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.

Learning Videos for 8th Grade Science - Cell

Cell Sample Questions for Class 8

Question 1

The produces energy in the cell.
A. mitochondrion
B. nucleus
C. vacuole

Question 2

The gives plants their green color.
A. nucleus
B. chromosome
C. chloroplast

Question 3

The negatively charged particles in an atom that orbit around the nucleus are called .
A. protons
B. neutrons
C. electrons

Question 4

Which letter on the diagram best represents when melting occurs?
A. A
B. B
C. C
D. E

Question 5

Both plant and animal cells have a cell wall.
A. True
B. False