Overview of animal and plant cells
Description

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

Language
English
Resource Type
Publisher
Khan Academy
Publication Date
Creator/Author
Sal Khan
Cell theory
Description

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. 

Language
English
Resource Type
Publisher
Khan Academy
Publication Date
Creator/Author
Sal Khan
Scale of cells
Description

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.

Language
English
Resource Type
Publisher
Khan Academy
Publication Date
Creator/Author
Sal Khan
Forces
Subject and Topic
Description

By the end of this lesson you will be able to:

  1. Define and explain what a force is
  2. List and describe the main kinds of forces
  3. Explain the effects of a force
Language
English
Resource Type
Publication Date