Skip to page content

The Cell — Part 1: Cell theory, boundaries and the nucleus and organelles

Beta

Lesson

The Cell: A Unit of Life

Part 1 — what living things are made of, how a cell is wrapped, and what works inside it.

In this lesson you will

State the main points of the cell theory and distinguish protoplasm from cytoplasm
Compare the cell wall and the cell membrane
State the functions of the nucleus, nucleolus, mitochondria, endoplasmic reticulum, ribosomes and Golgi bodies

Concept

The cell theory

Table of the three main points of the cell theory
Point of the cell theory	What it means
All organisms are made of cells	One cell or many cells; no living thing is without them
The cell is the unit of structure and function	It is the smallest part that carries out the activities of life
New cells come from existing cells	Cells divide; they do not appear from non-living matter

Concept

Protoplasm and cytoplasm

Table distinguishing protoplasm, cytoplasm and nucleoplasm
Term	What it includes
Protoplasm	All the living matter of a cell: cytoplasm and nucleus together
Cytoplasm	The jelly-like part between the cell membrane and the nucleus; holds the organelles
Nucleoplasm	The protoplasm inside the nucleus