Question

In a suburb of London (England) called Lower-East Hempstead, an allele at a unique locus on the Y chromosome of the men in this community gives rise to a phenomenon called “blood-shot eye”, which makes them look like they have a permanent hangover. Assuming that this is a closed community, which one of the following answers would best describe the F1 generational offspring of a blood-shot eyed male and a phenotypically normal eyecoloured female. A All offspring will have blood-shot eye B Half the offspring will have blood-shot eye C All the male offspring would die D Only half the female offspring would have blood-shot eye E All offspring will have normally coloured eyes F Half the men in Lower-East Hempstead have become teetotal

Answer 1

B)Half the offspring will have blood-shot eye.

Explaination:

As red blood eye character is linked to Y gene so it is a type of y linked inheritance.

Parents X Y^R x XX

Gametes X, Y^R X

F1:

XX( normal eyed female)

XYR(red blood shot eyed male)

Percentage of F1 offspring with blood red eye is 50%

When red eyed male crosses with normal female then all male offspring are blood shot red eyed while all female child are normal because Y gene is present only in male not in female. So this means all male child which constitute half of F1 progeny have blood shot red eye trait while all female child which constitute other half part of F1 are normal eyed.