THE BASIC UNITS OF LIFE
Overview
A brief overview of the history of microscopy needs to be taught. This should include the progression from the use of lenses, light microscopy and then electron microscopy. The development of microscopy over the years has enabled people to view cells and then with the introduction of the electron microscope the structures within cells. All this led to the cell theory.
This section deals with the ultra-structure of cells, including cell wall, cell membrane, nucleus, cytoplasm, and various organelles such as chloroplast, mitochondria, ER, vacuoles, Golgi bodies and centrosomes.
Transport across membranes is also covered briefly. Learners will need to understand the movement of molecules by diffusion, osmosis and active transport.
Key Concepts:
|
"In the year of 1657 I discovered very small living creatures in rain water." — Antonie van Leeuwenhoek, the Father of Microbiology, on discovering cells. Together with Robert Hooke's discoveries, van Leeuwenhoek's findings laid the foundations of microbiology.
The previous chapter discussed the various organic molecules that make up living organisms. In this chapter we will look at the cellular level of organisation of living things.
atom\(\rightarrow\)molecule\(\rightarrow\)cell\(\rightarrow\)tissue\(\rightarrow\)organ\(\rightarrow\)system\(\rightarrow\)organism\(\rightarrow\)ecosystem