A major portion of the carbohydrates produced by plants is stored in different parts of the plant (storage organs). Explain the mechanism by which this stored food is made available when different organs need it for growth.

There are various muscles present in the human digestive system known as sphincters. Two examples of those are given below:

1. Pyloric sphincter- at the junction of the stomach and small intestine.

2. Anal sphincter- at the anus.

Give ONE most likely consequence of malfunctioning of each of these sphincters?

The diagram shows a vertical section through the heart.

What are the functions of the numbered blood vessels?

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

The diagram shows part of the human gas exchange system.

What are W, X, Y and Z?

The below diagram shows the respiratory system of human beings.

Identify the correct function of the part labelled as 'X'.