Module 4 Population genetics

Question 1

a group of individuals of the same species that live in the same area and interbreed (interbreeding causes production of fertile offspring)

Population genetics is the study of the variation in alleles and genotypes within the ___, and how this variation changes from one generation to the next.

Answer 1

POPULATION

Gene Pool

Question 2

Assumptions of the HW model:
1. Organism is ____
2. Reproduction is ____
3. Generations are ____
4. Mating occurs at ____
5. Population size is____
6. Migration is zero.
7. Mutation is zero.
8. Natural selection does not affect the gene in question.

Answer 2

Assumptions of the HW model:
1. Organism is diploid.
2. Reproduction is sexual.
3. Generations are non-overlapping.
4. Mating occurs at random.
5. Population size is very large.
6. Migration is zero.
7. Mutation is zero.
8. Natural selection does not affect the gene in question.

Question 3

Factors that affect in Gene Frequencies: (6)

Answer 3

a. mutation
b. selection
c. migration
d. genetic drift
e. environmental diversity
f. non-random mating patterns

Question 4

the primary source of new alleles in a gene pool. It is a
permanent change in the DNA sequence that makes up a gene.

It is considered as the ultimate source of genetic variation and therefore of evolution

Answer 4

MUTATION:

Question 5

n many cases, the effects of natural
selection on a given allele are ____. The allele either confers a selective advantage, and spreads throughout the gene pool, or it confers a selective disadvantage, and disappears from it.

Answer 5

directional.

Question 6

In other cases, however, selection acts to preserve multiple alleles within the gene pool and a balanced
equilibrium is observed. This situation, labelled ___, can arise because of a selective advantage for individuals heterozygous for a given allele.

Answer 6

balanced
polymorphism

Question 7

____ ability to survive in an environment long enough to reproduce. It also refers to the fitness of a genotype

Answer 7

RELATIVE FITNESS

Question 8

selects against the average individual in a population ex. medium colored moths

favors the intermediate variants ex. robin eggs, butterflies, baby weight

an extreme phenotype is favored over other
phenotypes, causing the allele frequency to shift over time in the direction of that phenotype ex. horse size and dark moths

Answer 8

Disruptive selection

Stabilizing selection

directional selection

Question 9

occurs as the result of random fluctuations in the transfer of alleles from one generation to the next, especially in small populations

reduces variation

ex. Bottleneck effect and founder effect

Answer 9

Genetic drift

Question 10

If two populations of a given species
become genetically distinct enough that they can no longer interbreed, they are regarded as new species

Answer 10

speciation

Question 11

mate choice is independent of phenotype and
genotype

changes genotype frequency but not allele
frequency

mate choice is dependent on similarity of
phenotype

mate choice is dependent on dissimilarity
of phenotype

Answer 11

Random mating

Non-random mating

Positive Assortment

Negative Assortment