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BIO 102-General Biology 2 EC > Unit One- Evolution (Chp. 16, 17, 18) > Flashcards

Unit One- Evolution (Chp. 16, 17, 18) Flashcards

1
Q

Evolution

A

change occurring in a line of decent over time

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2
Q

Evolution may occur due to:

A

Natural Selection
Artificial Selection

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3
Q

Natural Selection

A

found in nature

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4
Q

Artificial Selection

A

impacted by man or mans activities

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5
Q

We know Evolution Exists by the study of:

A

Anatomy
Embryology
Biogeography
Molecular Biology

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6
Q

We know Evolution exists by the presence of:

A

Genetic variation within species
Transitional forms in fossil record
Imperfection and vestigial structures
Antibiotic resistant bacteria

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7
Q

Individuals of a population vary in __, ___, __, due to genetic differences which are heritable

A

Form, function, and behavior

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8
Q

Some traits (defined by genetics) are ____ ____ to the changing environment than others

A

More Adaptive

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9
Q

More offspring are produced than are able to survive so resources for survival and reproduction are ___

A

Limited

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10
Q

Inherited characteristics that allow offspring to best compete for limited resources will survive and reproduce have variations that are _____ favorable.

A

More

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11
Q

Results of differences in _____ and _____ leads to Natural Selection

A

Survival
Reproductive rates

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12
Q

Over time, Natural selection produces organisms that are “better fit” for the prevailing conditions, meaning

A

“Survival of the Fittest”

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13
Q

A population

A

a group of individuals of the same species that live in an area in which they can survive and interbreed

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14
Q

a ___ evolves, NOT an _____

A

population
individual

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15
Q

Evolution can only occur if there is _____

A

Variation (could refer to genes, nature or both)

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16
Q

An Adaptation

A

a heritable trait that helps the survival and/or reproduction of an organism in its present environment
(ex. white winter coat of an artic fox)

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17
Q

Charles Darwin

A

a naturalist who was part of a survey expedition and proposed the idea of evolution and natural selection in his book On The Origin of Species

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18
Q

Alfred Wallace

A

studied wildlife and independently came to the same conclusion of Darwin and presented his hypothesis in 1858

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19
Q

What causes Genetic Variation?

A

different alleles of shared genes are the basis of variation within a population

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20
Q

Dimorphic traits

A

traits with two distinct forms
(ex. purple and white flower colors in pea plants)

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21
Q

Polymorphic traits

A

have more than two distinct forms
(ex. blood types in humans)

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22
Q

Mutations

A

a change in DNA patterns (the raw material of evolution)

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23
Q

Mutations occur at ____ rates for each species

A

definite
(ex. in humans each child is born with an average of 64 new mutations in the ~20,000 genes present)

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24
Q

Mutation types:

A

Neutral mutation
Lethal mutation
Beneficial mutation

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25
Q

Neutral mutation:

A

has no effect on survival or reproduction

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26
Q

lethal mutation:

A

results in death

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27
Q

beneficial mutation:

A

bestows a slight advantage toward survival or reproduction

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28
Q

Sources of Mutations

A

random genetic changes
crossing over at meiosis I
independent assortment as meiosis I
fertilization

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29
Q

random genetic changes

A

creates new alleles in sperm or egg that is transmitted to the next generation

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30
Q

crossing over at meiosis I

A

mixes up maternal and paternal alleles on homologous chromosomes for forthcoming gametes

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31
Q

independent assortment at meiosis I

A

randomly distributes homologous chromosomes into gametes

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32
Q

fertilization

A

combines alleles from two different individuals creating organisms with genes unlike either parent

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33
Q

gene pool

A

the sum of ALL of the genes in a population

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34
Q

allele frequency

A

the rate at which a specific allele appears within a population

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35
Q

microevolution

A

change in allele frequency in the gene pool of a population or species
(always occurring in natural populations due to mutations/natural selection)

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36
Q

macroevolution

A

large scale evolutionary pattern above the species level

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37
Q

The Galapagos Finches

A

studied by Darwin and also present day as a demonstration of Evolution

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38
Q

Divergent Evolution

A

changes in body form (morphological divergence) from a common ancestor
(ex. homologous structures)

