
4. transpiration

The xylem in plants are responsible for

1.  transport of water
2. transport of food
3. transport of amino acids
4. transport of oxygen

The autotrophic mode of nutrition requires

(a) carbon dioxide and water

(b) chlorophyll

(c) sunlight

(d) all of the above

The breakdown of pyruvate to give carbon dioxide, water and energy takes place in

(a) Cytoplasm

(b) Mitochondria

(c) Chloroplast

(d) Nucleus

How are fats digested in our bodies? Where does this process takes place?

What is the role of saliva in food digestion?

What are the necessary conditions for autotrophic nutrition and what are its by-products?

What is the difference between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.

How are the alveoli designed to maximize the exchange of gases?

What would be the consequences of a deficiency of haemoglobin in our bodies?

Describe double circulation of blood in human beings. Why is it necessary?

What are the differences between the transport of materials in xylem and phloem?

Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.