b51 midterm 2

Question 1

what are the three molecules that are important for evolution?

Answer 1

protein

DNA

RNA

Question 2

an essential macromolecule for all known forms of life. ______ are three-dimensional biological polymers constructed from a set of 20 different monomers called amino acids

Answer 2

proteins

• most of the dry weight of a cell is composed of proteins
• give cell most of its structure
• carry out many of the chemical reactions essential for life
• there are 100 000 kinds of proteins that make up the human body but they come from a combination of 20 different amino acids

Question 3

DNA is composed of compounds called

Answer 3

nucleotides

Question 4

the structural unit that links together to form DNA (and RNA).

each ______ includes a sugar (like deoxyribose) and a base

Answer 4

nucleotide

Question 5

any change to the genomic sequence of an organism

Answer 5

mutation

• may generate heritable changes to the sequence of bases in molecules of DNA
• can alter structure, physiology, or behaviour of organisms
• they can be deadly or benign (not harmful in effect)

Question 6

do all living things use DNA as their genetic material?

Answer 6

no most do except RNA viruses which hijack DNA bearing cells to replicate themselves

Question 7

a group of interacting and potentially interbreeding individuals of a species

Answer 7

population

• some populations span large geographic ranges while some occupy only small ranges and are isolated from other populations of the same species
• made up of individuals and those individuals carry alleles

Question 8

the study of allele distributions and frequencies is known as

Answer 8

population genetics

Question 9

study the patterns of allelic diversity in populations and how these patterns change over time

Answer 9

population genetics

Question 10

refers to the combination of alleles carried by an individual at a particular genetic locus, or just a few loci

Answer 10

genotype

Question 11

because diploid organisms carry two copies of each autosomal chromosome, they can have up to _____ alleles for each gene or locus

Answer 11

two

Question 12

individuals carrying two different alleles are _______ for the locus

Answer 12

heterozygous

Question 13

individuals carrying two copies of the same allele are ____ at the locus

Answer 13

homozygous

Question 14

is a type of phenotypic plasticity where a single genotype can produce multiple distinct phenotypes in response to environmental cues.

Answer 14

polyphenism

Question 15

group of individuals of same species living in the same area

Answer 15

population

• interbreed, producing fertile offspring

Question 16

study of processes that change allele and genotype frequencies in populations

Answer 16

population genetics

Question 17

versions of genes

Answer 17

alleles

Question 18

combinations of alleles possessed by individuals

Answer 18

genotypes

Question 19

observable traits

Answer 19

phenotypes

Question 20

change in allele frequencies are driven by what four processes?

Answer 20

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

Question 21

modifies allele frequencies by continually introducing new alleles

Answer 21

mutation

Question 22

causes allele frequencies to change randomly

Answer 22

genetic drift

Question 23

all alleles from all gametes go into a single group

Answer 23

gene pool

Question 24

what is the Hardy Weinberg theorem based on

Answer 24

gene pool concept

Question 25

what does the Hardy-weinberg theorem act as

Answer 25

a null hypothesis Hardy-Weinberg theorem predicts that allele frequencies will NOT change in the absence of drift, selection, mutation, and migration

Question 26

the study of how and why allele frequencies change

Answer 26

Population genetics

Question 27

allelic effects can be predicted by summing number of copies present

Answer 27

additivity

Question 28

dominant allele masks presence of recessive allele in heterozygotes

Answer 28

dominance

Question 29

moving alleles between population

Answer 29

gene flow also called migration

Question 30

what is the only mechanism that leads to adaptation

Answer 30

natural selection

Question 31

mendelian genetics approach breeds two individuals that are

Answer 31

heterozygous Aa x Aa

Question 32

what is the fundamental equation of the Hardy Weinberg Principle

Answer 32

p2 + 2pq + q2 =1

Question 33

when no change in allele frequencies

Answer 33

Hardy-Weinberg equilibrium - allows us to predict future frequencies **when alleles are transmitted via meiosis and random combination of gametes, the allele frequencies do not change, genotype frequencies may change but not allele frequencies

