Resultaten

These three short online lessons discuss asteroids, comets and meteors.

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).

Introduction to the cell.

Other objects in the solar system are discussed in this online textbook viz. asteroids, meteorites, comets and dwarf planets.

This video explains the theorem of Pythagoras.

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.

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

• Identify different types of triangles.
• Investigate the relationship between the sides of a right-angled triangle to develop the Theorem of Pythagoras.
• Use the Theorem of Pythagoras to find missing lengths in right angled triangles.

Outcomes

In this course you will learn about: 

1. The relationship between the sides of a right-angled triangle.
2. Using the Theorem of Pythagoras to find missing lengths in a right angled triangles. 

In this video you will learn how to use the Pythagoras theorem.