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Biology 1 (101-NYA-05) > unit test 2 (Ch.18-20) > Flashcards

unit test 2 (Ch.18-20) Flashcards

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1
Q

What are taxons?

A

A way to classify the diversity of organisms

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2
Q

What do taxons include?

A

kingdom-King
Phylum-Phillip
Class-Cried
Order-Out
Family-For
Genus-Good
Specis-Sex

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3
Q

How was it determined that the earth was a lot older than originally thought (Think James Hutton)?

A

erosion work over long periods of time in geology

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4
Q

What did Malthus identify?

A

That the human population could outgrow their supply of food

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5
Q

what was a consequence of Malthus’ claim?

A

population growth was slowed

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6
Q

what did Lamarck propose?

A

organisms could change over time based on 2 principles

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7
Q

what are the 2 principles that Lamarck proposed about the changing of organisms?

A

-Use and disuse
-Inheritance of acquired traits

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8
Q

What is an example of use and disuse of an organisms physical properties?

A

A giraffe’s neck could elongate if a food source was out of reach

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9
Q

How did Darwin come up with his claim that the earth is much older than we think?

A

-geologicl processes occur very slowly

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10
Q

What did Darwin say about populations and their food?

A

if populations grew faster than their food supply, this applied to animals as well. This could influence subsequent generations to be more suited to their environments.

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11
Q

What did the inheritance of traits from 1 generation to the next imply?

A

Organisms become better suited to their environments as the environments themselves change

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12
Q

Where did darwin find most of his evidence for adaptations, ‘inheritance characteristics that improve survival in an environment and increase reproductive success’?

A

Galapagos islands

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13
Q

What was the 2 main ideas of Darwin’s theory?

A

-Natural selection
Descent with modification

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14
Q

What are the pressures that Darwin considered on organisms in an environment ?

A

-resources are finite and limit population growth (next generation won’t thrive)
-Limited resources can lead to organisms to struggle to survive (Organisms will fight for their life)
-Characteristics of individuals in a population vary greatly (no one is exactly the same in characteristics)
-Not all individuals in a pop. will reproduce succesfully (organisms better suited to their environment –> leave behind better offspring more suited to their environment = Fitness)

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15
Q

what does fitness mean in evolution?

A

Reproductive success of an individual

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16
Q

Greater fitness means that the organism will leave…

A

More offspring tha individuals that display less fitness

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17
Q

Over generations, traits providing adavantages in a given environment will accumulate in a population. What is this called?

A

natural selection = survival of the fittest

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18
Q

What does it mean when the generations are slightly different that the genrations before that?

A

descent with modification

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19
Q

does evolution work on individuals?

A

No only on populations

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20
Q

does evolution act on traits that aren’t heritable?

A

No only heritable traits

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21
Q

what is an example of evidence for evolution?

A

Soapberry bugs feed on fruit with the help of beak length
-If beak length is variable and heritable, we might expect beak length to vary in 2 populations (1 in south Florida and 1 in central Florida) which they do!

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22
Q

what is homology?

A

describes a characteristic that is similar between organisms as a result of common ancestry

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23
Q

What causes the characteristics of organisms to be no longer identical?

A

adaptive radiation

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24
Q

what is adaptive radiation?

A

where organisms evolve and adapt to new environments, causing modifications to original characteristics.

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25
Q

what is an example of adaptive radiation?

A

human, cats, whales and bats all display similar bones in their limbs; humerus, ulna, radius, carpals, metacarpals..

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26
Q

what is an example of homologous structures?

A

embyos of varius animal species;
embryos of fish, amphibians, reptiles and mammals display **similar structures early in development **which develop into homologous structures in adulthood

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27
Q

what are analogous structures?

A

characteristics that are similar between unrelated organisms

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28
Q

do analogous structures evolve from common ancestry?

A

no, they eveolve from similar selective **pressures **from their environment

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29
Q

What is an example of analogous structures?

A

the wings of bats, birds, and insects:
common ancestors of these organisms did not have wings but* selective pressures* in the environment caused them to evolve wings

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30
Q

What was Pangaea?

