What Explanation is Generally Given for Lethality of Monosomic Individuals

Question

What explanation is generally given for lethality of monosomic individuals?
A)The loss of a single chromosome is not generally lethal,unless the individual is inbred.
B)Cells count the number of chromosomes they have and will undergo apoptosis when the chromosome number is incorrect.
C)Monosomic chromosomes cannot undergo mitosis correctly.
D)The gametes of monosomic individuals cannot undergo meiosis,and this is lethal.
E)Monosomy may unmask recessive lethals that are tolerated in heterozygotes carrying the wild- type allele.

Accepted Answer

Monosomy may unmask recessive lethals that are tolerated in heterozygotes carrying the wild- type allele. This means that when an individual is missing a chromosome, any recessive harmful mutations on that chromosome will be expressed in the phenotype because there is no corresponding wild-type allele to mask them. This can lead to lethality.