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Phases of meiosis I

How homologous chromosomes separate into two sets. Prophase I, metaphase I, anaphase I, and telophase I.

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

Phases of meiosis II

Meiosis is a process that creates sex cells (gametes) with half the number of chromosomes of the parent cell. Meiosis has two stages: meiosis I and meiosis II. In meiosis I, homologous chromosomes pair up and exchange genetic material (crossing over). In meiosis II, sister chromatids separate, creating four haploid cells.

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

Resistance in an electric circuit

Electrical devices convert the electrical energy carried by the charges into other types of energy such as heat, sound, and motion. Components in the appliance resist the flow of charge and are referred to as resistors. In this unit1 you will understand what resistance is, the factors that affect the resistance and the relationship between resistance and current.

Onderwerp en thema
Form 2
Physics
Current electricity
Concept of current electricity
Type bron
Werkbladen en klassikale activiteiten
Taal
English
Uitgever
Department of Higher Education
Publicatiedatum
No date
Schepper/Auteur
Leigh Kleynhans
Deelnemer
Michael Atkinson
Trefwoord
Electric current
Resistance
Ohm's Law

Safety with electricity

Most of us use electricity every day in many different ways so it is important that we understand the dangers, or hazards, associated with electricity and we know how to use it safely.

Onderwerp en thema
Form 2
Physics
Current electricity
Concept of current electricity
Type bron
Studieboeken
Taal
English
Uitgever
Department of Higher Education
Publicatiedatum
No date
Schepper/Auteur
Leigh Kleynhans
Deelnemer
Michael Atkinson
Trefwoord
Voltage
Electric current
Ohm's Law

pH Scale

Outcomes:

  • Determine if a liquid is acidic, basic, or neutral
  • Place acids or bases in relative order
  • Describe on a molecular scale, with illustrations, how the water equilibrium varies with pH
  • Determine concentration of hydroxide, hydronium and water at a given pH
  • Relate liquid color to pH
  • Predict (qualitatively and quantitatively) how dilution and volume will affect the pH and concentration of hydroxide, hydronium and water
Onderwerp en thema
Form 1
Biology
Introduction to biology
The biology laboratory
Type bron
Simulatie
Taal
English
Uitgever
pHET Interactive Simulations
Publicatiedatum
No date
Schepper/Auteur
Yuen-ying Carpenter (lead)
Trefwoord
pH
Dilution
Concentration
Acids
Bases

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

Skeletal structure and function

Skeletons support and protect our bodies. Bugs have exoskeletons outside their bodies, while humans have endoskeletons inside. Our bones are in axial (skull, ribcage, spine) and appendicular (arms, legs) groups. Bone marrow makes blood cells; more specifically, red marrow makes blood and yellow marrow stores fat. 

Onderwerp en thema
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2014
Schepper/Auteur
Tracy Kim Kovach
Trefwoord
Skeletal structure

Sura za Meiosisi - Phases of Meiosis

The phases of Meiosis.

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

Urination

Micturition (peeing) starts with urine flowing from the kidneys to the bladder via ureters. The bladder expands using transitional epithelium. Urine exits through the urethra, controlled by internal and external urethral sphincters. Ureters prevent backflow, thereby reducing infection risk

Onderwerp en thema
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2014
Schepper/Auteur
Raja Narayan
Trefwoord
Urination

Voltage in an electric circuit

When a circuit is connected and complete, charge can move through the circuit. Charge will not move unless there is a reason, a force to drive it around the circuit. Think of it as though charge is at rest and some- thing has to push it along. This means that work needs to be done to make charge move. A force acts on the charges, doing work, to make them move. The force is provided by the battery in the circuit.

Onderwerp en thema
Form 2
Physics
Current electricity
Concept of current electricity
Type bron
Studieboeken
Taal
English
Uitgever
Department of Higher Education
Publicatiedatum
No date
Schepper/Auteur
Leigh Kleynhans
Deelnemer
Michael Atkinson
Trefwoord
Resistance
Voltage
Series Circuit
Emf