Pedigrees

Question 1

What is autosomal inheritance?

Answer 1

• autosomes (first 22 pairs of chromosomes)
• traits carried on autosomes
• genetic dominant and recessive traits

Question 2

What are sex-linked genotypes?

Answer 2

Phenotypes inherited through genes located in sex-chromosomes

Question 3

What are X-linked?

Answer 3

Recessive - probability of females ‘having disorder’ is very low (require 2x recessive alleles), e.g. hemophilia

Dominant - if father is affected, all females will have condition, e.g. vitamin D deficient Ricket’s

Question 4

What are Y-linked?

Answer 4

Y chromosome only has few genes; involved mainly in sex-determination and fertility, passed father to son; never shown in females