Displaying 11 - 20 of 43 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

Chromosomal crossover in meiosis I

Meiosis is a process where germ cells divide to produce gametes, such as sperm and egg cells. In prophase I of meiosis, chromosomes condense and homologous recombination takes place, leading to genetic variation through chromosomal crossover. This forms a tetrad, which is made up of four chromatids (two sister chromatids per chromosome).

Subject and Topic
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2015
Creator/Author
Sal Khan
Keyword
Meiosis

Colour Vision

Outcomes:

  • Determine what color the person sees for various combinations of red, green, and blue light.
  • Describe the color of light that is able to pass through different colored filters.
Subject and Topic
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Resource Type
Simulatie
Language
English
Publisher
pHET Interactive Simulations
Publication Date
No date
Creator/Author
Bryce Gruneich (lead)
Kathy Perkins (lead)
Keyword
Photons
Monochromatic Light
White Light
Rainbows

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.

Subject and Topic
Form 1
Biology
Cell structure and organisation
Plant and animal cells
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2022
Creator/Author
Khan Academy
Keyword
Animal cell
Plant cell

Comparing mitosis and meiosis

Comparison of the processes of mitosis and meiosis. Mitosis produces two diploid (2n) somatic cells that are genetically identical to each other and the original parent cell, whereas meiosis produces four haploid (n) gametes that are genetically unique from each other and the original parent (germ) cell. Mitosis involves one cell division, whereas meiosis involves two cell divisions.

Subject and Topic
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2015
Creator/Author
Sal Khan
Keyword
Meiosis
Mitosis

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

DNA

Learn about DNA (deoxyribonucleic acid). Overview of DNA bases, complementary base pairing, and the structure of the double helix.

Subject and Topic
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2014
Creator/Author
Sal Khan
Keyword
DNA

Energy and fields

When two objects interacting through a field change relative position, the energy stored in the field is changed.

Subject and Topic
Form 1
Physics
Work, energy and power
Energy
Resource Type
Video
Language
English
Publisher
Khan Academy
Publication Date
2021
Creator/Author
Khan Academy
Keyword
Energy
Energy Field

Energy Skate Park: Basics

  • Explain the Conservation of Mechanical Energy concept using kinetic energy (KE) and gravitational potential energy (PE).
  • Describe how the Energy Bar and Pie Charts relate to position and speed.
  • Explain how changing the Skater Mass affects energy.
  • Explain how changing the Track Friction affects energy.
  • Predict position or estimate speed from Energy Bar and Pie Charts.
  • Calculate speed or height at one position from information about a different position.
  • Calculate KE and PE at one position from information about a different position.
  • Design a skate park using the concepts of mechanical energy and energy conservation.
Subject and Topic
Form 1
Physics
Work, energy and power
Energy
Resource Type
Simulatie
Language
English
Publisher
pHET Interactive Simulations
Publication Date
No date
Creator/Author
Noah Podolefsky (Lead)
Keyword
Law of conservation of energy
Kinetic Energy
Energy
Friction