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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

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.
Onderwerp en thema
Form 1
Biology
Introduction to biology
Scientific processes in biology
Type bron
Simulatie
Taal
English
Uitgever
pHET Interactive Simulations
Publicatiedatum
2023
Schepper/Auteur
Diana López Tavares
Jonathan Olson
Trefwoord
Density
Mass
Volume
Archimedes' Principle

Evolution Clarification Swahili

Clarifying some points on evolution and intelligent design.

Onderwerp en thema
Form 1
Biology
Introduction to biology
Scientific processes in biology
Type bron
Video
Taal
English
Uitgever
KhanAcademyKiswahili
Publicatiedatum
2012
Schepper/Auteur
Khan Academy
Deelnemer
KhanAcademyKiswahili
Trefwoord
Evolution
Human Evolution

Forces and Motion: Basics

  • Identify when forces are balanced vs unbalanced.
  • Determine the sum of forces (net force) on an object with more than one force on it.
  • Predict the motion of an object with zero net force.
  • Predict the direction of motion given a combination of forces.
Onderwerp en thema
Form 2
Physics
Motion in a straight line
Distance and displacement
Type bron
Simulatie
Taal
English
Uitgever
pHET Interactive Simulations
Publicatiedatum
No date
Schepper/Auteur
Noah Podolefsky (Lead)
Trefwoord
Force
Motion
Friction
Speed

Human fertilisation and early development

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

Onderwerp en thema
Form 1
Biology
Introduction to biology
Scientific processes in biology
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2017
Schepper/Auteur
Sal Khan
Trefwoord
fertilisation

Impact velocity from given height

Determining how fast something will be traveling upon impact when it is released from a given height. 

Onderwerp en thema
Form 2
Physics
Motion in a straight line
Distance and displacement
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2011
Schepper/Auteur
Sal Khan
Trefwoord
Initial Velocity
One dimensional motion

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

Mitosis

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

Onderwerp en thema
Form 1
Biology
Introduction to biology
Scientific processes in biology
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2015
Schepper/Auteur
Sal Khan
Trefwoord
Mitosis
Cells

Motion in Two Dimensions

In this chapter, we’ll use vectors to expand our understanding of forces and motion into two dimensions. Most real-world physics problems (such as with the game of pool pictured here) are, after all, either two- or three-dimensional problems and physics is most useful when applied to real physical scenarios. We start by learning the practical skills of graphically adding and subtracting vectors (by using drawings) and analytically (with math). Once we’re able to work with two-dimensional vectors, we apply these skills to problems of projectile motion, inclined planes, and harmonic motion.

Onderwerp en thema
Form 2
Physics
Motion in a straight line
Distance and displacement
Type bron
Studieboeken
Taal
English
Uitgever
openstax
Publicatiedatum
2020
Schepper/Auteur
Openstax
Trefwoord
Resultant
Resultant vector
Tail
Graphical method