OBJECTIVE LIFE SCIENCE
GENETICS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
The parents may both have recessive genes for blue eyes.
|
|
|
The child was born at sea on a cruise ship
|
|
|
Eye color in humans is not an inherited trait
|
|
|
The child was deprived of oxygen during its birth
|
Detailed explanation-1: -Brown eye colour is dominant over blue eye colour. Therefore, for the brown-eyed parents having blue-eyed child, the possibility is that both have heterozygous genotype i.e. Bb. Therefore, from the square below, it is clear that there is a 25% possibility of blue-eyed (bb) child.
Detailed explanation-2: -If both the parents have brown eyes, then there is generally a 25% chance for their child to have blue eyes. Because both the brown-eyed parents have a recessive blue-eye gene and can pass it to the next generation. However, since eye color is polygenic, several other genes exert their effects as well.
Detailed explanation-3: -Since blue is recessive to brown, Bb people have brown eyes. But they can pass a “b” down to their kids, who might end up with blue eyes.