39
Q

homologous structures

A

structures in organisms that share the same basic form but appear in separate lineages because they evolves from a common ancestor
(ex. limbs in human, dog, bird, or whale)

40
Q

vestigial structures

A

structures that exist in organisms but have no apparent function at all
(ex. appendix, remnants of pelvis in snakes, wings that don’t fly, eyes that don’t see)

41
Q

body parts that appear similiar in different species are __ ____ homologous

A

Not Always

42
Q

convergent evolution

A

when similar traits evolve independently in species that do not share any recent common ancestry

43
Q

analogous structures

A

look alike but evolved independently
(ex. wing of bird, bat, and butterfly)

44
Q

transitional forms

A

an intermediate form of an organism linking two other organisms together

45
Q

Patterns of Natural Selection:

A

Directional selection
Stabilizing selection
Disruptive selection

46
Q

Directional selection

A

an extreme trait is more favorable

47
Q

stabilizing selection

A

an intermediate trait is more favorable

48
Q

disruptive selection

A

extremely different traits are more adaptive

49
Q

a selective pressure that can shape form and behavior

A

competition for mates

50
Q

sexual dimorphism

A

traits that differ between males and females (occurs in plants and animals)
due to sexual selection

51
Q

sexual selection

A

individuals with features (courtship displays) that better attract mates out-reproduce others
(females choose the mate/mates or males compete for access to females)

52
Q

balanced polymorphism and the heterozygote

A

two or more alleles continue circulating at a relatively high frequency in a population)
can arise in environments that favor heterozygous individuals
(ex. individuals that are heterozygous for sickle-cell anemia are resistant to malaria but don’t suffer from sickle-cell anemia)

53
Q

genetic variance

A

the diversity of alleles and genotypes within a population (maintained with sexual reproduction- asexual production leads to clones)

54
Q

Non-Selective Evolution

A

Evolution by Chance

55
Q

genetic drift

A

random change in an allele’s frequency over time by chance alone (right place at the right time or wrong place at the wrong time)

56
Q

bottleneck

A

results when a large portion of the genome suddenly gets wipe out- drastic reduction in population size can reduce genetic diversity

57
Q

founder effect

A

a small group establishes a new population and the genetic structure changes to match the new populations founders
(if founding group does not have high alleles variation neither will the new population)

58
Q

fixed allele

A

condition when all individuals of a population are homozygous for an allele (common among small population- will not change unless a mutation occurs or individual with another allele enters the population)

59
Q

gene flow

A

movement of alleles between populations
can result in change or stabilization of allele frequencies

60
Q

selective and non-selective evolution can lead to ____

A

speciation

61
Q

Speciation

A

an evolutionary process in which new species form
(occurs when populations crossbreed, increases the number of genetic differences)
**populations that have already diverged may come together and interbreed again

62
Q

How do Species Become Seperated:

A

Allopatric Speciation
Parapatric Speciation
Sympatric Speciation

63
Q

Allopatric speciation

A

arises from physical separation between populations
(reproduction isolation, geographic isolation)

64
Q

reproduction isolation

A

biological or physical barriers to gene flow
(influenced by how an organism reproduces-can prevent interbreeding even if populations meet again)

65
Q

geographic isolation

A

physical geographical barriers to gene flow
(influenced by how species travels)

66
Q

prezygotic barriers

A

obstacle to mating or to fertilization of mating occurs
(geographic isolation, ecological isolation, temporal isolation, behavioral isolation, mechanical isolation, genetic isolation)

67
Q

postzygotic isolating mechanisms

A

act after fertilization to prevent successful reproduction

68
Q

hybrid invisibility

A

the fertilized egg may fail to develop properly
fewer young may be produced and may have a low viability (survivability)

69
Q

hybrid sterility

A

hybrid of two species may be viable but sterile
(ex. mule)

70
Q

hybrid breakdown

A

first generation may be fertile but subsequent generations are infertile or non-viable

71
Q

sympatric speciation

A

populations inhabiting same region speciate in the absence of a physical barrier between them
(may occur when the chromosome number multiples, organisms choose different environments)

72
Q

parapatric speciation

A

creates a hybrid that is often sterile

73
Q

hybrid

A

a cross between 2 different species that are similar (different species may have different genes active during development so may not be possible to develop viable offspring)
ex. horse and donkey, african eagles and bald eagle, lion and tiger

