A student observes a series of cells undergoing mitosis. The student notices that in some cells the chromatids are being pulled to opposite poles of the cell, whilst in other cells the chromosomes are lined up at the cell equator. Explain the stages of mitosis that the student is observing, and describe what happens after mitosis is complete to produce two new daughter cells.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Mitosis is a form of cell division that produces two genetically identical daughter cells from one parent cell. It occurs in a series of distinct stages.
Model answer (5 marks)
Metaphase – the chromosomes line up at the cell equator.
Anaphase – the sister chromatids are pulled apart to opposite poles by spindle fibres.
After mitosis, cytokinesis divides the cytoplasm, producing two new daughter cells.
The daughter cells are genetically identical to each other and to the parent cell, and each is diploid with a full set of chromosomes.
Anaphase – the sister chromatids are pulled apart to opposite poles by spindle fibres.
After mitosis, cytokinesis divides the cytoplasm, producing two new daughter cells.
The daughter cells are genetically identical to each other and to the parent cell, and each is diploid with a full set of chromosomes.
Examiner tips
- Use the exact terms metaphase, anaphase, cytokinesis; mention spindle fibres in anaphase; state that daughter cells are identical and diploid
Common mistakes
- Confusing metaphase with anaphase; omitting spindle fibres; forgetting to mention cytokinesis; not stating that daughter cells are genetically identical and diploid
Mark scheme (5 marks)
- The stage where chromosomes align at the cell equator is metaphase
- The stage where chromatids are pulled to opposite poles is anaphase
- Spindle fibres pull the chromatids to opposite poles during anaphase
- After mitosis, cytokinesis occurs — the cytoplasm divides to produce two new daughter cells
- The two daughter cells produced are genetically identical to each other and to the parent cell / each daughter cell is a diploid cell containing a full set of chromosomes
Key terms in this question
mitosis · chromatid · daughter cells
Related
- All Pearson Edexcel A-Level Biology A (9BI0) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
More Cell cycle and mitosis questions
- During the cell cycle, a cell undergoes interphase before mitosis begins. Explai…
- A tumour is a mass of cells that forms when the cell cycle is no longer controll…
- A cell in the root tip of a pea plant completes the cell cycle and produces two …
- Explain how a diploid skin cell produces two genetically identical daughter cell…