Genetics and Evolution Flashcards
(274 cards)
1
Q
Who developed the concepts of genetics through his work with pea plants?
A
Gregor Mendel
2
Q
Where is genetic information stored in a cell?
A
In chromosomes, which is found in the nucleus
3
Q
locus
A
The location of a specific gene on a chromosome
4
Q
genes
A
Sections of DNA that code for traits
5
Q
What are alternative forms of a gene called?
A
Alleles
6
Q
What term describes the complete set of genetic material in an organism?
A
Genome
7
Q
genotype
A
The collection of genes in an organism that codes for traits
8
Q
homologous chromosomes
A
those with the same pair of chromosomes
9
Q
ploidy
A
The number of complete chromosome sets per cell
10
Q
What type of cells have only one set of chromosomes?
A
Haploid cells
11
Q
What type of cells have two sets of chromosomes?
A
Diploid cells
12
Q
What results in homozygous genotypes?
A
Homologous chromosomes carrying the same alleles of a gene
13
Q
What results in heterozygous genotypes?
A
Homologous chromosomes carrying different alleles of a gene
14
Q
hemizygosity
A
one allele is present in a diploid organism
15
Q
phenotype
A
An organism’s observable (physical) characteristics determined by genotype and environment.
16
Q
genetic polymorphism
A
The presence of multiple alleles of one or more genes causing variation in a trait.
17
Q
How are traits categorized?
A
as qualitative or quantitative
18
Q
Mendelian traits
A
Traits passed down on one gene w/ dominant and recessive alleles
19
Q
complete dominance
A
A pattern where the dominant allele fully masks a recessive allele.
20
Q
codominance
A
A pattern where two different alleles are fully expressed in heterozygotes.
21
Q
incomplete dominance
A
A pattern where the phenotype of heterozygotes is a blend of the two alleles.
22
Q
What does penetrance measure?
A
The percentage of individuals with a given genotype expressing the phenotype.
23
Q
expressivity
A
The degree to which individuals with a given genotype express the associated phenotype.
24
Q
quantitative traits
A
have a continuous distribution and can be measured
25
qualitative traits
grouped into discrete categories
26
law of independent assortment
different genes and their alleles are inherited independently of one another
27
recombination
the process by which genetic material is physically mixed during meiosis, resulting in offspring with combinations of traits that differ from those in either parent.
28
Fill in the blank: The exchange of genetic material between homologous chromosomes during meiosis is known as __________.
crossing over
29
What are homologous chromosomes?
pairs of chromosomes that have the same structure and gene sequence but may contain different alleles.
30
During which phase of meiosis does crossing over occur?
Prophase I
31
Multiple Choice: What is the main benefit of recombination?
Increased genetic diversity
32
What structures are formed during crossing over?
Chiasmata
33
True or False: Recombination can only occur in sexually reproducing organisms.
True
34
What is the result of crossing over between two chromosomes?
New combinations of alleles
35
Multiple Choice: Which of the following is NOT a consequence of recombination?
Decreased genetic variation
36
What is the significance of genetic recombination in evolution?
It contributes to genetic variation, which is essential for natural selection.
37
True or False: Recombination can lead to genetic disorders.
True
38
recombinant chromosome
A chromosome that has undergone recombination and contains a mix of alleles from both parents.
39
Fill in the blank: Recombination occurs more frequently in __________ chromosomes.
homologous
40
What is the role of enzymes in the crossing over process?
Enzymes facilitate the breaking and rejoining of DNA strands during crossing over.
41
Multiple Choice: Which of the following processes increases genetic diversity in a population?
Recombination
42
What is the term for the non-sister chromatids that participate in crossing over?
Homologous chromatids
43
True or False: Crossing over can occur multiple times during meiosis.
True
44
What is the primary function of recombination in meiosis?
To create genetic variation in gametes
45
Fill in the blank: The physical exchange of chromosome segments during crossing over is crucial for __________.
genetic diversity
46
What is a tetrad in the context of meiosis?
a group of four chromatids formed during prophase I when homologous chromosomes pair up.
47
Multiple Choice: Which of the following statements is true about crossing over?
It occurs between homologous chromosomes.
48
What is the significance of chiasmata in recombination?
Chiasmata are the physical points where crossing over occurs, allowing for the exchange of genetic material.
49
True or False: Recombination occurs during both meiosis and mitosis.
False
50
What is the main difference between recombination and independent assortment?
Recombination involves the exchange of genetic material between chromosomes, while independent assortment refers to the random distribution of chromosomes to gametes.
51
Fill in the blank: The exchange of genetic material during crossing over results in __________ offspring.
genetically unique
52
Punnett Square
A diagram used to predict the genetic outcomes of a monohybrid cross.
53
True or False: A monohybrid cross involves one trait.
