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Bio 190 > Ch 19 > Flashcards

Ch 19 Flashcards

1
Q

_____ refers to changes in heritable characteristics of a population over time.

A

Evolution

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2
Q

empirical

A

In the 1600s, scholars using ______ thought rather than religion or philosophy began to rely on observation to look for the basic rationale behind a process

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3
Q

Who were the first scholars to suggest that the Earth is well over 6,000 years old?

A

Lyell and Hutton

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4
Q

Malthus, an economist, made a valuable contribution to the growth of biological thought by suggesting

A

that not all members of a population will survive and reproduce.

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5
Q

What group of islands was home to organisms such as finches with distinctive traits observed by Darwin on the voyage of the Beagle?

A

Galapagos Islands

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6
Q

Heritable change in traits of a population from one generation to the next is called

A

evolution

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7
Q

While the Galápagos finches have descended from a common ancestor, the striking differences in their beaks evolved due to

A

increased ability to survive and reproduce based on changes over time in beak size and shape.

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8
Q

What type of thought relies on observation to form an idea or hypothesis about a natural phenomenon?

A

Empirical

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9
Q

Darwin’s theory of evolution is also known as

A

descent with modification through variation and natural selection.

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10
Q

True or false: According to Hutton and Lyell, proponents of uniformitarianism, the Earth was only 6,000 years old.

A

False

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11
Q

According to Darwin’s ideas, two factors interact to bring about evolutionary change: genetic change and

A

natural selection

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12
Q

Why was Malthus’ work instrumental to Darwin’s formation of the theory of evolution by natural selection?

A

He suggested that limited resources affect population growth.

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13
Q

Some of the offspring produced by each generation may not survive and reproduce because

A

resources are often limited.

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14
Q

During the voyage of the Beagle, Darwin was particularly struck by the distinctive traits of

A

island species.

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15
Q

Consider a population of seed-eating finch species that colonizes an island. Due to genetic variation, some of the birds in the population have larger beaks than others. If the island contains only tree species that produce much larger seeds than those found in the previous habitat of the bird, what changes are likely to occur in this population over time?

A
  • The average beak size of the finch population will increase with time.
  • Individuals with smaller beaks will not be able to crush the large seeds and will have a smaller chance of survival and reproduction.
  • Individuals with larger beaks that can eat bigger seeds will reproduce more frequently.
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16
Q

It is now known that Darwin’s Galápagos finches

A

evolved from a single species similar to a finch commonly found along the Pacific Coast of South America.

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17
Q

Darwin’s observation that there were Patagonian hares but no rabbits in South America would be considered ______ evidence of evolution.

A

biogeographical

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18
Q

Darwin expressed his concept of evolution as “the theory of ___ with ____ through the variation and natural selection.”

A

descent & modification

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19
Q

A(n) form displays features of both an ancestral form and the form of its more modern descendants.

A

transitional

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20
Q

Darwin believed that evolution occurs from generation to generation due to which two interacting factors?

A

Natural selection

Genetic variation

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21
Q

Select the features present in fossils of T. roseae, also known as fishapod.

A

Some of its fins had a primitive wrist with five finger-like bones.
It had a broad skull.
Its eyes were on the top of the head.

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22
Q

Not all of the offspring produced by an organism will survive and reproduce. Why?

A
  • Organisms produce more offspring than the environment can support.
  • Environmental resources are often limited.
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23
Q

the study of the geographic distribution of modern and extinct species.

A

Biogeography

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24
Q

Shell size and shape in a species of snail varies, with two shapes being most common: thin walled with a pointed spire, and thick walled with a low, rounded spire. If a species of crab that eats snails by crushing their shells moves into an area with roughly equal numbers of snails with the two shell shapes, what do you predict will happen over the course of the next 50 generations of snails?

A

Thick-shelled snails will survive better and leave more offspring, and will become more numerous in the population.

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25
Q

Most endemic island species have close relatives

A

on the nearby islands or mainland.

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26
Q

All of the following can provide evidence of biological evolution EXCEPT:

A

Reproduction

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27
Q

What features does a transitional form display?

A

Both features of its ancestral forms and its descendants.

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28
Q

evolution occurs when two species from different lineages independently evolve similar characteristics because they occupy similar environments.

A

Convergent

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29
Q

Procedures in which matings or crosses are designed to modify traits in domesticated species are referred to as

A

selective breeding.

30
Q

The features of Tiktaalik, a fossil that is a transitional form between fishes and tetrapods, might have allowed what actions?

A
  • Ability to move out of the water for short periods
  • Ability to support body on river bottoms
  • Ability to lift the head above water
31
Q

In _____________ selection, humans choose the parents of the next generation, while in ______________ selection, organisms that survive and reproduce are those that pass their genes on.

A

artificial / natural

32
Q

Biogeography is the study of

A

the geographic distribution of modern and extinct species.

33
Q

True or false: Selective breeding has only recently become possible because of advances in our knowledge of genetic

A

False

34
Q

has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that

A

island forms and mainland forms descended from common ancestors.

35
Q

Evolutionary theory can explain structures, which are functional anatomical structures in related organisms that are similar based on their origin from a common ancestor.

