31 - 40 van 239 bronnen weergeven

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

Charges and Fields

  • Determine the variables that affect the strength and direction of the electric field for a static arrangement of charges.
  • Investigate the variables that affect the strength of the electrostatic potential (voltage).
  • Explain equipotential lines and compare them to the electric field lines.
  • For an arrangement of static charges, predict the electric field lines. Verify the prediction using vector addition.
Onderwerp en thema
Form 1
Physics
Force
Types of forces
Type bron
Simulatie
Taal
English
Uitgever
pHET Interactive Simulations
Publicatiedatum
No date
Schepper/Auteur
Amy Rouinfar (lead designer - HTML5)
Trefwoord
Electric Field
Voltage
Electrostatics

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).

Onderwerp en thema
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2015
Schepper/Auteur
Sal Khan
Trefwoord
Meiosis

Circle Terminology

There are some key words that you need to know for circles: radius, circumference, diameter, sector, segment, tangent, chord and arc. In this video you will discover what they all mean.

Onderwerp en thema
Form 1
Mathematics
Geometry
Circles
Type bron
Video
Taal
English
Uitgever
FuseSchool Global Education
Publicatiedatum
2017
Schepper/Auteur
FuseSchool Global Education
Trefwoord
Circles

Circles

This video discusses the topic of circles.

Onderwerp en thema
Form 1
Mathematics
Geometry
Circles
Type bron
Video
Taal
English
Uitgever
TicTac Learn
Publicatiedatum
2020
Schepper/Auteur
TicTac Learn
Trefwoord
Circles

Closure Property of Whole Numbers: 3 Videos

Part 1: Closure property of whole numbers with specific reference to adding, subtracting, multiplying and dividing whole numbers
Part 2: Examples of closure property of whole numbers
Part 3: Common mistakes and misconceptions

Onderwerp en thema
Form 1
Mathematics
Numbers I
Natural and whole numbers
Type bron
Video
Taal
English
Uitgever
TicTac Learn
Publicatiedatum
2020
Schepper/Auteur
TicTac Learn
Trefwoord
Whole numbers
Closure property of whole numbers

Links

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.
Onderwerp en thema
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Type bron
Simulatie
Taal
English
Uitgever
pHET Interactive Simulations
Publicatiedatum
No date
Schepper/Auteur
Bryce Gruneich (lead)
Kathy Perkins (lead)
Trefwoord
Photons
Monochromatic Light
White Light
Rainbows

Commutative Property of Whole Numbers: 3 Videos

Part 1: Commutative property of whole numbers under addition, subtraction, multiplication and division 
Part 2: Examples of commutative property of whole numbers under addition and multiplication
Part 3: Common mistakes and misconceptions

Onderwerp en thema
Form 1
Mathematics
Numbers I
Natural and whole numbers
Type bron
Video
Taal
English
Uitgever
TicTac Learn
Publicatiedatum
2020
Schepper/Auteur
TicTac Learn
Trefwoord
Whole numbers
Commutative property of whole numbers

Links

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.

Onderwerp en thema
Form 1
Biology
Cell structure and organisation
Plant and animal cells
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2022
Schepper/Auteur
Khan Academy
Trefwoord
Animal cell
Plant cell