Unit 7

Question 1

What happened to the finches that colonized the Galápagos Islands

Answer 1

They diversified and gave rise to new species

Question 2

Natural selection acts on

Answer 2

Traits that lead to survival and reproduction

Question 3

Organisms don’t evolve,…

Answer 3

Populations do!!

Question 4

Other term for evolution

Answer 4

Descent with modification

Question 5

What is natural selection

Answer 5

A process in which individuals that have certain traits tend to SURVIVE AND REPRODUCE at higher rates than other individuals because of those traits

Question 6

Natural selection also acts on

Answer 6

Phenotypic variations in populations

Question 7

“Fitness” is measured by

Answer 7

Reproductive success

Question 8

What are adaptations

Answer 8

Inherited characteristics of organisms that enhance their survival and reproduction

Question 9

2 observations that natural selection is based on

Answer 9

1 traits are heritable
2 more offspring are produced than can survive

Question 10

What does more offspring being produced than can survive mean?

Answer 10

There’s competition for limited resources which results in differential survival

Question 11

Favorable traits

Answer 11

Accumulate in the population

Question 12

What’s artificial selection

Answer 12

The selective breeding of domesticated plants and animals to encourage the occurrence of desired traits

Question 13

What’s a population

Answer 13

A group of individuals of the same species that live in the same area and interbreed to produce FERTILE offspring

Question 14

What’s the gene pool

Answer 14

A populations genetic makeup, consists of every type of allele

Question 15

Explain fixed alleles

Answer 15

If there is only one allele present for a particular locus in the population it is fixed; many fixed alleles = less genetic diversity

Question 16

Micro evolution

Answer 16

Small scale genetic changes in a population

Question 17

Evolution is driven by random occurrences like…

Answer 17

Mutations, Genetic Drift, Migration/Gene Flow, Natural Selection

Question 18

Mutations are

Answer 18

Changes in your nucleotide sequences that deviate from what is “normal”

Question 19

Mutations can result in

Answer 19

Genetic variation, they can form new alleles

Question 20

Mutation rates

Answer 20

Tend to be slow in plants and animals and high in prokaryotes due to fast generation time

Question 21

Most mutations are

Answer 21

Neutral or harmful

Question 22

What’s genetic drift

Answer 22

Chance events that cause a change in allele frequency from one generation to the next; most significant in small populations

Question 23

Why can genetic drift be bad?

Answer 23

It can lead to a loss of genetic variation and cause harmful alleles to become fixed

Question 24

Types of genetic drift

Answer 24

Bottleneck effect, founder effect

Question 25

Bottleneck effect is

Answer 25

When a large population is drastically reduced by a NON-SELECTIVE DISASTER (natural disasters, hunting); some alleles may become overrepresented, underrepresented or absent; if one allele survives over another it’s considered fixed

Question 26

What’s founder effect

Answer 26

When a few individuals become isolated from a large population and establish a new small population with a gene pool that differs from large population (lose genetic diversity)

Question 27

What’s gene flow

Answer 27

The transfer of alleles into or out of a population, alleles can be transferred between populations Ex: pollen being blown to a new location

Question 28

Directional selection

Answer 28

Selection towards one extreme phenotype

Question 29

Stabilizing selection

Answer 29

Selection towards the mean and against the extreme phenotypes

Question 30

Disruptive selection

Answer 30

Selection against the mean; both phenotypic extremes have the highest relative fitness

Question 31

Sexual selection

Answer 31

Explain why many species have unique/showy features; males have useless, potentially harmful structures that show they are good mates because they were able to survive at a disadvantage

Question 32

Hardy Weinberg Equilibrium is only good for populations that are

Answer 32

Not evolving!!!!

Question 33

What’s the purpose of Hardy Weinberg Equilibrium

Answer 33

Results can be compared with real data, if it is the same there is no evolving, if it is different there MAY BE evolving

Question 34

Conditions for Hardy Weinberg Equilibrium

Answer 34

1 no mutations 2 random mating 3 no natural selection 4 large population size 5 no gene flow

Question 35

What happens if a Hardy Weinberg equilibrium condition isn’t met?

Answer 35

Microevolution occurs

Question 36

Why is genetic variation good

Answer 36

The more genetic diversity, the better the population can respond to changes in the environment

Question 37

What happens to species with low genetic diversity

Answer 37

They are at risk of extinction