Displaying 1 - 10 of 11 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

Density

Outcomes:

  • Describe how the concept of density relates to an object's mass and volume.
  • Explain how objects of similar mass can have differing volume, and how objects of similar volume can have differing mass.
  • Explain why changing an object's mass or volume does not affect its density (ie, understand density as an intensive property).
  • Measure the volume of an object by observing the amount of fluid it displaces.
  • Identify an unknown material by calculating its density and comparing to a table of known densities.
Subject and Topic
Form 1
Biology
Introduction to biology
Scientific processes in biology
Resource Type
Simulatie
Language
English
Publisher
pHET Interactive Simulations
Publication Date
2023
Creator/Author
Diana López Tavares
Jonathan Olson
Keyword
Density
Mass
Volume
Archimedes' Principle

Evolution Clarification Swahili

Clarifying some points on evolution and intelligent design.

Subject and Topic
Form 1
Biology
Introduction to biology
Scientific processes in biology
Resource Type
Video
Language
English
Publisher
KhanAcademyKiswahili
Publication Date
2012
Creator/Author
Khan Academy
Contributor
KhanAcademyKiswahili
Keyword
Evolution
Human Evolution

Human fertilisation and early development

Overview of fertilisation and early human development. From conception leading to a zygote to blastocyst, embryo and fetus.

Subject and Topic
Form 1
Biology
Introduction to biology
Scientific processes in biology
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2017
Creator/Author
Sal Khan
Keyword
fertilisation

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

Mitosis

Mitosis is how cells divide! Learn what happens in all the phases of mitosis: prophase, metaphase, anaphase, and telophase.

Subject and Topic
Form 1
Biology
Introduction to biology
Scientific processes in biology
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2015
Creator/Author
Sal Khan
Keyword
Mitosis
Cells

More on Newton's second law

An elaboration on how to use Newton's second law when dealing with multiple forces, forces in two dimensions, and diagonal forces.

Subject and Topic
Form 2
Physics
Newton's law of motion
2nd law of motion
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2016
Creator/Author
David SantoPietro
Keyword
Second Law of Motion
Motion
Newton

Newton's second law of motion

Newton's second law of motion is F = ma, or force is equal to mass times acceleration. Learn how to use the formula to calculate acceleration.

Subject and Topic
Form 2
Physics
Newton's law of motion
2nd law of motion
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2012
Creator/Author
Sal Khan
Keyword
Laws of motion
Second Law of Motion
Newton

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