Results

Patterns and processes of evolution. How evolution and natural selection are reflected in the similarities and differences of organisms. 

Introduction to cell theory--the idea that 1) all living things are made of one or more cells, 2) cells are the basic unit of life and 3) all cells come from other cells. Explore the roles that Hooke, Leeuwenhoek and others played in developing cell theory.

Hooke and Leeuwenhoek were two of the first scientists to use microscopes to study the microscopic world of cells. Hooke coined the term "cell" after observing the tiny compartments in cork, while Leeuwenhoek discovered a variety of living creatures in pond water, blood, and other samples. They contributed to the cell theory by suggesting that cells are the fundamental units of life and structure, and that all living things consist of one or more cells that originate from other cells by division. 

All living things are made up of cells, which is the smallest unit that can be said to be alive. An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular).

This video explains how to calculate the perimeter of various 2D shapes.

Introduction to the cell.

This is a short tutorial on how to define and measure the perimeter of shapes

By the end of this course you will be able to:

1. Define the terms perimeter and area
2. Find the perimeter of any polygon
3. Find the perimeter and area of a trapezium, parallelogram, rectangle and square
4. Find the area of a triangle
5. Find the perimeter and area of a circle

Even though molecules, proteins, viruses, and cells are all tiny, there are significant size differences between them. The diameter of a water molecule is roughly 0.28 nanometers. The diameter of the protein hemoglobin is roughly 5 nanometers. The diameter of the HIV virus is roughly 120 nanometers. A red blood cell is 6-8 micrometers.