Chapter 19

Question 1

What are the 4 assumptions used for Hardy Weinberg equations

Answer 1

1) Large population

2) All genotypes survive equally and are able to reproduce

3) Mating is Random

4) Mutations and migration are rare and can be ignored

Question 2

The HW law for allele frequencies

Answer 2

p + q = 1

p = frequency of dominant allele
q = frequency of recessive allele

Question 3

The HW law for genotype frequencies

Answer 3

p^2 + 2pq + q^2 = 1

p^2 = AA
2pq = Aa
q^2 = aa

Question 4

How to know if something is in genetic equilibrium?

Answer 4

If the allele frequencies of a gene remain constant from generation to generation

Question 5

As _____ genotype frequency decreases, ______ genotype frequency increases

Answer 5

homozygous, heterozygous

Question 6

Founder effect

Answer 6

A few individuals from a larger population start a new population with different allele frequencies

Question 7

Bottleneck

Answer 7

An event that dramatically reduces the the genetic diversity of a population

Question 8

Directional selection

Answer 8

Traits at only one phenotypic extreme are selected for or against

Question 9

Stabilizing selection

Answer 9

Intermediate phenotypes are favored, extremes are selected against

Question 10

Disruptive selection

Answer 10

Selection against intermediate phenotypes, both extremes are selected for

Question 11

Balancing selection

Answer 11

No single phenotype is favored. Diversity is maintained

Question 12

How does random assortment and recombination play a role in the population?

Answer 12

It created genetic diversity without introducing new alleles

Question 13

How do mutations play a role on the population?

Answer 13

Mutations can randomly generate new alleles, but they have little impact on allele frequency

Question 14

What are some forces that change allele frequencies?

Answer 14

Genetic drift, migration, and natural selection

Question 15

Genetic drift

Answer 15

Changed in allele frequency that occur randomly from generation to generation. Can be an increase or decrease

Question 16

Fitness

Answer 16

The likelihood that an organism will be able to survive and therefore reproduce

Question 17

Gene flow

Answer 17

Gene flow is any movement of individuals from one population to another (ex. Pollen being blown to new destination)

Question 18

Natural selection

Answer 18

Organisms that are more adapted to their environment are more likely to survive and pass on their genes.

Only one that increases the ability to survive and thrive! The rest are random!

Question 19

How does genetic variation impact the likelihood of survival?

Answer 19

The greater the genetic variation the less susceptible a population is to disease or environmental change, aka it INCREASES the likelihood of survival!

It allows populations to change easier too