Meiosis 10.1 HL

This topic is all about the higher level details of meiosis. That includes the formation of a chiasmata in crossing over and the movement of chromosomes during the two division of meiosis. Remember some of the details of meiosis have also been covered in the standard level topic Meiosis 3.3.


Key words

Learn and test your biological vocabulary using these 10.1 Meiosis flashards

Clean sweep - quick revision through the whole topic

These slides summarise the essential understanding and skills in this topic. 
They contain short explanations in text and images - great revision.

Read the slides and look up any words or details you find difficult to understand.

Structured question about meiosis

Explaining the movement of chromosomes is an important skill from this topic.

Answer the question below, on a piece of paper, then check your answer against the model answer below.

Describe crossing over and the formation of a chiasma. Credit will be given to labelled diagrams. [4]

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Revision summary list for 10.1 Meiosis

Crossing over

  • DNA replication makes a second chromatid in each chromosome in interphase before meiosis.
  • Crossing over exchanges pieces of DNA between non-sister homologous chromatids and forms new combinations of alleles on the chromosomes formed in meiosis.
  • Chiasmata are the crossing over points

Chromosomes movements

  • Details of chromosome movements in meiosis. ie:
    • Homologous chromosomes separate in meiosis I.
    • Sister chromatids separate in meiosis II.
  • Random orientation of homologous chromosomes in meiosis I leads to independent assortment of alleles.

Student skills and applications

  • Drawing diagrams to show chiasmata formed by crossing over.
  • show sister chromatids still closely aligned, except at the point where crossing over occurred and a chiasma was formed.

Revision mind map

This diagram summaries the main sections of topic 10.1
Test if you can draw something like these concept maps from memory.

Review questions

This is a self marking quiz containing questions covering the topic outlined above.
Try the questions to check your understanding.


START QUIZ!

Revision fun activity

Everyone needs a bit of fun while they revise. Try this meiosis card matching game.
Can you reach the leader board?