1 - 7 van 7 bronnen weergeven

Biodiversity and natural selection

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

Onderwerp en thema
Form 2
Biology
Balance of nature
The natural environment
Type bron
Video
Taal
English
Uitgever
California Academy of Sciences
Publicatiedatum
2014
Schepper/Auteur
California Academy of Sciences
Trefwoord
Biodiversity
Natural selection

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

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

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.

Onderwerp en thema
Form 2
Physics
Newton's law of motion
2nd law of motion
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2016
Schepper/Auteur
David SantoPietro
Trefwoord
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.

Onderwerp en thema
Form 2
Physics
Newton's law of motion
2nd law of motion
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2012
Schepper/Auteur
Sal Khan
Trefwoord
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.

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