A

homologous

36
Q

Consider two species from different lineages that have independently evolved comparable traits because they occupy similar environments. This similarity is the result of:

A

Convergent evolution

37
Q

What molecular evidence indicates that all living things evolved from a common ancestor or a very closely related group of ancestors?

A

The same gene can be found in diverse types of organisms.

38
Q

In selective breeding programs, artificial selection modifies domesticated species to produce traits that are

A

desirable from a human perspective.

39
Q

What is a gene pool?

A

All of the alleles for every gene in a population

40
Q

The primary difference between natural and artificial selection is

A

how the parents are chosen: by humans or by increased survival and reproductive success.

41
Q

A set of individuals of the same species inhabiting the same environment at the same time make up a

A

population

42
Q

What have humans conducted for centuries to produce domesticated species with desirable traits?

A

Selective breeding

43
Q

Polymorphic genes are most commonly caused by:

A

changes in a single nucleotide (SNPs)

44
Q

The wings of a bat and the arms of a human are examples of

A

homologous structures.

45
Q

The frequency at which homozygotes and heterozygotes occur within a population can be described by:

A

genotype frequencies

46
Q

What do molecular homologies tell us about the evolution of living things?

A

Living things have evolved from an interrelated group of ancestors.

47
Q

The MN blood group in humans is determined by two alleles of a single gene. In a population containing 90 individuals with genotype MM and blood group M, 80 individuals with genotype MN and blood group MN, and 30 individuals with genotype NN and blood group N, what is the frequency of the genotype MN?

A

40%

48
Q

In four-o’clock plants, flowers with the genotype CRCR are red, flowers with the genotype CRCW are pink, and flowers with the genotype CWCW are white. A population of four-o’clocks consists of 30 plants with red flowers, 10 plants with pink flowers, and 60 plants with white flowers. What is the frequency of the CR allele in this population?
Multiple choice question.

A

.35

49
Q

SNP stands for ______ and is the smallest type of genetic variation that can lead to polymorphic gen

A

single

50
Q

According to the Hardy-Weinberg equation for a gene with two alleles, the sum of the frequency of one allele (p) and the other allele (q) equals

A

1.0

51
Q

In radishes, genotype RR is red, genotype Rr is purple, and genotype rr is white. In a population of radishes consisting of 100 red radishes, 100 purple radishes, and 300 white radishes, what is the frequency of the genotype rr?

A

.60

52
Q

A particular gene segregates two alleles, and the dominant allele has a frequency of 0.9. What is the frequency of the recessive allele?

A

.1

53
Q

Consider a population of 100 four o’clock flowers, where 55 flowers are red and have the genotype CRCR, 20 flowers are pink and have the genotype CRCW, and 25 flowers are white with the genotype CWCW. The frequency of the CR allele in this population is

A

.65

54
Q

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.4. What is the percentage of the population that is homozygous for this allele?

A

16%

55
Q

In a diploid species, how many copies of a given allele are present in an individual who is heterozygous for the gene?

A

1

56
Q

For a population to be in Hardy-Weinberg equilibrium, there must be:

A

no new mutations, and no survival or reproductive advantage for any of the genotypes

57
Q

For a gene with two alleles, if the frequency of one allele in a population that is not evolving is symbolized p and the frequency of the other allele in the population is symbolized q, then

A

p + q = 1.

58
Q

If a population is not in Hardy-Weinberg equilibrium, it means that

A

evolution is occurring.

59
Q

*Gene duplication is

A

Formation of a gene family due to replication of a gene followed by random mutation in each copy

60
Q

Random mutation

A

Generation of new alleles of pre-existing genes

61
Q

Horizontal gene transfer

A

Introduction of genes from one species into another species

62
Q

For a gene with two alleles, S and s, if the frequency of the one allele (S) is 0.25, then the frequency of the other allele(s) is .

A

.75 or 75%

63
Q

Select the evolutionary mechanisms that alter the frequencies of existing alleles in a population.

A

Migration
Genetic drift
Natural selection

64
Q

A student proposes that left-handedness is a recessive trait. A survey of a class of 36 students finds that 27 (0.75) are right-handed and 9 (0.25) are left-handed. If this population is in Hardy-Weinberg equilibrium, what are the genotypic and allele frequencies?

A

0.25 homozygous dominant, 0.50 heterozygous, and 0.25 homozygous recessive, and a 0.5 allele frequency for each allele

65
Q

Which of the following conditions are assumed by the Hardy-Weinberg equation?

A

Mating is random.
No new mutations occur.
No migration is occurring.

66
Q

What conclusion can be drawn from the observation that a population is not in Hardy-Weinberg equilibrium?

A

Evolutionary forces are affecting the population.

67
Q

Natural selection

A

Changes in allele frequencies due to heritable variation that affects fitness

68
Q

Genetic drift

A

Changes in allele frequencies due to random chance

69
Q

Migration

A

Introduction of alleles from another population

70
Q

Nonrandom mating

A

Selection of mates based on phenotypes or genetic lineage

71
Q

Natural selection, genetic drift, and migration can all result in changes in

A

both allele frequencies and genotype frequencies.

Bio 190 (21 decks)

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