Learn Class 8 Science - Cell

What is a cell? What is it made of? You will get all things in detail.

About Cell

• Robert Hooke gave the concept of the cell in 1665.
• The word 'cell' refers to the structural unit ultimately that forms a living organism. Whether an animal or a plant, all things constitute a cell.

Types of Cell:

1. Unicellular cells: The cells consist of a single unit. For example, Parecemium, amoeba.
2. Multicellular cells: The cell consists of many units. For example, Plants, Human beings.
3. Prokaryotic cells: The cells in which there is no nuclear membrane. For example, Blue-green algae bacteria.
4. Eukaryotic cells: The cells have specific nuclear membranes. For example, Blue-green algae bacteria.

Parts of Cell

Cell membrane

• It is the one that gives shape to the nucleus & cytoplasm.
• Porous in nature.
• The thick outer layer is known as the 'cell membrane.'

Nucleus

• Aspherical component.
• Present in 'centre of the cell.'
• The thread-like structure 'chromosomes.'

Cytoplasm

• Jelly-like structure.
• Present between 'nucleus' and 'cell membrane.'
• Other components are called 'organelles.'
• LIKE: Mitochondria, Golgi body, Vacuole.

Nuclear membrane:

• Separated from 'cytoplasm' from the porous membrane.
• Transport substances i.e. between 'nucleus' & 'cytoplasm'.

Nucleolus:

• Small spherical bodies.
• A part of the nucleus.