Genotypic and Phenotypic Frequency

Question 1

sex-linked inheritance:

Answer 1

conditions passed down through families through one of the X or Y chromosomes

(only need to know about X linked conditions)

Question 2

Dominant inheritance:

Answer 2

occurs when an abnormal gene from one parent causes disease even though the matching gene from the other parent is normal

Question 3

Recessive inheritance:

Answer 3

when both genes in a pair must be abnormal for the person to exhibit symptoms of the condition

Question 4

Carriers (recessive inheritance):

Answer 4

an individual with only one defective gene in a pair

• although not affected with the condition, they can pass on the abnormal gene

Question 5

Autosomal inheritance:

Answer 5

conditions passed down through families on one of the 22 pairs of human autosomes (all chromosomes except the X and Y)

Question 6

Incomplete dominance:

Answer 6

occurs when the dominant allele does not dominate the recessive allele entirely; rather an intermediate trait appears in the offspring

Question 7

Co-dominance:

Answer 7

neither allele is recessive so the phenotypes of both alleles are expressed

Question 8

Complete dominance:

Answer 8

only one allele in the genotype is observed in the phenotype

Question 9

Pedigrees charts:

Answer 9

can be used to determine the inheritance pattern of a condition