In what case would a female have a sex linked trait?

a
if the mother has the trait and the father does not
b
if a mother is a carrier or has the trait and the father has the trait
c
if a mother does not have the trait and the father is a carrier
d
if the mother does not have the trait and is not a carrier but the father does

Which represents the cross between parent plants if one is heterozygous for yellow-colored pods and the other is homozygous for green-colored pods? yy  ´    ´    ´    ´  yy

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point

Suppose you are provided with an actively dividing culture of e. coli bacteria to which radioactive thymine has been added. what would happen if a cell replicates once in the presence of this radioactive base?