True
54
Fill in the blank: In a Punnett Square, the alleles of one parent are placed on the ____ and the alleles of the other parent are placed on the ____.
top; side
55
What do uppercase letters represent in a Punnett Square?
Dominant alleles.
56
What do lowercase letters represent in a Punnett Square?
Recessive alleles.
57
In a monohybrid cross between two heterozygous parents (Tt x Tt), what is the expected phenotypic ratio?
3:1
58
What is the genotypic ratio from a monohybrid cross Tt x Tt?
1:2:1
59
True or False: The offspring of a monohybrid cross can only show the dominant trait.
False
60
In genetics, what does the term 'allele' refer to?
Different forms of a gene.
61
If a parent has the genotype AA, what alleles can they pass on to their offspring?
Only A alleles.
62
What are the possible genotypes of offspring from a cross between AA and Aa?
AA and Aa.
63
Fill in the blank: The phenotype is the ____ expression of a genotype.
physical
64
True or False: Monohybrid crosses can be used to study multiple traits simultaneously.
False
65
What is the F1 generation in a genetic cross?
The first generation of offspring from the parental generation.
66
What is the expected ratio of homozygous to heterozygous offspring from a cross of TT and Tt?
1:1
67
In a cross between a homozygous dominant and a homozygous recessive organism, what will the offspring's genotype be?
All heterozygous.
68
What does the term 'phenotypic ratio' refer to?
The ratio of different phenotypes in the offspring.
69
What is the expected phenotypic ratio for a cross between two homozygous parents (TT x tt)?
All offspring will display the dominant phenotype.
70
True or False: A Punnett Square can only be used for predicting outcomes in plants.
False
71
What kind of traits can be analyzed using a Punnett Square?
Any traits governed by Mendelian inheritance.
72
How many squares are in a standard 2x2 Punnett Square?
Four squares.
73
In a monohybrid cross, what does the 'P' generation represent?
The parental generation.
74
What is the significance of the 3:1 ratio in a monohybrid cross?
It indicates the expected ratio of dominant to recessive phenotypes.
75
dihybrid cross
A genetic cross involving two traits, each controlled by different genes.
76
What is the expected phenotypic ratio in the F2 generation of a dihybrid cross?
The expected phenotypic ratio is 9:3:3:1.
77
True or False: A dihybrid cross can only involve traits that are linked.
False.
78
What do the letters in a dihybrid cross (e.g., AaBb) represent?
The alleles for two different traits, where 'A' and 'a' are one trait and 'B' and 'b' are another.
79
Fill in the blank: In a dihybrid cross, the genotype of the parents can be represented as _____ x _____.
AaBb x AaBb.
80
What is the purpose of a Punnett square in a dihybrid cross?
To predict the genotypic and phenotypic ratios of the offspring.
81
What are the four possible gametes produced by an individual with the genotype AaBb?
AB, Ab, aB, ab.
82
What is the term for alleles that are expressed in the phenotype when present?
Dominant alleles.
83
What is the term for alleles that are only expressed in the phenotype when two copies are present?
Recessive alleles.
84
In a dihybrid cross, how many total boxes are in the Punnett square for AaBb x AaBb?
16 boxes.
85
True or False: Dihybrid crosses can be used to study the inheritance of traits that are on the same chromosome.
True.
86
What is the phenotypic ratio for a dihybrid cross involving two traits that are completely linked?
1:1:1:1.
87
In a dihybrid cross with two heterozygous parents, what fraction of the offspring is expected to display both dominant traits?
9/16.
88
What type of inheritance pattern does a dihybrid cross typically illustrate?
Mendelian inheritance.
89
True or False: In a dihybrid cross, the traits being studied must be on different chromosomes.
False.
90
What is the genotype ratio expected from a dihybrid cross of AaBb x AaBb?
1 AABB : 2 AABb : 2 AaBB : 4 AaBb : 1 AAbb : 2 Aabb : 1 aaBB : 2 aaBb : 1 aabb.
91
Fill in the blank: When conducting a dihybrid cross, the first step is to determine the _____ of the parents.
genotypes.
92
What is a test cross, and how is it related to dihybrid crosses?
A test cross involves crossing an individual with a homozygous recessive to determine its genotype; it can be used in dihybrid crosses to confirm genotypes of the parents.
93
How many different phenotypes can be produced from a dihybrid cross of two heterozygous parents?
Four different phenotypes.
94
True or False: Dihybrid crosses can be used to study the inheritance of multiple traits at once.
True.
95
What is the main difference between a monohybrid cross and a dihybrid cross?
A monohybrid cross involves one trait, while a dihybrid cross involves two traits.
96
X-linked trait
A trait that is associated with a gene located on the X chromosome.
97
True or False: Males have two X chromosomes.
False
98
What is the probability that a son will inherit an X-linked recessive trait from his mother?
