There are four organisms A, B, C and D. The organism A eats only the flesh of other animals as food. The organism B can eat grains, fruits and vegetables as well as meat and fish. The organism C can make the food itself from simple inorganic substances present in the environment by utilising sunlight energy. On the other hand, organism D eats only plants and their products as food.

1. Which organism is

1. Omnivore,
2. Herbivore,
3. Carnivore?

2. Which organism is an autotroph?
3. Which organism is/ are heterotroph (s)?
4. Which organism can be a producer?
5. Which organism is/ are consumer (s)?

Give one example each of organisms which could be like A, B, C and D.

Describe the mechanism of urine formation in human excretory system. Draw a labelled diagram to illustrate your answer.

There is a pair of bean-shaped organs P in the human body towards the back, just above the waist. A waste product Q formed by the decomposition of unused proteins in the liver is brought into organ P through blood by an artery R. The numerous tiny filters S present in organ P clean the dirty blood by removing the waste product Q. The clean blood goes into circulation through a vein T. The waste substance Q, other waste salts, and excess water form a yellowish liquid U which goes from organ P into a bag-like structure V through two tubes W. This liquid is then thrown out of the body through a tube X.

1. What is (i) organ P and (ii) waste substance Q?
2. Name (i) artery R, and (ii) vein T.
3. What are tiny filters S known as?
4. Name (i) liquid U, (ii) structure V, (iii) tubes W and (iv) tube X.

Water and dissolved minerals get into the root hair of a plant by a process called A and enter the conducting tissue B. The process C helps the water and dissolved minerals to move up through the tissue B in roots and stem, and reach the leaves of a plant. In the leaves food is made by a process D. This food is then transported to all the parts of a plant through tissue E. The process of distributing food made in the leaves to all the parts of the plants is called F.

1. What are (i) A, (ii) B, (iii) C, (iv) D, (v) E, and (vi) F?
2. Which tissue is made up of living cells: B or E?
3. Which tissue, B or E, contains sieve tubes?
4. Which tissue, B or E, contains tracheids?

Explain with a schematic representation the exchange of gases in tissues.

How do carbohydrates, proteins and fats get digested in human beings?

Draw a neat labelled diagram of the human excretory system.

Explain the process of nutrition in Amoeba.

Excretion is different in multi-cellular organisms as compared to unicellular organisms. How?

Why do we need a proper transportation system in plants?