Chapter 10: Natural Selection. Evolution Flashcards
(161 cards)
1
Q
What is phenotypic variation?
A
Observable differences in traits among individuals in a population.
2
Q
What causes genetic variation?
A
Mutation
3
Q
What is the significance of genetic variation in evolution?
A
It provides raw material for natural selection.
4
Q
How are new alleles produced?
A
By mutation.
5
Q
What process reshuffles existing alleles?
A
Meiosis.
6
Q
What is a somatic mutation?
A
A mutation in body cells
7
Q
What happens if a gamete mutation forms a zygote?
A
The mutation is passed to offspring.
8
Q
What is natural selection?
A
A process where alleles conferring survival advantages increase in frequency.
9
Q
What is a selection pressure?
A
Environmental factors that influence allele frequencies.
10
Q
What is fitness in biological terms?
A
The ability of an organism to survive and reproduce.
11
Q
What are biotic factors in natural selection?
A
Predators
12
Q
What are abiotic factors in natural selection?
A
Water supply and soil nutrients.
13
Q
What is directional selection?
A
A type of natural selection favoring one extreme phenotype.
14
Q
What is stabilizing selection?
A
A type of natural selection that preserves average phenotypes.
15
Q
What is disruptive selection?
A
A type of natural selection that favors extreme phenotypes over intermediate ones.
16
Q
What is the key to natural selection?
A
Variation within a species.
17
Q
What increases offspring survival rates?
A
Adaptations suited to the environment.
18
Q
What happens to less adapted individuals?
A
They produce fewer offspring or die.
19
Q
What is the outcome of many generations of selection?
A
Populations become better adapted to their environments.
20
Q
How does antibiotic resistance occur?
A
Selection pressures favor resistant bacterial alleles.
21
Q
What are plasmids?
A
Small DNA loops that transfer genetic information in bacteria.
22
Q
What causes industrial melanism?
A
Predation and environmental changes favor darker phenotypes.
23
Q
Why is the sickle cell allele common in malaria regions?
A
Carriers are resistant to malaria.
24
Q
What is the role of overproduction in evolution?
A
It leads to competition and selection of better-adapted individuals.
25
What is speciation?
The formation of new species.
26
What is allopatric speciation?
Speciation due to geographic isolation.
27
What is sympatric speciation?
Speciation without geographic isolation.
28
What causes reproductive isolation?
Prezygotic and postzygotic barriers.
29
What are prezygotic isolation mechanisms?
Barriers preventing fertilization (e.g.
30
What are postzygotic isolation mechanisms?
Barriers affecting zygote viability or fertility.
31
What is polyploidy?
Having more than two sets of chromosomes
32
What is the Hardy-Weinberg principle?
A formula to calculate genotype frequencies in populations.
33
What is artificial selection?
Human-driven selection for specific traits.
34
Why is inbreeding disadvantageous?
It reduces genetic diversity
35
What is outbreeding?
Breeding less related organisms for healthier offspring.
36
What is genetic drift?
Random changes in allele frequencies in small populations.
37
What is a species?
Organisms that can interbreed to produce fertile offspring.
38
What are Darwin’s finches an example of?
Adaptive radiation due to allopatric speciation.
39
How do antibiotics exert selection pressure?
By killing susceptible bacteria
40
What is industrial melanism in moths?
Dark moths had a survival advantage in polluted areas.
41
How do diploid and tetraploid plants differ?
Tetraploids have four chromosome sets and cannot interbreed with diploids.
42
What does "variation within a population" mean?
Differences in traits among individuals of the same species.
43
Why is heritable variation critical for natural selection?
Only traits passed to offspring can influence evolution.
44
What is the role of predation in shaping populations?
It eliminates individuals less suited to avoid predators.
45
What happens if environmental conditions remain stable for long periods?
Stabilizing selection maintains the status quo.
46
What happens if environmental conditions change rapidly?
Directional or disruptive selection may occur.
47
What is the consequence of extreme environmental pressures?
Extinction or rapid evolutionary changes.
48
Why do most mutations not affect evolution?
Many are neutral or occur in somatic cells and are not passed on.
49
What is the impact of genetic bottlenecks on natural selection?
They reduce genetic diversity
50
What is an example of genetic variation providing survival benefits?
Antibiotic resistance in bacteria.
