Question

Inheritance patterns cannot always be explained by Mendels models of inheritance. If a pair of homologous chromosomes fails to separate during meiosis I, select the choice that shows the chromosome number of the four resulting gametes with respect to the normal haploid number (n)?

Answer 1

Answer:

n+1; n+1; n-1; n-1

Explanation:

Separation of homologous chromosomes during anaphase I result in a reduction of the chromosome number to half in the daughter cells of meiosis. If two homologous chromosomes of a pair fail to separate from each other, they both will move to the same pole. In this case, one daughter cell of meiosis I will have both the homologous chromosomes of a pair (n+1) while the other one will lack it (n-1). Meiosis II in these two daughter cells will form a total of four cells. Two of the daughter cells will have one extra chromosome (n+1) while the rest two will lack one chromosome from the haploid set (n-1).