A

Supercontinent, all continents put together

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31
Q

what supports the theory of Pangaea?

A

Fossil record and carbon dating these fossil

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32
Q

what is a population?

A

all individuals of the same species that live in a particular place at the same time

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33
Q

do individuals in a population vary in their traits?

A

yes

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34
Q

how does variation occur in a population?

A

selective pressures from the environment and** inheritance of genes**

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35
Q

how is evolutionary change inherited?

A

1 generation to the next

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36
Q

what do individuals of a population share? (think genetics)

A

same number of genes

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37
Q

since there is a lot of variation in populations and individuals in a population share the same number of genes, what is an important cause of the variation which is linked to their genes?

A

alleles

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38
Q

what is a gene pool?

A

all alleles for all genes present in a population

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39
Q

True or False? diploid organisms can have 3 alleles for each gene

A

no, it can only have up to 2 alleles

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40
Q

do the 2 alleles of diploid organisms represent all the possible alleles for a gene?

A

no, there are more possible alleles for that gene

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41
Q

what is microevolution?

A

Includes
-creation of new alleles from mutations
-the change in proportions of alleles in a population’s gene pool from 1 generation to the next

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42
Q

what is a basic (easy) defenition of microevolution?

A

if proportion of individuals of any genotype changes from 1 generation to the next

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43
Q

what is genotype frequency?

A

proportion of a specific genotype in population
Ex: there are 490 individuals with the genotype AA in a population of 1000 so the genotype frequency is 0.49

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44
Q

what is an allele frequency?

A

proportion of a specific allele in a population
Ex:
-490 AA
-420 Aa
so 490 x2 + 420=1400
total number of alleles in this population is 2000 (All A & a’s)
allele frequency = 1400/2000= 0.7

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45
Q

What does it mean if the allele frequency is changing over generations?

A

evolution is occuring

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46
Q

how do allele frequencies change?

A

influence of outside factors

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47
Q

what does Hardy-Weinberg Principle explain?

A

if allele & genotype frequencies do NOT change over time, population is NOT evolving

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48
Q

what do we say if there is no change in allele or genotype frequency?

A

populaion is at equilibrium and NOT evolving

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49
Q

Is it rare for a population to be in Hardy-Weinberg equilibrium?

A

Yes, because microevolution includes ANY force or pressure that could CHANGE proportion of alleles or genotypes in 1 generation to the next

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50
Q

what could prevent a population from evolving? (5)

A

-no mutations
-Random mating
-No natural selection
-having an extremely large population size
-no migration (transfer of alleles from another population)

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51
Q

What does ‘p’ represent in H-W equation (p+q=1)

A

p= frequency dominant allele

52
Q

what does ‘q’ represent in H-W equation (p+q=1)

A

q= frequency of recessive allele

53
Q

Say there is
-320 C^RC^R
-160 C^RC^W
-20 C^WC^W
what is ‘p’ in H-W equation?
C^R is the dominant allele…

A

p= frequency of dominant allele
320x2 (C^RC^R)=640
+160(C^R)
=800/1000 (pop.)
=0.8 is ‘p’

54
Q

what is p^2 in the H-W equation
(p^2 + 2pq + q^2 = 1)

A

p^2 = AA freq
(homozygous dominant)

55
Q

what is ‘pq’ in H-W equation ?
(p^2 + 2pq + q^2 =1)

A

pq= Aa freq
(heterozygous)

56
Q

what is ‘q^2’ in the H-W equation?
(p^2 + 2pq + q^2 =1)

A

q^2= aa freq
(homozygous recessive)

57
Q

What equation do we use for the allele frequencies for a gene with only 2 alleles?

A

p + q =1

58
Q

what type of equation do we use for expected genotype frequencies?

A

p^2 + 2pq + q^2 =1

59
Q

what factors cause microevolution? (5) (think opp of what causes no variation through generations)

A

-Mutations
-Choice of mating partners
-natural selection
-Genetic drift
-Gene flow from migration

60
Q

what do mutations cause?

