More than One Gene More than One Character Flashcards
1
Q
What is a dihybrid cross?
A
- Cross two pure breeding lines
- Cross F1 to make F2
2
Q
What is a backcross?
A
F1 is mated to recessive parent
3
Q
What is a testcross?
A
Unknown is mated to unknown parent
4
Q
What is the law of independent assortment?
A
Chromosomes are far enough apart that they are unlinked
5
Q
What is complete dominance?
A
One trait is completely dominant over the other
6
Q
What is epistasis?
A
Genes interact to produce different phenotypes
7
Q
What is X chromosome inactivation?
A
- In each female gamete one X chromosome is randomly inactivated and becomes a barr body
- Ensures same amount of gene product as males
- Used for gender testing
- Tortoiseshell cat: all females, different coloured fur patches due to X inactivation
8
Q
What are quantitative characters?
A
- Characters that can be measured e.g. height
9
Q
What effect does environmental effects have on alleles
A
Phenotypic plasticity: ability of a genotype to produce more than one phenotype when exposed to different environments
