20.3 Dihybrid inheritance Flashcards
1
Q
what is dihybrid inheritance?
A
when two genes are inherited
so two different characteristics
2
Q
what is the expected phenotypic ratio in heterozygous dihybrid cross?
A
9:3:3:1
3
Q
why can the actual ratio of offspring produced differ from the expected?
A
- due to the random nature of fertilisation of gametes
- when crossing over does not occur
4
Q
when may crossing over not occur?
A
if the location of the genes on the chromosome are too close together
means that both characteristics are inherited together
