Lecture 3

Question 0

What is simple dominance?

Answer 0

Phenotype shows either dominant or recessive
Not both
Not something in between

Question 1

What kinds of dominance are there?

Answer 1

Simple 
Incomplete
Co-dominance
Pseudodominance
Overdominance

Question 2

What makes one allele dominant and one recessive?

Answer 2

A gene which codes for enzyme activity is dominant

Question 3

What is incomplete dominance?

Answer 3

Dominant allele is not completely dominant over recessive allele ie. Hybrid offspring have intermediate phenotypes
The characteristics blend but the genetic material doesn’t
Eg. Snapdragon flower colour - pink flowers (Rr) have both red (R) and white (r) alleles
Next generation however can have any of the three colours of flower

Question 4

What is co-dominance?

Answer 4

Both products code for a product that works, but do different things
In a hybrid (heterozygote), both alleles are expressed equally
Eg. blood groups