Unit 1, Evolution

Question 1

Meiosis

Answer 1

in gamete cells, four haploid daughter cells

Question 2

Mitosis

Answer 2

in somatic cells, two identical diploid daughter cells

Question 3

zygote

Answer 3

1 egg + 1 sperm cell fertilize

Question 4

mutation

Answer 4

change in nucleotide sequence

Question 5

chromosome

Answer 5

chain of DNA with stabilizing porteins

Question 6

random independent assortment

Answer 6

Metaphase 1, chromosomes randomly go to gametes

Question 7

Charles Darwin

Answer 7

went on 5 year voyage around the world, “evolution is ascent with modification”

Question 8

Darwinian Evolution

Answer 8

1. species accumulate differences
2. descendants differ from ancestors
3. new species arise from existing ones

Question 9

natural selection

Answer 9

Mechanism of evolution:
1. individuals have specific inherited characteristics
2. they produce more surviving offspring
3. pop. includes more individuals with inherited traits
4, pop. evolves to better adapt to environment

Question 10

Lamarck

Answer 10

acquired variation is passed on to descendants

ex: Giraffe’s necks lengthen during individuals lifetime (disproved)

Question 11

Hardy-Weinberg Principle

Answer 11

1. no mutation takes place
2. no gene flow is transferring to/from other sources
3. random mating is occurring
4. population size is very large
5. no selection occcurs

Question 12

homozygous

Answer 12

same alleles

Question 13

heterozygous

Answer 13

different alleles

Question 14

dominant allele

Answer 14

Allele that overtakes the other

Question 15

recessive allele

Answer 15

has to be homozygous recessive for the recessive phenotype to be expressed

Question 16

codominant

Answer 16

both genes expressed (speckled)

Question 17

incomplete dominance

Answer 17

trait is “mixed” (R + W = Pink)

Question 18

phenotype

Answer 18

the way gene is expressed

Question 19

genotype

Answer 19

the genetic makeup of the gene

Question 20

nonrandom mating

Answer 20

mating with specific genotypes, shifts genotypic frequency

Question 21

assortive mating

Answer 21

doesn’t change frequency of individual alleles, Increases proportion of homozygous individuals

Question 22

disassortive mating

Answer 22

phenotypically different individuals mate, produce excess of heterozygous

Question 23

founder effect

Answer 23

few individuals from original colony leave and found new population elsewhere

Question 24

bottleneck effect

Answer 24

drastic reduction in population, and gene pool size

Question 25

artificial selection

Answer 25

breeder selects for desired characteristics

Question 26

Fitness

Answer 26

1. survival 2. how often they mating 3. number of surviving offspring

Question 27

frequency-dependent selection

Answer 27

depends on how frequent a phenotype occurs in a population. (common trait = safe)

Question 28

positive frequency dependent selection

Answer 28

common phenotypes are favored; variation is eliminated from the population (uncommon trait = safe)

Question 29

oscillating selection

Answer 29

selection favors one phenotype at a time, shift in population average NOT individuals

Question 30

heterozygote advantage

Answer 30

keep deleterious alleles in a population, ex: sickle cell anemia

Question 31

high predation environment

Answer 31

males with drab colors are relatively small, reproduce at younger age

Question 32

low predation environment

Answer 32

bright coloration, increased spots, successful at defending territories

Question 33

pleiotrophy

Answer 33

sets limit on how much a phenotype can be altered

Question 34

absolute dating

Answer 34

age of fossils is estimated by rates of radioactive decay

Question 35

relative dating

Answer 35

position of the fossil in the sediment

Question 36

archaeopteryx

Answer 36

oldest known bird fossil

Question 37

homologous structures

Answer 37

structures with different appearances and functions that are all derived from the same ancestral feature

Question 38

vestigial structures

Answer 38

have no apparent function, but resemble structures their ancestors posessed

Question 39

extant

Answer 39

species currently living on Earth

Question 40

biogeography

Answer 40

study of geographic distribution of organisms

Question 41

convergent evolution

Answer 41

independent development of similar structures in organisms that aren't directly related

Question 42

marsupials

Answer 42

young are born in immature condition and held in pouch until they develop

Question 43

placentals

Answer 43

young aren't born until they can safely survive in external environment

Question 44

speciation

Answer 44

process by which new species arise: 1. transformation of one species to another 2. by splitting of one ancestral species into another

Question 45

sympatric speciation

Answer 45

differentiation of populations within a common geographic area into species: 1. phenotypically different 2. aren't distinct entities 3. utilize different parts of the habitat

Question 46

population

Answer 46

any group of individuals, usually of a single species occupying a given area at the same time

Question 47

subspecies

Answer 47

within a single species, individuals in population that occur in different areas may be distinct from one another

Question 48

geographic isolation

Answer 48

species occur in different areas, separated by river or mountain range

Question 49

ecological isolation

Answer 49

species in same area, but occupy different habitats

Question 50

behavioral isolation

Answer 50

species differ in mating rituals

Question 51

temporal isolation

Answer 51

species reproduce in different seasons/ time of day

Question 52

mechanical isolation

Answer 52

structural differences prevent mating

Question 53

prevention of gamete fusion

Answer 53

gametes from the separate species function poorly when they interact

Question 54

hybrid

Answer 54

post-zygotic, animal is sterile, ex: mule

Question 55

phermones

Answer 55

chemical signals

Question 56

reinforcement

Answer 56

incomplete isolating mechanism

Question 57

introregression

Answer 57

genes jumping from different species