Explain why color-blindness is much more common in males than in females. What will be an ideal response?
ANSWER: Color blindness is an X-linked recessive trait. Because males are hemizygous for all genes on
the X chromosome, they express all recessive allele phenotypes for genes on this
chromosome. Therefore, hemizygous males are affected, but only homozygous females are
affected. Stated another way, affected males who receive the mutant allele from their mothers
transmit it to all their daughters but not to any of their sons. However, daughters of affected
males are typically heterozygous and therefore unaffected, but sons of heterozygous females
each have a 50% chance of receiving the recessive gene and being affected. In order for
females to be affected, they must inherit the recessive allele from both parents, while males
only need to inherit the allele from their mother.
You might also like to view...
The order of mammals to which humans belong is the ________
Fill in the blank(s) with correct word
Humans are the only surviving member of this genus, although other members of this genus existed in the past.
A. mammalia B. Homo C. sapiens D. primates
Phytoremediation is the use of a plant's ability to uptake minerals in order to remove pollutants from the environment.
Answer the following statement true (T) or false (F)
One of Jake and Lucy's kittens mates with another cat that has 18 total toes. What is the probability that one of their offspring would have 18 total toes?
A) 100% B) 75% C) 50% D) 0%