2. Cells: The basic unit of life

1. Core Content

Molecular Make-Up

Cells are mostly made up of proteins, carbohydrates, lipids, nucleic acids and water.

Brief overview of the history of microscopy: from lens and light microscopes and to electron microscopes. How these instruments enabled people to see cells and then structures within cells which led to cell theory. (Briefly revise Grade 9 work on the cell.)

Cell Structure and Function: The Roles of Organelles

• cell wall - support structure in plant cells only;

• cell membrane - fluid mosaic model, boundaries and transport: movement across membranes: diffusion, osmosis and active transport;

• nucleus, chromatin material, nuclear membrane, nucleopores, nucleolus: the control centre, heredity;

• cytoplasm - storage and circulation of materials;

• mitochondria - release energy during cell respiration;

• ribosomes - protein synthesis;

• endoplasmic reticulum (rough and smooth) - transport systems;

• Golgi body - assembles secretions;

• plastids - production and storage of food and pigments; and

• vacuole, lysosomes, vesicles - storage, digestion and osmoregulation.

Relate structure and location of organelles to their functions.

(This is an introduction; some organelle functions will be explored in more detail in other sections.)

Cells differ in size, shape and structure in order to carry out specialised functions [link to tissues].

The differences between plant and animal cells (link to Grade 9).

5. Informal Assessments