Figure 1 shows a cell from an onion root tip - Edexcel - GCSE Biology Combined Science - Question 1 - 2021 - Paper 1
Question 1
Figure 1 shows a cell from an onion root tip. This cell is dividing by mitosis.
(a) (i) Which structure is labelled Z?
A allele
B chromosome
C spindle
D nuclear... show full transcript
Worked Solution & Example Answer:Figure 1 shows a cell from an onion root tip - Edexcel - GCSE Biology Combined Science - Question 1 - 2021 - Paper 1
Step 1
Which structure is labelled Z?
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Answer
The structure labelled Z is a chromosome (B). This can be identified as it is a visible structure during the cell division process of mitosis.
Step 2
Mitosis produces new cells. Give two reasons why mitosis is important in living things.
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Answer
Mitosis is crucial for growth as it allows multicellular organisms to increase in size by producing more cells.
It is also essential for repair and regeneration of tissues, ensuring that damaged cells are replaced to maintain healthy functioning.
Step 3
Draw one straight line from each stage of the cell cycle to its description.
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Answer
Interphase - DNA is copied
Prophase - a spindle is formed
Telophase - the nuclear membrane breaks down
Cytokinesis - the cell divides in two
Step 4
State what can be added to the slide to make the plant cells more visible.
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A stain or dye can be added to the slide to enhance visibility of the plant cells.
Step 5
Which is the total magnification of this microscope?
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The total magnification is D x400, calculated by multiplying the magnification of the eyepiece (x10) and the objective lens (x40).
Step 6
Name one part of a light microscope that can be moved to obtain a clear image of plant cells.
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The focus knob is a part of a light microscope that can be moved to achieve a clear image of the plant cells.
