Igcse Model Questions Vol1 2024 Biology Question 10

Practice essay / theory question 10 from the 2024 Igcse Model Questions Vol1 Biology examination. This question covers Genetic Inheritance, Mendelian Genetics, Molecular Basis of Disease, Genetic Counseling .

Igcse Model Questions Vol1 2024 Biology Essay / Theory
Topics: Genetic Inheritance Mendelian Genetics Molecular Basis of Disease Genetic Counseling
Question 10 IGCSE_MODEL_QUESTIONS_VOL1 • 2024 • BIOLOGY • essay

In a small community, a rare autosomal recessive disorder called X‑linked‑like Cystic Fibrosis (CF) has been reported. The disorder is characterised by thick mucus production, recurrent lung infections and pancreatic insufficiency. The pedigree below shows three generations of a family in which the disorder is present. The proband (individual III‑2) is affected. The parents of the proband are both clinically healthy. [The pedigree is described in the stem; no visual is required for the question.]

Question Parts

( a )
Using the information given, determine the most likely mode of inheritance of the disorder and justify your answer with reference to the pedigree pattern.
( b )
If both parents of the proband are heterozygous carriers, calculate the probability that a future child of theirs will be affected, will be a carrier, and will be completely unaffected.
( c )
Explain the molecular basis of cystic fibrosis, specifying the type of mutation most commonly involved and how this mutation affects the CFTR protein function.

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About This Question

This is Igcse Model Questions Vol1 2024 Biology Question 10. It is one of the essay questions from the 2024 Igcse Model Questions Vol1 Biology examination.

The question covers Genetic Inheritance, Mendelian Genetics, Molecular Basis of Disease, Genetic Counseling .

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