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Use the following information to answer Questions 5–7 - VCE - SSCE Biology - Question 5 - 2003 - Paper 1
Question 5
Use the following information to answer Questions 5–7. The pedigree in Figure 2 shows the inheritance of Tay Sachs disease, a progressive neurological defect in hum... show full transcript
Worked Solution & Example Answer:Use the following information to answer Questions 5–7 - VCE - SSCE Biology - Question 5 - 2003 - Paper 1
Step 1
It is reasonable to conclude from the pedigree that the trait shown is
Answer
To determine the mode of inheritance for Tay Sachs disease as presented in the pedigree:
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Observe the pattern of affected individuals: In the pedigree, the disease appears to manifest in both males and females across multiple generations. This suggests that the trait is likely not X-linked since X-linked traits often exhibit a pattern where males are more frequently affected than females.
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Analyze the inheritance pattern: Notably, in the pedigree, affected individuals (shown by filled symbols) have at least one affected parent, supporting an autosomal pattern of inheritance. In autosomal recessive conditions, the trait can skip generations, which appears to be consistent in this case.
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Conclude the mode of inheritance: Given the observed data from the pedigree, it is reasonable to deduce that Tay Sachs disease is inherited in an autosomal recessive manner. Therefore, the correct answer is C.