Science questions in short. [3 marks ]

The finger-like projection of varying lengths protruding out of the body of Amoeba, is called pseudopodia. These projections appear and disappear as Amoeba moves or feeds. Thus, the function of pseudopodia is to facilitates movement and help in capturing food.

Differences between a plant cell and animal cell:

Plant cell	Animal cell
A plant cell has a cell wall around its cell membrane. Blue-green algae cell.	An animal cell does not have a cell wall around it.
Plastids are present.	Plastids are absent.
A single large vacuole is present.	Vacuoles either are absent or if present, they are smaller in size.

Most of cells are extremely small and cannot seen with naked eye, hence cells could not be observed and studied for thousands of years.

The muscle cells are responsible for movement in our body by contracting and relaxing.

Cytoplasm is a jelly-like substance present between the cell membrane and the nucleus. Cytoplasm contains many specialised cell organelles. Each of these organelles performs a specific function for the cell. Cytoplasm contains a number of minute living structure known as cell organelles. Each of these organelles performs a specific function for the cell. Most of the chemical reactions which are necessary to keep cell alive take place in the cytoplasm.

Plastids are major organelles found only in plant cells. The green coloured plastids present in plant cells, are called chloroplast. It contains photosynthetic pigment called chlorophyll which helps in the synthesis of food.

A tissue is a group of similar cells performing a specific function.
Examples: Epithelial tissue, muscle tissue.

Mitochondria is the site of cellular respiration or oxidation of food in a cell. It uses glucose and oxygen to produce energy. Hence, it is knowns as “Powerhouse of the cell”.