51
How does disease act as a selection pressure?
It favors individuals with resistance genes.
52
What is selective advantage?
A trait that increases an organism's fitness.
53
What is selective disadvantage?
A trait that reduces an organism's fitness.
54
How does artificial selection differ from natural selection?
Humans intentionally choose which traits are passed on.
55
What is an example of artificial selection?
Breeding dogs for specific traits.
56
What is the difference between natural and sexual selection?
Natural selection focuses on survival
57
What is sexual selection?
The process where certain traits increase mating success.
58
What is an example of sexual selection?
Peacock feathers attracting mates.
59
How does camouflage benefit prey in natural selection?
It reduces predation by making them less visible.
60
How does mimicry aid survival?
It helps an organism resemble another for protection or deception.
61
What is coevolution?
When two species evolve in response to each other (e.g.
62
What is microevolution?
Small changes in allele frequencies within a population.
63
What is macroevolution?
Large-scale evolutionary changes
64
What is an example of macroevolution?
The evolution of mammals from reptiles.
65
How does the fossil record support evolution?
It shows gradual changes in species over time.
66
What is a transitional fossil?
A fossil showing features of both ancestral and descendant species.
67
What is phenotypic variation?
Observable differences in traits among individuals in a population.
68
What causes genetic variation?
Mutation
69
What is the significance of genetic variation in evolution?
It provides raw material for natural selection.
70
How are new alleles produced?
By mutation.
71
What process reshuffles existing alleles?
Meiosis.
72
What is a somatic mutation?
A mutation in body cells
73
What happens if a gamete mutation forms a zygote?
The mutation is passed to offspring.
74
What is natural selection?
A process where alleles conferring survival advantages increase in frequency.
75
What is a selection pressure?
Environmental factors that influence allele frequencies.
76
What is fitness in biological terms?
The ability of an organism to survive and reproduce.
77
What are biotic factors in natural selection?
Predators
78
What are abiotic factors in natural selection?
Water supply and soil nutrients.
79
What is directional selection?
A type of natural selection favoring one extreme phenotype.
80
What is stabilizing selection?
A type of natural selection that preserves average phenotypes.
81
What is disruptive selection?
A type of natural selection that favors extreme phenotypes over intermediate ones.
82
What is the key to natural selection?
Variation within a species.
83
What increases offspring survival rates?
Adaptations suited to the environment.
84
What happens to less adapted individuals?
They produce fewer offspring or die.
85
What is the outcome of many generations of selection?
Populations become better adapted to their environments.
86
How does antibiotic resistance occur?
Selection pressures favor resistant bacterial alleles.
87
What are plasmids?
Small DNA loops that transfer genetic information in bacteria.
88
What causes industrial melanism?
Predation and environmental changes favor darker phenotypes.
89
Why is the sickle cell allele common in malaria regions?
Carriers are resistant to malaria.
90
What is the role of overproduction in evolution?
It leads to competition and selection of better-adapted individuals.
91
What is speciation?
The formation of new species.
92
What is allopatric speciation?
Speciation due to geographic isolation.
93
What is sympatric speciation?
Speciation without geographic isolation.
94
What causes reproductive isolation?
Prezygotic and postzygotic barriers.
95
What are prezygotic isolation mechanisms?
Barriers preventing fertilization (e.g.
96
What are postzygotic isolation mechanisms?
Barriers affecting zygote viability or fertility.
97
What is polyploidy?
Having more than two sets of chromosomes
98
What is the Hardy-Weinberg principle?
A formula to calculate genotype frequencies in populations.
99
What is artificial selection?
Human-driven selection for specific traits.
100
Why is inbreeding disadvantageous?
It reduces genetic diversity
101
What is outbreeding?
Breeding less related organisms for healthier offspring.
102
What is genetic drift?
Random changes in allele frequencies in small populations.
103
What is a species?
Organisms that can interbreed to produce fertile offspring.
104
What are Darwin’s finches an example of?
Adaptive radiation due to allopatric speciation.
105
How do antibiotics exert selection pressure?
By killing susceptible bacteria
106
What is industrial melanism in moths?
Dark moths had a survival advantage in polluted areas.
107
How do diploid and tetraploid plants differ?
Tetraploids have four chromosome sets and cannot interbreed with diploids.
