Page 13 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Cell Theory

The cell theory was formulated by M.J.Schleiden and Theodor
Schwann summarizing the findings of various scientists. It puts
forward two main concepts -
1. The body of all organisms is made up of cells.
2. Cells are the structural and functional units of organisms.

What are the functions performed by cells?
Observe the illustration.

Resist foreign
particles

Functions of
cells

Release energy Synthesise
from nutrients biomolecules

The structure of a cell is complex enough to perform all these
functions. There are specific parts to perform each physiological
function inside the cell.
Observe different parts of a plant cell.

Nucleus
Cell membrane
Ribosome
Golgi complex
Endoplasmic
reticulum
Vacuole
Cytoplasm

Mitochondrion Chloroplast

Cell wall

Fig. 1.4
Plant cell
12 Basic Science VIII