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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. 

Onderwerp en thema
Form 1
Biology
Cell structure and organisation
Concept of cells
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2015
Schepper/Auteur
Sal Khan
Trefwoord
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).

Onderwerp en thema
Form 1
Biology
Cell structure and organisation
Concept of cells
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2022
Schepper/Auteur
Khan Academy
Trefwoord
Cells

Comparing animal and plant cells

Plant cells have a cell wall in addition to a cell membrane, whereas animal cells have only a cell membrane. Plants use cell walls to provide structure to the plant. Plant cells contain organelles called chloroplasts, while animal cells do not. Chloroplasts allow plants to make the food they need to live using photosynthesis.

Onderwerp en thema
Form 1
Biology
Cell structure and organisation
Plant and animal cells
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2022
Schepper/Auteur
Khan Academy
Trefwoord
Animal cell
Plant cell

Introduction to the cell

Introduction to the cell.

Onderwerp en thema
Form 1
Biology
Cell structure and organisation
Concept of cells
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2017
Schepper/Auteur
Sal Khan
Trefwoord
Cells

Overview of animal and plant cells

Overview of animal and plant cells. Topics include cell walls, vacuoles, chloroplasts, peroxisomes, lysosomes, mitochondria, etc.

Onderwerp en thema
Form 1
Biology
Cell structure and organisation
Plant and animal cells
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2015
Schepper/Auteur
Sal Khan
Trefwoord
Animal cell
Plant cell

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
Onderwerp en thema
Form 1
Biology
Introduction to biology
The biology laboratory
Type bron
Simulatie
Taal
English
Uitgever
pHET Interactive Simulations
Publicatiedatum
No date
Schepper/Auteur
Yuen-ying Carpenter (lead)
Trefwoord
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.

Onderwerp en thema
Form 1
Biology
Cell structure and organisation
Concept of cells
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2015
Schepper/Auteur
Sal Khan
Trefwoord
Cells

Visualising vectors in 2 dimensions

Visualising, adding and breaking down vectors in 2 dimensions.

Onderwerp en thema
Form 1
Physics
Force
Effects of forces
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2011
Schepper/Auteur
Sal Khan
Trefwoord
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.

Onderwerp en thema
Form 1
Physics
Force
Effects of forces
Type bron
Studieboeken
Taal
English
Uitgever
Department of Higher Education
Publicatiedatum
No date
Schepper/Auteur
Linda Pretorius
Deelnemer
Michael Atkinson
Trefwoord
Force
External Force
Net Force