Week 7: Patterns and principles of heredity

Question 1

Describe the particulate theory of inheritance.

Answer 1

• Characters are distinct and hereditary determinants are particulate in nature
• Each adult has 2 genes for each character and these pairs segregate equally into gametes
• Fertilisation restores the pair randomly

Question 2

How does RNAi gene silencing work in nature?

Answer 2

• MicroRNAs act like RNAi and can regulate biological processes
• Has the potential to fight every disease

Question 3

What is incomplete dominance?

Answer 3

Heterozygotes show an intermediate phenotype

Question 4

What is co-dominance?

Answer 4

Heterozygotes show phenotype of both alleles

Question 5

What is pleiotropy

Answer 5

Interactions between alleles of a gene

Question 6

What is penetrance?

Answer 6

Measures the percent of individuals with a given genotype who exhibit the phenotype associated with the genotype

Question 7

What is expressivity?

Answer 7

Measures the extent to which a given genotype is expressed at the phenotypic level