Test 3, Deck 3

Question 1

In ducks and chickens, eggs of intermediate weight have more hatching success. What mode of selection is it?

Answer 1

Stabilizing selection

Question 2

Fossil evidence indicates that the average size of bears in Europe increased with each glacial period. What mode of selection is it?

Answer 2

Directional selection, one extreme favored

Question 3

Snails that live among tan rocks covered with white barnacles are either white or tan. Snails neither white nor tan or more likely to be eaten. What mode of selection is it?

Answer 3

Disruptive selection: 2 extreme favored

Question 4

Human newborns who are under 5 lb or over 10 lb are less likely to survive than babies between 5 lb and 10 lb. What mode of selection is it?

Answer 4

Stabilizing selection

Question 5

Finch bird population have variety of beak size/shape. In an island, the only food available in a drought was wood boring insects and seeds in cactus. Longer beaks could open the cactus seeds and wider beaks could strip off the tree bark. What mode of selection is it?

Answer 5

Disruptive selection

Question 6

Determine the frequency of the recessive alleles in a population with 20 AA, 100 Aa and 80 aa.

Answer 6

0.65

Question 7

Calculate q squared for a population with 100 AA, 40 Aa and 60 aa.

Answer 7

0.16

Question 8

Determine the frequency of dominant allele in 20 AA, 100 Aa and 80 aa.

Answer 8

0.35

Question 9

Calculate p squared for a population with 20 AA, 100 Aa and 80 aa.

Answer 9

0.12

Question 10

Determine the frequency of the homozygous dominant phenotype 40 AA, 60 Aa, 100 aa.

Answer 10

0.20

Question 11

Calculate p for population with 20 AA, 100 Aa, 80 aa.

Answer 11

0.3162

Question 12

determine the frequency of the homozygous recessive genotype in 100 AA, 40 Aa, 60 aa.

Answer 12

0.30

Question 13

Calculate q for a population of 20 AA, 100 Aa and 80 aa.

Answer 13

0.6325

Question 14

Calculate p+q for 60 AA, 100 Aa, 40 aa.

Answer 14

0.9952=1

Question 15

Which values need to be calculated to determine if population is in equilibrium.
A Real frequency of recessive allele
B Real frequency of homozygous recessive genotype
C p squared
D q squared
E Real frequency of dominant allele
F q

Answer 15

F, A, B

Question 16

In two parts in Africa, 90% elephants were slaughtered for their tusks, most female are now born without tusks. What is the mechanism of evolution?

Answer 16

Natural selection bc not random

Question 17

Ancestors of indigenous people arrived in small numbers by crossing the Bering strait. Type B blood is highest in Asia, but nearly absent in the indigenous population of America. What is the mechanism of evolution?

Answer 17

Genetic drift ( founder’s effect)

Question 18

How does a modification help an organism adapt?

Answer 18

The change in alleles will change the phenotype of the organism and it will be more fit to survive if the change is advantageous.

Question 19

How are different species determined?

Answer 19

Depends on the concept analyzed, Ecological: same ressources/area, Phylogenetic: same ancestry and genetics, Biological: same gene pool and able to interbreed and create fertile offsprings and Morphological: similar individuals

Question 20

What triggers change in allele frequency?

Answer 20

Gene flow, genetic drift, natural selection (change in environment) or mutations.