Question

Due to nondisjunction of chromosomes during spermatogenesis, sperms carry both sex chromosomes (22A + XY) and some sperms do not carry any sex chromosome (22A + O). If these sperms fertilise normal eggs (22A + X), what types of genetic disorders appear among the offsprings?
A) Turner's syndrome and Klinefelter's syndrome
B) Down's syndrome and Klinefelter's syndrome
C) Down's syndrome and Turner's syndrome
D)Down's syndrome and cri du-chat syndrome

Answer 1

Hint:Nondisjunction of chromosome is Failure of paired chromosomes to separate (to disjoin) during cell division, so that both chromosomes move to one daughter cell and none move to the other daughter cell.

Complete answer:
Disorders of chromosome number incorporate the duplication or loss of whole chromosomes, just as changes in the quantity of complete arrangements of chromosomes. They are brought about by nondisjunction, which happens when sets of homologous chromosomes or sister chromatids neglect to isolate during meiosis. Nondisjunction can happen during either meiosis I or II, with various outcomes . In the event that homologous chromosomes neglect to isolate during meiosis I, the outcome is two gametes that do not have that chromosome and two gametes with two duplicates of the chromosome. In the event that sister chromatids neglect to isolate during meiosis II, the outcome is one gamete that does not have that chromosome, two ordinary gametes with one duplicate of the chromosome, and one gamete with two duplicates of the chromosome.

So, the correct answer is option A.

Note:Turner disorder (TS), otherwise called 45,X or 45,X0, is a condition wherein a female is mostly or totally missing a X chromosome. Turner disorder is because of a chromosomal anomaly wherein all or part of one of the X chromosomes is absent or adjusted. While the vast majority have 46 chromosomes, individuals with TS generally have 45. Klinefelter disorder (KS) otherwise called 47, XXY or XXY, is the arrangement of side effects that result from at least two X chromosomes in males.