Science Question Answer (5 Marks)

An Ameoba cell can change its shape and a white blood cell in human blood can also changing its shapes. The difference between an Amoeba cell and a white blood cell is that the Amoeba cell is a full-fledged organism which is capable of independent existence. While white blood cell is only a cell of human blood which is not a full-fledged organism and hence cannot exist independently. White blood cells can exist only inside the blood.

Chloroplasts are the green coloured plastids present in the cytoplasm of plant cells. They possess photosynthetic pigment called chlorophyll. Chlorophyll absorbs energy from the sunlight during the process of photosynthesis. In the process of photosynthesis, green plants make their own food in the presence of sunlight and chlorophyll with the help of inorganic substances like carbon dioxide and water. Thus, chloroplast help in the synthesis of food by green plants.

Plant organs	Anlmai organs
Leaf	Brain
Roots	Lungs
Stem	Kidneys
Flower	Heart

1. (i) The part P is Chloroplasts Chloroplasts are the food producers in plant cells and they are not present in animal cells because animal cells do not make their own food.

(ii) The part Q is Cell wall The cell wall is absent in the animal cells because they don't need cell walls. The main purpose of a cell wall is to provide stability and stiffness to the cell. And it is made up of cellulose.

2. (i) The part R is Chlorophyll Chlorophyll is the green pigment present in the leaves.

(ii) The part S is Cellulose Cellulose is a fiber and wood, cotton, etc. all contain cellulose.

Chromosomes are thread-like structures usually present in the nucleus that become visible only during cell divisions.
The function of chromosomes is to transfer the characters from parents to the off springs through the genes located on them.

The function of nerve cell: The nerve cell receives and transfers messages, thereby helping to control and coordinate the working of different parts of the body.

1. Heart - It pumps blood throughout the body.
2. Brain - It controls the activities of other parts of the body.
3. Roots - These help in absorption of water and minerals.
4. Leaves - These are responsible for synthesis of food.

Prokaryotic cells	Eukaryotic cells
Bacterium cell.	Amoeba cell.
Blue-green algae cell.	Human cheek cell.
	onion peel cell.