Page 4 - e book prim 611

Delta Modern Language Schools Unit 1 concept 1
Science department
Grade 6
1st term 2024- 2025

The cell

It is the building unit of living organism's body that carries out all its own vital
activities.
Cells are found only in the bodies of living organisms.
Most cells can't be seen by naked eye, we can see them with microscope.
The length of common animal cells and plant cells ranges between 0.1 mm and
0.005 mm.
Some cells are very large such as unfertilized bird egg that contains only one big cell.
Bacteria is a living organism that its body consists of one cell only with length less than
0.005 mm.
Living organisms grow and reproduce as a result of increasing the number of the cells.

► Characteristics of cells:

1- All cells have a cell membrane
2- Not all cells have a cell wall (plant cell has a cell wall, but animal cell doesn't have).

3- Not all cells have a nucleus (Red blood cell doesn’t have).
4-The cells of one living organism aren't identical.

Muscle cell

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