A

changes in genetic sequences –> new alleles

61
Q

what does natural selection cause?

A

selects best suited individuals (survival of the fittest)

62
Q

What does fitt mean in evolution terms?

A

best suited individuals will often be chosen for mating because they create better offspring

63
Q

what is the cause of genetic drift?

A

a random sample of a small group of organisms from a large population

64
Q

what is the cause of gene flow?

A

flow of alleles into or out of a population VIA** migration**

65
Q

what is sexual recombinations?

A

produces new combinations of alleles–> produce genetic variation that natural selection relies on

66
Q

if in 1 generation the allelic frequency is 0.7 for genotype C^R and changes in generation 2 to 0.5 then to generation 3 being 1, what type of factor is causing this type of evolutionary change?

A

genetic drift

67
Q

what are 2 examples of genetic drift?

A

-Bottleneck effect
-Founder’s effect
Both randomly change the frequency of alleles

68
Q

true or false? Genetic drift simply randomly selects individuals from a larger population to continue perpetuating species

A

true

69
Q

what is the bottleneck effect?

A

genetic drift example that happens when the number of individuals in a larger population is drastically reduced by a disaster.

70
Q

what is the founder’s effect?

A

genetic drift example that happens when individuals become **isoalted from a larger population **

71
Q

Does gene flow cause a population to gain alleles or lose?

A

Both. 1 population might gain some and the other might lose Vise-versa

72
Q

In gene flow, what does the mixing of individuals from different populations result in?

A

reduces differences between populations over time

73
Q

what is the only factor that can cause adaptive evolution?

A

**natural selection **leads to **adaptation **of an organism to it’s environment

74
Q

what is macroevolution?

A

combination of positive mutations and natural selection

75
Q

will natural selection create entirely new genotypes?

A

no, it will only increase the frequencies of certain genotypes

76
Q

true or false? natural selection increases the frequency of beneficial alleles?

A

yes

77
Q

how does natural selection increase the frequency of beneficial alleles?

A

1-beneficial alleles arise due to a mutation
2-natural selection occurs –> proportion of alleles in gene pool increase
3-Beneficial allele eventually replace all other alleles in a population

78
Q

what is a negative selection?

A

natural selection that decreases frequency of harmful allele

79
Q

what is a positive selection?

A

natural selection increases the frequency of a favorable allele

80
Q

what effects can natural selection have on the distribution of phentoypes in a population? (3)

A

-directional selection
-disruptive selection
-stabilizing selection

81
Q

what is directional selection?

A

-shifts a population’s phenotypic traits in 1 direction or the other of a curve
-population’s environment changes or members of a population migrate to new habitat.

82
Q

an example of directional selection?

A

resistance of microbes to antibiotics: Antibiotics selects for microbes that already have resistance which make the bacteria multiply and thrive..not good

83
Q

what is Disruptive selection?

A

when conditions favor individuals at both extremes of phenotypic range for example
small-billed birds feed on soft seeds but large-billed birds specialize in cracking hard seeds

84
Q

What is stabilizing selection?

A

conditions act against both extreme phenotypes and **favours intermediate **variants

85
Q

out of the 3 selections, which reduces variation?

A

stabilizing selection

86
Q

what is speciation?

A

process of which 1 species **splits into 2 or more new species

87
Q

what is marcoevolution?

A

evolutionary change above species level over long periods of time

88
Q

what does evolutionary theory explain?

A

how new species originate in addition to how populations evolve

89
Q

what is a species? (think a human and a cat)

A

individuals that can breed with eachother in nature to produce viable offspring

90
Q

what does the biological species concept emphasize?

A

reproductive isolation

91
Q

what causes memebers of common species to not be able to reproduce with eachother?

A

reproductive barriers

92
Q

what are the 5 types of prezygotic barriers? (zygote never produced)

A

-habitat isolation
-temporal isolation
-behavioral isolation
-mechanical isolation
-gametic isolation

93
Q

why can’t the common species mate if habitat isolation is implied? (prezygotic)

A

because the 2 species occupy different habitats so they can’t mate

94
Q

why can’t 2 common species mate when temporal isolation is implied? (prezygotic)

A

the 2 species breed during different times of the day, month, years so the species can’t mate

95
Q

why can’t 2 common species mate when behavioral isolation is implied?

