How are oxygen and carbon-dioxide exchanged in our body during respiration?

Suggest a suitable reason for the heart having four separate chambers.

1. Draw a sectional view of the human heart and label on it, Aorta, Right Ventricle and Pulmonary Veins.
2. State the functions of the following components of transport system:

1. Blood.
2. Lymph.

How does food prepared by leaves is utilized by roots? Explain.

Give the steps involved in photosynthesis.

If a person holds his breath after expiration for about 25sec, would there be occurrence of any exchange of respiratory gases in the lungs during this period? Explain.

Draw a labelled diagram of the human respiratory system.

Explain the process of breathing in man.

1. Mention any two components of blood.
2. Trace the movement of oxygenated blood in the body.
3. Write the function of valves present in between atria and ventricles.
4. Write one structural difference between the composition of artery and veins.

Explain the mechanism of photosynthesis.