Ch.23

Question 1

Define alleles

Answer 1

A particular version of a gene

Question 2

Define genotype

Answer 2

 Refers to the genetic material past between generations

Question 3

Define phenotype

Answer 3

The Observable traits of an individual

Question 4

What does nonrandom mating only change

Answer 4

It onlychanges genotype frequencies NOT allele frequencies

Question 5

What does inbreeding do to alleles

Answer 5

Homozygosity of alleles increase but heterozygosity of alleles decrease

Result in less fitness and recessive alleles will represent loss of function in an organism

Question 6

Define inbreeding depression

Answer 6

Is a decline in avg, fitness that takes place when homozygosity decreases in a population

Question 7

What evolutionary process only produces adaptation?

Answer 7

Natural selection

Question 8

Define directional selection

Answer 8

Changes avg. Phenotype in pop. In one direction

Effect on phenotype: cause change in avg phenotype of a pop.

Genetic variation is reduced

Question 9

Define stabilizing selection

Answer 9

Form of natural selection where individuals with moderate or avg phenotypes are more fit

Question 10

Define disruptive selection

Answer 10

A type of natural selection that actively selects against the intermediate in a population favoring both extremes of the spectrum

Question 11

Define balancing selection

Answer 11

This type of natural selection that maintains genetic variation for longer than expected

Question 12

Define sexual selection

Answer 12

Is a form of nonrandom mating that occurs when females choose certain males or males competition

It leads to change in allele frequencies

Question 13

Define intersexual selection

Answer 13

Is a type of sexual selection inwhich an individual of one sex chosen a particular individual of other sex for matching

Question 14

Define intrasexual selection

Answer 14

A type of sexual selection driven by competition among members of one sex (male v male)

Question 15

Define founder effect

Answer 15

Occurs when a group establishes a new pop. In a new area. This change alleles frequencies

Question 16

Define population Bottle necks

Answer 16

Sudden decrease in pop-size in a once large pop., that are caused by disease or natural catastrophes

Question 17

What does gene flow do?

Answer 17

Is the random movement of alleles between pop.

That then equalized allele frequencies

Question 18

gene flow occurs when

Answer 18

Individuals leave one population join another and breed

Question 19

Define mutation

Answer 19

Any permanent change in the hereditary material of an organism and is the only source of new alleles in a population and modifies allele frequencies by continually introducing new alleles

Question 20

Does a mutation occur by chance?

Answer 20

Yes, and only by chance

Question 21

what is the ultimate source of genetic variation ?

Answer 21

Mutations

Question 22

Are mutations random?

Answer 22

Yes

Question 23

Does genetic drift decrease genetic diversity?

Answer 23

Yes, over time

Question 24

Does gene flow increase genetic diversity? Is there any exceptions?

Answer 24

Yes it does, but it can also decrease variation of the source of population if alleles leave with the moving population

Question 25

Define point mutation

Answer 25

Before chromosome level mutation

Question 26

Key points of genetic drift

Answer 26

- Genetic drift is random with respect to fitness - genetic drift is most pronounced in small populations - overtime genetic daft can lead to the random loss or fixation of alleles

Question 27

Define sexual dimorphism

Answer 27

Refers to any trait that differs between males and females of same species include: -Weaponry deer ex antlers on males - ornamentation and behavior in courtship ex peacocks colorful male feathers - body size

Question 28

What is heterozygote advantage?

Answer 28

Pattern of natural selection that favors heterozygous individuals compared to homozygous individuals. Promotes genetic variation forming balancing selection

Question 29

Define deleterious alleles

Answer 29

Allele that reduces an individuals fitness

Question 30

What does inbreeding increase?

Answer 30

Homozygosity which makes offspring have lower fitness

Question 31

The assumptions of the Hardy- Weinberg principle

Answer 31

1. Random mating- no mate choice; gametes combine randomly 2. No natural selection- all individuals contribute equally to gene pool 3. No genetic drift- random allele frequency changes) 4. No gene flow - no new alleles added or lost from gene pool 5. No mutations - no new alleles introduced into gene pool

Question 32

Define gene pool

Answer 32

alleles from all gametes and each generation go into a single group then combine randomly This concept was first brought up by Hardy and Weinberg

Question 33

What four processes is known to drive evolution?

Answer 33

1. natural selection 2. Genetic drift 3. Gene flow 4. Mutation

Question 34

Alleles that reach a frequency of 1.0 are said to be

Answer 34

Fixed

Question 35

Deleterious alleles are said to be

Answer 35

Lost at a 0.0

Question 36

Natural selection

Answer 36

Increases the frequency of alleles that contribute to reproductive success in a particular environment

Question 37

Genetic drift

Answer 37

causes allele frequencies to change randomly

Question 38

The 5 important assumptions of the hardy Weinberg principle

Answer 38

1. Random mating- no mate Choice gametes combine randomly 2.  No natural selections- all individuals contribute equally to gene pool 3. No genetic drift - (random allele frequency changes) - alleles not picked by chance because it assumes population is large 4. No gene flow - no new alleles added or lost from gene pool 5. No mutations- no new alleles introduced into gene pool

Question 39

Given a population Of 100 individuals where 15 AAand 25 Aa and 60 aa what is the frequency of allele “A” and the frequency of alleles ”a”

Answer 39

Question 40

The Hardy Weinberg equation

Answer 40

P^2+2pq+q^2=1

Question 41

4 processes of evolution

Answer 41

Natural selection Genetic drift Gene flow Mutation

Question 42

Natural selection

Answer 42

Increases the frequency of alleles that contribute to reproductive success in a environment

Question 43

Genetic drift

Answer 43

Causes allele frequencies to change randomly Can lead to random loss or fixation of alleles Thy can result to decrease in genetic variation

Question 44

Gene flow

Answer 44

Occurs when individuals leave one pop., join another, and breed

Question 45

Mutation

Answer 45

Modifies allele frequencies by continually introducing new alleles

Question 46

Natural selection occurs in what 4 patterns?

Answer 46

1. Directional selection 2. Stabilizing selection 3.disruptive selection 4. Balancing selection

Question 47

Question 48

4 processes of evolution

Answer 48

1. Natural selection 2. Genetic drift 3. Gene flow 4. Mutation