Concept: Cells and Tissues
- Cells are the structural and functional units of the living body.
- Tissues originate from cells. A tissue constitutes a group of cells.
- Cells are of two types: (i) Animal cells and (ii) Plant cells.
|Parts of an animal cell||Structure and functions|
|1. Cell Membrane||It is the thin lining that covers the cell.|
|2. Cytoplasm||A fluid-like substance inside the cell.|
|3. Nucleus||It is located at the centre of the cell and controls all activities of the cell.|
|4. Mitochondria||Numerous mitochondria are present in the cytoplasm. It produces energy to keep the cell active.|
|5. Ribosome||Ribosomes are present in large numbers in the cytoplasm. They help in protein synthesis.|
|Parts of a plant cell||Structure and functions|
|1. Cell Wall||It is the outermost covering of the plant cell. It is made up of waxy materials and protects the cell from external stress.|
|2. Cell Membrane||It is the thin lining that covers the cell.|
|3. Cytoplasm||It is the fluid-filled matrix that is present inside the cell.|
|4. Vacuoles||These are closed fluid-filled pouch-like structures present inside the cytoplasm.|
|5. Nucleus||It is located either in the centre of the cell or may shift to the sides. The nucleus controls all activities of the cell.|
|6. Plastid||Plastids are present in the cytoplasm of all plant cells. They store food and contain colourful pigments. Green plastids are called chloroplasts.|
|Plant cells also have ribosomes and mitochondria in the cytoplasm.|
Characteristics of tissues:
- Various types of tissues are present in the human body.
- A tissue is made with a pack of cells that originate from the same source, i.e., structurally, they are similar and perform the same function.
Epithelial tissue, which makes our skin; muscle tissue which makes our body muscles.
Matrix: A jelly-like substance that is present inside all cells.
Membrane: A thin layer that forms the outer lining of a cell.
Did You Know?
Millions of cells together make a tissue. Several tissues together make an organ, and several organs together make our body.