Question 34

genetic drift has significant evolutionary effects in what size of populations

Answer 34

genetic drift has significant evolutionary effects in SMALL populations

Question 35

probability of an allele surviving a bottleneck depends on

Answer 35

1. frequency of allele before bottleneck 2. severity of bottleneck (i.e. number of surviving)

Question 36

survival and reproductive success of an individual with particular phenotype

Answer 36

biological fitness

Question 37

beneficial effects for one trait but detrimental effects for another trait of that gene

Answer 37

antagonistic pleiotropy

Question 38

multiple phenotypic traits associated with single gene

Answer 38

pleiotropy

Question 39

selection is more powerful in ______ populations

Answer 39

large

Question 40

does selection act on additivity of dominance

Answer 40

additivity

Question 41

some forms of selection can maintain diversity in population

Answer 41

balancing selection

Question 42

common phenotypes selected against; rare phenotypes are favoured

Answer 42

Negative frequency dependent selection:

Question 43

measure of population differentiation

Answer 43

FST

Question 44

study of genetic mechanisms and evolution of continuous, complex phenotypic traits

Answer 44

Quantitative genetics

Question 45

Simple/discrete traits

Answer 45

qualitative

Question 46

Complex traits

Answer 46

quantitative

Question 47

proportion of the total phenotypic variation of a trait that is attributable to genetic differences among individuals

Answer 47

Broad sense heritability (H2):

Question 48

the component of variance that causes offspring to resemble their parents and causes populations to evolve predictably in response to selection

Answer 48

narrow sense heritability

Question 49

allele at one locus is independent of presence or absence of allele at second locus

Answer 49

Linkage equilibrium (LE)

Question 50

allele at one locus is non randomly associated with the presence or absence of allele at second locus

Answer 50

Linkage disequilibrium (LD)

Question 51

group of functionally related genes close enough to segregate as a unit

Answer 51

supergene

Question 52

Phenotypes vary depending on environment

Answer 52

Phenotypic plasticity:

Question 53

tracking history of alleles through time

Answer 53

coalescence

Question 54

what is responsible for most molecular evolution

Answer 54

drift (said by the neutral theory of molecular evolution)

Question 55

Amino acid sequence of the protein is unchanged - Often selectively neutral

Answer 55

Synonyms (silent) mutation:

Question 56

Amino acid sequence of the protein is changed Likely subject to selection

Answer 56

Nonsynonymous (replacement) mutation

Question 57

do nonsynonymous and synonymous mutations evolve at different rates if so which is faster

Answer 57

they evolve at different rates synonymous mutations evolve faster (because of drift) nonsynonymous mutations evolve slower because they are acted on by selection

Question 58

the elimination of polymorphism near a beneficial mutation that has spread to fixation

Answer 58

Selective sweep

Question 59

rate of nonsynonymous to synonymous substitutions

Answer 59

dN/dS

Question 60

does selection act on the population or the individual

Answer 60

individual

Question 61

Upstream section of DNA

Answer 61

gene control region, sometimes the promoter region, influences transcription

Question 62

Acts like a light switch- turns sequences on or off

Answer 62

transcription factor

Question 63

how are hox gene arranged

Answer 63

hierarchical, arranged in order of expression

Question 64

capable of carrying out more than 1 function are especially likely to take on new functions if duplicated

Answer 64

Pleiotropic genes

Question 65

homologous gene arising from gene duplication

Answer 65

Paralog

Question 66

homologous gene in different species that originated in common ancestor

Answer 66

Ortholog

Question 67

co-option of gene or network for novel function as result of mutation

Answer 67

Gene recruitment

Question 68

what event happened first in the evolution of snake venom?

Answer 68

duplication of the defensin gene

Question 69

the condition that occurs when a mutation that causes beneficial effects for one trait also causes detrimental effects on other traits is called

Answer 69

antagonistic pleiotropy