Sickle cell anaemia differs from haemophilia in that its gene is carried on:
Athe X chromosome, so it is sex-linked
Bthe Y chromosome, so only males inherit it
Ca plasmid, so it is inherited maternally
Dan autosome, so it is not sex-linked
Answer & Solution
Correct answer: D. an autosome, so it is not sex-linked
1. Sickle cell anaemia is controlled by a recessive gene like haemophilia.
2. But that gene sits on an autosome, one of the chromosomes that is not a sex chromosome.
3. So the condition appears with equal frequency in males and females.
4. A genetic cross for it uses ordinary allele letters, with no X or Y attached.
5. Using X and Y chromosomes to represent the sickle cell alleles was the single most common recorded error on this question.
_Source: NECTA ACSEE 2023 Biology 133/2, Question 4: Genetics_
Related questions
Plants used in Mendel's first-generation crosses were labelled the generation called:The probability of an event found by dividing occurrences by opportunities is described asA recessive disorder preventing proper metabolism of phenylalanine and tyrosine is:Ignoring seed colour, the share of a dihybrid F2 generation with round seeds is:In pea plants round seed shape is dominant over shape that is:The F2 phenotypic ratio from a standard dihybrid cross is:A cross between true-breeding parents differing in two characteristics is a:The rule that genes do not influence each other's sorting into gametes is the law of indep