chapter 20 -22

Question 1

Evolution

Answer 1

Evolution is change in a population from one generation to the next of one or more heritable characteristics

Question 2

Biological Evolution

Answer 2

the change in inherited traits over successive generations in populations of organisms

Question 3

microevolution

Answer 3

changes among populations within a species over time

Question 4

macroevolution

Answer 4

refers to the formation of new species or groups of related species

Question 5

molecular evolution

Answer 5

studies evolutionary change at the level of DNA sequence

Question 6

species

Answer 6

a group of related organisms that share a distinctive form

Question 7

population

Answer 7

all members of a specie that live in the same area

Question 8

heritable trait

Answer 8

traits passed down from parent to offspring

Question 9

trait variation

Answer 9

diversity of a characteristic among individuals

Question 10

natural selection

Answer 10

a process that selects if a heritable traits is for the environment or against the environment. Only the fittest of animals and plants to survive and reproduce

Question 11

selective breeding

Answer 11

process that involves humans choosing two parents with beneficial traits to reproduce

Question 12

artificial selection

Answer 12

an evolutionary process in which humans select for or against particular features

Question 13

biogeography

Answer 13

study geographic distribution of extinct and living species

Question 14

convergent evolution

Answer 14

two different species becoming anatomically similar because they occupy similar enviorments

Question 15

analogous structures

Answer 15

features of different species that are similar in function but not in structure or do not derive from a common ancestor

Question 16

homologous structures

Answer 16

similar traits that occur due to descent from a common ancestor

Question 17

vestigial structure

Answer 17

biological structures that have no apparent function

Question 18

homologous genes

Answer 18

two genes that derive from the same ancestral gene

Question 19

orthologs

Answer 19

homologous genes that are found in different species

Question 20

paralogs

Answer 20

homologous genes within a single species

Question 21

vertical evolution

Answer 21

genetic changes occuring in a series of related species that form a lineage

Question 22

horizontal gene transfer

Answer 22

an organism incorporates genetic material from another organism without being the offspring of that organism

Question 23

True or False: An individual evolves through natural selection.

Answer 23

False

Question 24

A gene pool is

Answer 24

all the alleles for every gene in a given population.

Question 25

polymorphic gene

Answer 25

a gene that commonly exists as two or more alleles in a population

Question 26

monomorphic gene

Answer 26

a gene that exists as a single allele in a population

Question 27

SNP

Answer 27

single nucleotide polymorphism; a genomic variant at a single base in DNA

Question 28

allele frequency

Answer 28

number of allele copies of a specific allele in a population/ total number of all alleles for that gene in the population

Question 29

genotype frequency

Answer 29

of individual with a particular genotype in a population/ total number of individuals in the population

Question 30

In the Hardy-Weinberg equation, p and q represent __________ frequencies, while p2, 2pq, and q2 represent __________ frequencies.

Answer 30

allele; genotype

Question 31

adaptation

Answer 31

genetic changes in individuals for them to better suit the environment

Question 32

reproductive success

Answer 32

liklihood of an individual contributing fertile offspring

Question 33

fitness

Answer 33

the representation of an individual reproductive success

Question 34

directional selection

Answer 34

favors individuals at one extreme of a phenotypic distribution

Question 35

stabilizing selection

Answer 35

favors the survival of indivduals with intermediate phenotypes and selects those with extreme phenotypes

Question 36

diversifying selection

Answer 36

favors the survival of 2 or more genotypes that produce different phenotypes

Question 37

balancing slection

Answer 37

maintains genetic diversity in a population, two or more alleles are kept in balance

Question 38

heterozygote advantaged

Answer 38

the relative fitness of heterozygotes is higher than the relative fitness

Question 39

In plants, violet flower color (V) is dominant over white (v). If p = 0.8 and q = 0.2 in a population, what percentage of the flowers would you expect to be homozygous dominant (VV)? Assume this population is in Hardy-Weinberg equilibrium.

Hint: Calculate the genotype frequencies of the 2nd generation.

Answer 39

64%

Question 40

Polydactyly (being born with more than 5 fingers or toes) is caused by a dominant allele of a single gene. If the frequency of the recessive allele is 0.9 (or 90%) in a certain population, what percentage of the population would you expect to be heterozygotes? Assume this population is in Hardy-Weinberg equilibrium.

Note: In reality, there are other causes of polydactyly when it is accompanied by other disorders, so this problem is an over-simplification.

Answer 40

18%

Question 41

What might you conclude if allele or genotype frequencies of a population change from the expected values from generation to generation?

Answer 41

The population is not at equilibirum, it is evolving, and evolutionary forces are at play.

Question 42

In many species, the EPAS1 gene has been found to be involved in adaptation to life in high-altitude, low oxygen environments. This is true for several species of ducks that live in the Andes of South America. In Andean speckled teal duck populations, SNPs at locations 554, 603, and 651 within Exon 12 of the EPAS1 gene showed signatures of adaptation to life in high-altitude environments. However, yellow-billed pintail duck populations, also found in the Andes, showed adaptation at SNPs 595 and 628 within Exon 12 of the EPAS1 gene. This is an example of

Answer 42

convergent evolution

Question 43

Birds, bats, mice, and crocodiles all have four limbs (tetrapods). The ancestor of tetrapods evolved four limbs, and its descendents have inherited that feature from a common ancestor — so the presence of four limbs is an example of

Answer 43

a homologous structure (homology)