Topic 37

Question 1

Forms of selection

Answer 1

Positive, negative, directional, disruptive, balancing,, automatic, counter selection

Question 2

Positive selection

Answer 2

increases the prevalence pf adaptive triats

Question 3

Negative selection

Answer 3

decreases the prevalence of adaptive traits

Question 4

Directional selection

Answer 4

occurs when natural selection favours a single phenotype and allele frequency continuously shifts in one direction

Question 5

Disruptive selection

Answer 5

(diversifying selection) describes changes in population genetics that simultaneously favours individuals at both extremes of distribution. Individuals contribute more offspring than ones in the middle

Question 6

Balancing selection

Answer 6

refers to forms of natural selection which work to maintain multiple alleles within a population

Question 7

Automatic selection

Answer 7

is when an advantageous charge happened in a trait non investigated

Question 8

Counter selection

Answer 8

when a disadvantageous change happened in a trait non investigated

to “fix” a negative trait, use counterselection to “fix” low milk prod in cow, to make its offspring have improved milk production in comparison.

Question 9

Selection index

Answer 9

a method of artificial selection in which several useful traits are selected simultaneously

Question 10

Correlation

Answer 10

the proportion of variance that two traits share due to genetic causes

may be positive or negative; possible to influence other traits