74
Q

adaptive radiation

A

organisms that do not go extinct may undergo adaptive radiation- one lineage rapidly diverges into several new species, usually a result of a changing environment

75
Q

key innovation

A

new trait that allows one organism to exploit a habitat more efficiently or in a new way
(ex. hawaiian honeycreepers)

76
Q

coevolution

A

two species evolve jointly because of a close ecological connection
(ex. Yucca plant and Sphnx Moth)
co-evolution= symbiosis/mutualism

77
Q

4 Basic Misconceptions of Evolution

A
  1. Evolution was mischaracterized as theory when it was actually a hypothesis
  2. Individuals evolve
  3. Evolution explains the origin of life
  4. Organisms evolve with purpose
78
Q

Hardy-Weinberg Equilibrium

A

states that a population’s allele and genotype frequencies will remain constant in the absence of evolutionary mechanisms

79
Q

genetic equilibrium can only occur under these ideal conditions:

A

no mutation
no gene flow
large population size
random mating
no natural selection

80
Q

Which of the following defines an adaptation?
a) the results of differences in survival and reproductive rates
b) genetic variation within species
c) an inherited trait that helps the survival and/or reproduction of an organism
d) change occurring in a generation over time

A

c) an inherited trait that helps the survival and/or reproduction of an organism

81
Q

The basis of variation of characteristics within a species is due to:
a) mutations of differing types
b) genetics
c) homologous structures
d) both a and c are correct

A

d) both a and b are correct

82
Q

Which of the following evolve
a) mutations
b) populations
c) individuals
d) none of the above

A

b) populations

83
Q

Evolution can only occur if there are
a) mutations
b)variation in nature
c) variation in genes
d) all of the above are correct

A

d) all of the above are correct

84
Q

A change in the allele frequency in the gene pool of a population or species is called
a) allelle frequency
b) macroevolution
c) genome
d) microevolution

A

d) microevolution

85
Q

Homologous structures are proof of
a) evolution from a common ancestor
b) convergent evolution
c) divergent evolution
d) both a and c are correct

A

d) both a and c are correct

86
Q

When intermediate forms of a trait are selected against and 2 extremes of a trait are selected for this results in
a) directional selection
b) stabilizing selection
c) disruptive selection
d) transitional forms

A

c) disruptive selection

87
Q

When organisms have phenotypic traits that differ between sexes this is called
a) sexual reproduction
b) sexual dimorphism
c) sexual isolation
d) sexual attraction

A

b) sexual dimorphism

88
Q

When environmental pressures favor a heterozygote genetic makeup because the resultant trait makes an organism more successful in the environment it is called
a) incomplete dominance
b) genetic variance
c) dimorphism
d) balanced polymorphism

A

d) balanced polymorphism

89
Q

When a large portion of the genome suddenly becomes wiped out it is called the
a) founder effect
b) bottleneck effect
c) gene flow
d) fixed allele

A

b) bottleneck effect

90
Q

Which of the following describe evolutionary processes in which new species form
a) selective
b) non-selective
c) called speciation
d) all of the above are correct

A

d) all of the above are correct

91
Q

Speciation that results from physical separation between populations within a species is called
a) allopatric speciation
b) sympatric speciation
c) parapatric speciation
d) speciation

A

a) allopatric speciation

92
Q

Which of the following are examples of prezygotic reproductive isolation
a) birds using a different song to attract mates
b) sexual organisms not having a “perfect fit” for reproduction
c) organisms that rely on one another for fertilization are not active at the same time of day because of seasonal changes
d) all of the above are correct

A

d) all of the above are correct

93
Q

Which of the following are reasons for the morphological change in elephants from being tusked to not being tusked?
a) because humans are killing tusked elephants for ivory
b) because tusks are no longer needed in the prevailing environmental conditions
c) because elephants without tusks are surviving better compared to elephants with tusks
d) both a and c are correct

A

d) both a and c are correct

94
Q

Hardy-Weinberg Equilibrium states that genotype frequencies will remain constant in the absence of
a) mutations
b) gene flow
c) natural selection
d) all of the above must be present for equilibrium to occur

A

d) all of the above must be present for equilibrium to occur

BIO 102-General Biology 2 EC (4 decks)

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