Lesson 9 - Genetics After Mendel

Question 1

Incomplete Dominance

Answer 1

Mendel had used the concept of dominance to
explain his results in pea plants, but there are many instances in nature where strict dominance does not apply

The heterozygous condition results in an intermediate phenotype – a “blend”

“red flowers + white flowers → pink flowers”

Question 2

Co – Dominance

Answer 2

A slightly different form of inheritance is observed in horses and cattle, where 2 alleles are expressed at the same time.

CO – DOMINANCE
- Neither allele is completely
dominant
- A “blend” does not exist

Question 3

Multiple Allelism

Answer 3

Geneticists have identified that it is possible to have more than 2 forms of a gene

This is called multiple allelism

This results in a larger number of possible genotypic combinations and a greater variety of phenotypes