Question

This pedigree chart tracks the inheritance of a recessive trait that is not sex-linked. Based on the information in the chart, which of the following statements is true about individuals 3 and 4?

A. At least one is heterozygous for the trait.
B. They are both homozygous dominant for the trait. C. They are both heterozygous for the trait.
D. At least one is homozygous for the trait.

Can you explain this to me? @Abhisar

Answer 1

@alphadxg @Abhisar

Answer 2

what do u think should be the correct option ?

Answer 3

A

Answer 4

@Abhisar is that correct?

Answer 5

ohkay let's see

Answer 6

as u said, let us suppose one is heterozygous and other is homozygous dominant

Answer 7

let us represent the recessive allele by r and dominant allele by R

Answer 8

u understand upto this ?

Answer 9

yep

Answer 10

So clearly thats the wrong answer -- cause all are dominant

Answer 11

would it be D then

Answer 12

yes, that's wrong because all are having dominant phenotype

Answer 13

D can not pe possible since neither 3 nor 4 express the trait. u getting this ?

Answer 14

*be

Answer 15

oh right!!

Answer 16

They are carriers !

Answer 17

its B then

Answer 18

correct?

Answer 19

If they were both homozygous for the trait, then there progeny would never had a recessive phenotype !

Answer 20

i meant C sorry :S