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Figure 7 shows cells from an onion root tip as seen using a light microscope - Edexcel - GCSE Biology - Question 5 - 2021 - Paper 1
Question 5
Figure 7 shows cells from an onion root tip as seen using a light microscope. cell Q cell R Identify the stages of mitosis shown in cell Q and cell R. cell Q | ... show full transcript
Worked Solution & Example Answer:Figure 7 shows cells from an onion root tip as seen using a light microscope - Edexcel - GCSE Biology - Question 5 - 2021 - Paper 1
Step 1
Identify the stages of mitosis shown in cell Q and cell R.
Answer
The correct answer is:
- Cell Q: B (telophase)
- Cell R: A (anaphase)
This means that in cell Q, the cell is in the telophase stage, characterized by the separation of the chromosomes and the formation of two nuclei. In cell R, the cell is in the anaphase stage, where the sister chromatids are being pulled apart toward opposite poles of the cell.
Step 2
Describe two processes that occur in cells during prophase.
Answer
During prophase, the following two processes occur:
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Chromatin Condensation: The chromatin fibers condense into visible chromosomes, each consisting of two sister chromatids joined at the centromere. This makes the chromosomes easier to manipulate as the cell prepares for division.
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Nuclear Envelope Breakdown: The nuclear envelope, which encloses the nucleus, begins to disintegrate. This allows the spindle fibers to access the chromosomes, facilitating their movement during later stages of mitosis.