The diagram shows a vertical section through the heart.

What are the functions of the numbered blood vessels?

Sumay studied about blood circulation in humans. He wanted to observe the flow of blood and was about to cut his finger a bit. He suddenly stopped realizing that this could be fatal. Read the above passage and answer the following questions.

(i) Why is the color of blood red?

(ii) Why does unclotted blood comes out from site of injury when platelets are present in the body?

(iii) Low count of which blood cells can make us vulnerable to infections?

(iv) What values do you think Sumay have?

The diagram represents a part of human circulatory system. Where is the blood pressure highest?

What is the correct route for blood flow in a human?

What may happen if a young plant is dug up and re-planted in another place?