Cell division 1.6

The control of cell division is just as essential for the survival of multicellular organisms as it is for the reproduction of single celled organisms.  This topic covers the movement of chromosomes in the division of eukaryotic cells by mitosis. There is a section about the control of the cell cycle and how some cells can begin dividing out of control and cause cancer. The differences between primary and secondary tumours are also included.

Key concepts

Learn and test your biological vocabulary for 1.6 Cell division using these flashcards.


Essentials

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

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

Summary

Summary list for 1.6 Cell division

  • Mitosis is division of the nucleus into two genetically identical daughter nuclei.
  • Chromosomes condense by supercoiling during mitosis.
  • Cytokinesis occurs after mitosis and is different in plant and animal cells.
  • Interphase is a very active phase of the cell cycle with many processes occurring in the nucleus and cytoplasm.(including G1, S, G2).
  • Cyclins are involved in the control of the cell cycle.
  • Mutagens, oncogenes and metastasis are involved in the development of primary and secondary tumours.

Skills

  • Skill: Identification of phases of mitosis in cells viewed with a microscope or in a micrograph.(prophase, metaphase, anaphase and telophase).
  • Skill: Determination of a mitotic index from a micrograph.
  • Application: The correlation between smoking and cases of cancer.

Mindmaps

These diagram summaries cover the main sections of topic 1.6 Cell division.
Study them and draw your own list or concept map from memory.

Exam style questions

Exam style question about gene mutations and cancer

Answer the question below, which addresses one application of DNA replication.
(Thanks to Catarina Gouveia and her students for the question and markscheme)

Outline how the exposure to ionising radiation, such as UV, can increase the risk of developing cancer. [5]

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Click the + icon to see a model answer.

Extra exam question on mitosis stages and mitotic index  - - -  click the + symbol to open it -- >

Exam style question about mitotic index

Answer the question below, which addresses the skill of calculating the mitotic index.

The image below shows twenty six cells from tissue in a plant root.

Identify the stage of mitosis in the cells A,B,C. [3]

A ..................................................

B ..................................................

C ..................................................

If these three cells are the only ones undergoing mitosis calculate the mitotic index of this tissue.

Give the mitotic index as a percentage.   Show your working.    [3]

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Click the + icon to see a model answer.

Extra exam question on the process of mitosis

Exam style question about the process of mitosis

This question requires knowledge of the process of mitosis.

Explain how the process of mitosis produces identical daughter cells. (5 marks).

 

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Explain means give the reasons, not just a description.
This question is not about the stages of mitosis but how the process produces identical cells.

Click the + icon to see a model answer.

 

Test yourself

Multiple choice questions

This self-marking quiz contains questions covering the understandings for this topic.


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Drag and drop activities

Test your ability to construct biological explanations using the drag and drop questions below.

Test your construction of biological explanations using the drag and drop questions below.

Cytokinesis in plant and animal cells.

Drag and drop the correct term into the gap to describe cytokinesis.

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cellulose fuse equator cell walls membrane exocytosis centre merged contractile nuclear rigid cell

Cytokinesis ( division) begins towards the end of mitosis ( division).

In animal cells, proteins pull the opposite sides of the membrane towards the of the cell. The membranes and two cells are formed.

Plant celIs have and are in structure so each cell forms a plasma membrane and then deposits a middle lamella and cell wall outside the membrane. To form the , vesicles are at the of the cell, the contents of the vesicle forming a plasma membrane between the two nuclei. Two new cell walls are then formed on the membrane by and assembly of and pectins.

In the plant cell, the membrane and wall have to be formed between the two cells using vesicles which move to the equator of the cell. In an animal cell, the opposite sides of the plasma membranes are pulled towards the centre and fuse.


Just for fun

If you want to review key terminology and have some fun with your revision try this word shoot game Cell Division arcades game