Displaying 1 - 7 of 7 Resources

Cell theory

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. 

Subject and Topic
Form 1
Biology
Cell structure and organisation
Concept of cells
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2015
Creator/Author
Sal Khan
Keyword
Cells

Cells and organisms

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).

Subject and Topic
Form 1
Biology
Cell structure and organisation
Concept of cells
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2022
Creator/Author
Khan Academy
Keyword
Cells

Introduction to the cell

Introduction to the cell.

Subject and Topic
Form 1
Biology
Cell structure and organisation
Concept of cells
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2017
Creator/Author
Sal Khan
Keyword
Cells

pH Scale

Outcomes:

  • Determine if a liquid is acidic, basic, or neutral
  • Place acids or bases in relative order
  • Describe on a molecular scale, with illustrations, how the water equilibrium varies with pH
  • Determine concentration of hydroxide, hydronium and water at a given pH
  • Relate liquid color to pH
  • Predict (qualitatively and quantitatively) how dilution and volume will affect the pH and concentration of hydroxide, hydronium and water
Subject and Topic
Form 1
Biology
Introduction to biology
The biology laboratory
Resource Type
Simulatie
Language
English
Publisher
pHET Interactive Simulations
Publication Date
No date
Creator/Author
Yuen-ying Carpenter (lead)
Keyword
pH
Dilution
Concentration
Acids
Bases

Scale of cells

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.

Subject and Topic
Form 1
Biology
Cell structure and organisation
Concept of cells
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2015
Creator/Author
Sal Khan
Keyword
Cells

Visualising vectors in 2 dimensions

Visualising, adding and breaking down vectors in 2 dimensions.

Subject and Topic
Form 1
Physics
Force
Effects of forces
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2011
Creator/Author
Sal Khan
Keyword
Vectors
two dimensional motion

What is a force?

In this unit you will learn what a force is and find out about different types of forces. This will allow you to identify forces at work in your everyday life and understand the effects of forces.

Subject and Topic
Form 1
Physics
Force
Effects of forces
Resource Type
Studieboeken
Language
English
Publisher
Department of Higher Education
Publication Date
No date
Creator/Author
Linda Pretorius
Contributor
Michael Atkinson
Keyword
Force
External Force
Net Force