Altered Mutation Rate for Single-gene disorders

Question 1

The ____ is usually expressed as an incidence giving the number of mutations at a locus per million gametes produced per generation.

Answer 1

mutation rate ( μ )

Question 2

The _____ reflects the balance between the introduction of new mutant genes to the population & the loss of mutant genes from the population when an affected individual fails to reproduce.

Answer 2

mutant gene frequency

Question 3

If there is no impairment of reproductive capacity, then the ____ is normal (1 or 100%), whereas if reproduction is impossible, the ____ is zero.

Answer 3

biological fitness ( f )

Question 4

T/F. The impact of changes in the mutation rate on the frequency of a single - gene disorder depends upon the mode of inheritance

Answer 4

True.

Question 5

If the condition precludes reproduction (f = 0), then the birth frequencies for autosomal dominant, autosomal recessive and X - linked recessive conditions can be calculated to be ____, ____, and ____, respectively.

Answer 5

2μ; μ; 3 μ .

Question 6

Any change in the mutation rate will have most effect on an _____ & least on an _____.

Answer 6

X - linked recessive trait; autosomal recessive trait.

Question 7

Mutation rates are difficult to determine & most information relates to autosomal dominant traits & X – linked recessive traits w/ estimates of ____ mutations per million gametes per generation for different loci.

Answer 7

1 – 100 (average 10 – 20)