108
What does "variation within a population" mean?
Differences in traits among individuals of the same species.
109
Why is heritable variation critical for natural selection?
Only traits passed to offspring can influence evolution.
110
What is the role of predation in shaping populations?
It eliminates individuals less suited to avoid predators.
111
What happens if environmental conditions remain stable for long periods?
Stabilizing selection maintains the status quo.
112
What happens if environmental conditions change rapidly?
Directional or disruptive selection may occur.
113
What is the consequence of extreme environmental pressures?
Extinction or rapid evolutionary changes.
114
Why do most mutations not affect evolution?
Many are neutral or occur in somatic cells and are not passed on.
115
What is the impact of genetic bottlenecks on natural selection?
They reduce genetic diversity
116
What is an example of genetic variation providing survival benefits?
Antibiotic resistance in bacteria.
117
How does disease act as a selection pressure?
It favors individuals with resistance genes.
118
What is selective advantage?
A trait that increases an organism's fitness.
119
What is selective disadvantage?
A trait that reduces an organism's fitness.
120
How does artificial selection differ from natural selection?
Humans intentionally choose which traits are passed on.
121
What is an example of artificial selection?
Breeding dogs for specific traits.
122
What is the difference between natural and sexual selection?
Natural selection focuses on survival
123
What is sexual selection?
The process where certain traits increase mating success.
124
What is an example of sexual selection?
Peacock feathers attracting mates.
125
How does camouflage benefit prey in natural selection?
It reduces predation by making them less visible.
126
How does mimicry aid survival?
It helps an organism resemble another for protection or deception.
127
What is coevolution?
When two species evolve in response to each other (e.g.
128
What is microevolution?
Small changes in allele frequencies within a population.
129
What is macroevolution?
Large-scale evolutionary changes
130
What is an example of macroevolution?
The evolution of mammals from reptiles.
131
How does the fossil record support evolution?
It shows gradual changes in species over time.
132
What is a transitional fossil?
A fossil showing features of both ancestral and descendant species.
133
What is convergent evolution?
When unrelated species evolve similar traits due to similar environments.
134
What is divergent evolution?
When species evolve in different directions from a common ancestor.
135
What is an example of convergent evolution?
Wings in bats and birds.
136
What is adaptive radiation?
The evolution of many species from a single ancestor into diverse forms.
137
What triggers adaptive radiation?
New habitats or niches becoming available.
138
What is punctuated equilibrium?
Evolution characterized by long periods of stasis interrupted by rapid changes.
139
What is gradualism in evolution?
The theory that evolution occurs slowly over time.
140
What is the gene pool?
The total collection of alleles in a population.
141
What is genetic drift?
Random changes in allele frequencies
142
What are the two main types of genetic drift?
Bottleneck effect and founder effect.
143
What is the bottleneck effect?
A sharp reduction in population size
144
What is the founder effect?
When a new population is established by a small number of individuals.
145
What is an example of the founder effect?
High prevalence of genetic disorders in isolated populations.
146
What is the role of migration in evolution?
It introduces new alleles into a population
147
What is gene flow?
The transfer of alleles between populations.
148
What is an example of gene flow?
Pollen transfer between plant populations.
149
How does natural selection differ from genetic drift?
Natural selection is non-random
150
What is a genetic polymorphism?
The occurrence of two or more alleles at a locus in a population.
151
What is balanced polymorphism?
When two alleles are maintained in a population due to selective advantages.
152
What is an example of balanced polymorphism?
Sickle cell trait in malaria-prone regions.
153
What is fitness in evolutionary terms?
The ability to survive and reproduce in a given environment.
154
What is the Red Queen hypothesis?
Species must continuously evolve to keep up with coevolving species.
155
How does the environment shape evolution?
It creates selection pressures that favor certain traits.
156
Why is evolution considered a continuous process?
Environments and selection pressures are always changing.
157
What is exaptation?
A trait that evolves for one function but is later adapted for another.
158
What is a clade in phylogenetics?
A group of organisms that includes an ancestor and all its descendants.
159
What is a phylogenetic tree?
A diagram showing evolutionary relationships among species.
160
What is the significance of molecular clocks?
They estimate the timing of evolutionary events based on mutation rates.
161
What is horizontal gene transfer?
The transfer of genetic material between organisms without reproduction.
