6 (a) A karyogram is a picture of the chromosomes found in the nucleus of a single cell - Edexcel - GCSE Biology - Question 6 - 2019 - Paper 1
Question 6
6 (a) A karyogram is a picture of the chromosomes found in the nucleus of a single cell.
Figure 8 shows a human karyogram.
(i) State two reasons why this karyogram ... show full transcript
Worked Solution & Example Answer:6 (a) A karyogram is a picture of the chromosomes found in the nucleus of a single cell - Edexcel - GCSE Biology - Question 6 - 2019 - Paper 1
Step 1
State two reasons why this karyogram cannot be from a gamete (sex cell).
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Answer
A karyogram of a gamete contains 23 chromosomes, while this one has 46.
The karyogram shows homologous pairs of chromosomes which are not found in gametes.
Step 2
State the gender shown by this karyogram.
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Answer
The karyogram shows a male as indicated by the presence of one X and one Y chromosome.
Step 3
Complete the Punnett square to show how gender is inherited.
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Answer
Y
Y
X
XY
XY
X
XY
XY
Step 4
State the probability that a child will be male.
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Answer
The probability that a child will be male is 50%.
Step 5
Name structure Z.
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Answer
Structure Z is the acrosome.
Step 6
Explain why sperm B will be more likely to fertilise an egg than sperm A if they were both released at the same time.
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Answer
Sperm B has a larger middle section which contains more mitochondria, providing it with more energy to swim towards the egg. This increased energy reserve allows sperm B to swim faster and more effectively, increasing its chances of fertilising the egg.
