Cell - Structure and Functions Class 8 Worksheet Science

Q.1. Name the organelle of a plant cell where photosynthesis takes place.

In plants, photosynthesis takes place in chloroplasts, which contain chlorophyll.

Q.2. What is the basic similarity among all the living organisms (plants and animals)?

All living things (plants and animals) are made from cells.

Q.3. What is a tissue?

A tissue is a group of similar cells performing a specific function.

Q.4. Which is the largest floating body generally in the center of a cell?

The nucleus is the largest floating body generally in the center of a cell.

Q.5. Name the outermost layer of an animal cell.

The cell membrane is the outermost layer of an animal cell.

Q.6. What is a gene? What is its function?

Gene is a unit of inheritance in living organisms. It controls the transfer of a hereditary characteristic from parents to offspring.

Q.7. What are unicellular organisms? Give two examples.

The single-celled organisms are called unicellular (uni: one; cellular: cell). Example: amoeba and paramecium.

Q.8. What is plastid? What is the name of green plastids present in plant cells?

Colored bodies called plastids are found in plant cells only. Green plastids containing chlorophyll are called chloroplasts.

Q.9. What is a cell wall? What is its function?

A cell wall is an additional covering over the cell membrane in plant cells. It gives shape and rigidity to these cells.

Q.10. Does the number of cells in an organism affect its functioning? Explain.

The number of cells is less in smaller organisms does not, in any way, affect the functioning of the organisms. A single-celled organism performs all the necessary functions that multicellular organisms perform. An organism with billions of cells begins life as a single cell which is the fertilized egg. The fertilized egg cell multiplies and the number of cells increases as development proceeds.

Q.11. Which part of the cell gives it shape?

Components of the cell are enclosed in a membrane. This membrane provides shape to the cells of plants and animals. A cell wall is an additional covering over the cell membrane in plant cells. It gives shape and rigidity to these cells. The bacterial cell also has a cell wall.

Q.12. What are the different shapes of cells?

Generally, cells are round, spherical, or elongated. Some cells are long and pointed at both ends. They exhibit a spindle shape. Cells sometimes are quite long. Some are branched like the nerve cell or a neuron.

Q.13. What are multicellular organisms? Give two examples.

Organisms made of more than one cell are called multicellular (multi: many; cellular: cell) organisms. Most of the plants and animals around us are multicellular organisms. Example: a mango tree, a deer, etc.

Q.14. What is a nuclear membrane? State its function.

The nucleus is separated from the cytoplasm by a membrane called the nuclear membrane. This membrane is also porous and allows the movement of materials between the cytoplasm and the inside of the nucleus.

Q.15. What is protoplasm?

The entire content of a living cell is known as protoplasm. It includes the cytoplasm and the nucleus. Protoplasm is called the living substance of the cell.