A

because the 2 species mating calls/ rituals don’t attract eachother

96
Q

why can’t 2 common species mate when mechanical isolation is implied?

A

the 2 species **cannot physically have sex **because of morphological differences.

97
Q

why can’t 2 common species mate when gametic isolation is implied?

A

sperm of 1 species cannot fertilize eggs of another species

98
Q

what are the 3 postzygotic barriers?

A

-reduced hybrid viability
-reduced hybrid fertility
-hybrid breakdown

99
Q

what is reduced hybrid viability? (postzygotic)

A

genes of different parent species interact in ways that impair hybrid’s development or survival

100
Q

what is reduced hybrid fertility?

A

hybrids are healthy but sterile (can’t reproduce)

101
Q

what is hyrbid breakdown? (postzygotic)

A

1st generation hybrids= viable and fertile
but when they mate, they can’t produce offspring that will be able to reproduce

102
Q

how can we define a species? (3)

A

-morphological species concept
-ecological species concept
-phylogenetic species concept

103
Q

what does the morphological species concept define?

A

characterizes a species by it’s body shape, size and structural features

104
Q

how does an ecological species concept define a species?

A

views species in terms of it’s ecological niche

105
Q

how does phylogenetic species concept define a species?

A

phylogenetic history of organisms

106
Q

how does speciation occur?

A

reduced gene flow

107
Q

what are the 2 ways gene flow is reduced?

A

-allopatric speciation
-sympatric speciation

108
Q

what is allopatric speciation?

A

geographic separation of populations which restricts gene flow (genes in and out of a population)

109
Q

what is sympatric speciation?

A

geographically overlapping populations when biological factors like chromosomal changes and non random mating reduce gene flow.

110
Q

is there physical separation in sympatric speciation?

A

no, a population experiences different selective pressures without physical separation.

111
Q

how does sympatric speciation occur? (2 ways)

A

-change in behavior
-change in habitat (niche with same geographic area)

112
Q

what does sexual selection help?

A

maximize reproductive success

113
Q

what are the 3 types of sexual selection?

A

-intersexual selection
-intrasexual competition
-mate choice

114
Q

what is intersexual selection?

A

selects features that make an organism more attractive to the opposite sex

115
Q

what is intrasexual competition?

A

selects features that help an individual intimidate or** fight off same-sex rivals**

116
Q

what is mate choice? (like a dating show)

A

selection of nonrandom process in which females select males based on a certain appearance

117
Q

What is the handicap theory? (think of how hard it must be to raise a handicap kid)

A

they are indicator traits that suggest their features are condition-dependent and have a cost. If individuals can handle the cost, it can suggest superior genetic quality

118
Q

What is the Hamilton-Zuk hypothesis?

A

an extension of the handicap theory that posits **sexual ornamnets **are indicators of parasite and **disease-resistance **

119
Q

what gender is intrasexual competition more apparent in?

A

male-male features = competition for the female

120
Q

can speciation cause major changes in physical appearances over time?

A

yes

121
Q

can natural selection anticipate future environments by selecting for characters that will suit a future environment?

A

no,

122
Q

what is evolutionary novelties?

A

changes in genetics lead to phenotype changes which lead to changes in adult phenotypes.

123
Q

what can evolutionary novelties arise from?

A

-gradual refinement of existing structures
-major changes in body can result in developmental **genes **or genes that control spatial organization of body parts

124
Q

how are mutations in genes that control spatial organization formed?

A

products of 1 class of genes; Hox genes = provide positional information in an animal embryo

125
Q

what happens if Hox genes are duplicated?

A

1 gene will continue coding for proteins that regulate normal development

126
Q

what could happen if further mutations were to happen to these hox genes?

A

can give rise to new physical features

Biology 1 (101-NYA-05) (9 decks)

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