50%
99
Fill in the blank: X-linked traits are more commonly expressed in _____
males
100
Which of the following is an example of an X-linked recessive disorder? A) Cystic fibrosis B) Hemophilia C) Sickle cell anemia
B) Hemophilia
101
What is the typical inheritance pattern of X-linked dominant traits?
Affected males pass the trait to all daughters but no sons.
102
True or False: Females can be carriers of X-linked recessive traits.
True
103
What is the chance of a carrier mother passing an X-linked recessive trait to her daughter?
50%
104
Fill in the blank: X-linked traits are inherited through _____ chromosomes.
X
105
How many X chromosomes do females have?
Two
106
What can result from a mutation in an X-linked gene?
An X-linked disorder or trait.
107
True or False: X-linked traits can skip generations.
True
108
What is the expected phenotype of a female who is homozygous for an X-linked recessive trait?
Affected
109
Which parent determines the X-linked trait for a son?
Mother
110
What is the term for an individual who has one normal and one mutated X chromosome?
Carrier
111
Which of the following is NOT an X-linked trait? A) Color blindness B) Duchenne muscular dystrophy C) Tay-Sachs disease
C) Tay-Sachs disease
112
Fill in the blank: X-linked traits are typically expressed in males because they have only _____ X chromosome.
one
113
What is the inheritance pattern of X-linked traits in females?
Females can be homozygous or heterozygous for the trait.
114
True or False: All X-linked traits are recessive.
False
115
What is the likelihood of a daughter inheriting an X-linked recessive trait if her father is affected?
100%
116
Fill in the blank: The color blindness gene is located on the _____ chromosome.
X
117
What is the effect of a father who carries an X-linked recessive trait on his children?
He will pass the trait to all his daughters and none of his sons.
118
What is the significance of the X-inactivation process in females?
It equalizes the dosage of X-linked genes between males and females.
119
True or False: X-linked dominant traits are always expressed in females.
True
120
What is the role of a pedigree chart in studying X-linked traits?
It helps to track the inheritance patterns of traits through generations.
121
evolution
a change in the gene pool of a population over time
122
allele frequencies
measures how prevalent each allele is
123
Genetic drift
the random change of allele frequencies in a population over time
124
Mutation
a change in the DNA sequence of an organism
125
Natural selection
a process where organisms that are better suited to their environment tend to survive and reproduce more successfully than those that are not well-suited
126
Nonrandom mating
a mating system where some organisms are more or less likely to mate with organisms of a particular genotype than with organisms of other genotypes
127
Gene flow
the transfer of genetic material between populations of a species
128
what are the five evolutionary processes?
genetic drift, natural selection, mutation, gene flow, and nonrandom meeting
129
True or False: Natural selection is a random process.
False
130
What are the four main principles of natural selection?
Variation, inheritance, high rate of population growth, and differential survival and reproduction.
131
Which scientist is most associated with the theory of natural selection?
Charles Darwin
132
Multiple Choice: Which of the following is NOT a requirement for natural selection to occur? A) Variation B) Overproduction C) Genetic mutation D) Differential survival
C) Genetic mutation
133
What role does variation play in natural selection?
Variation provides the differences among individuals in a population that can be selected for or against.
134
True or False: Only the strongest individuals survive in natural selection.
False
135
Short Answer: How does inheritance affect natural selection?
Traits that confer an advantage must be heritable for natural selection to affect future generations.
136
Fill in the blank: Natural selection can lead to __________, which is the accumulation of advantageous traits over generations.
adaptation
137
Multiple Choice: What is the result of natural selection over time? A) Extinction B) Stabilization C) Evolution D) All of the above
D) All of the above
138
What is meant by 'differential survival' in the context of natural selection?
Differential survival refers to the idea that some individuals have a higher likelihood of surviving and reproducing based on their traits.
139
True or False: Natural selection can only act on physical traits.
False
140
Short Answer: Name one example of a trait that might be favored by natural selection.
Camouflage in prey species.
141
Fill in the blank: The concept of __________ explains how species evolve through the gradual accumulation of changes.
descent with modification
142
Multiple Choice: Which of the following describes a population's ability to adapt to its environment? A) Gene flow B) Genetic drift C) Fitness D) Mutation
C) Fitness
143
What is 'fitness' in the context of natural selection?
Fitness refers to an individual's ability to survive and reproduce in its environment.
144
True or False: Natural selection can occur without environmental changes.
True
145
Short Answer: How can natural selection lead to speciation?
Natural selection can lead to speciation by favoring different traits in populations that become isolated from one another.
146
Fill in the blank: The __________ hypothesis suggests that natural selection can lead to rapid bursts of evolution.
punctuated equilibrium
147
Multiple Choice: Which of the following is an example of natural selection? A) A farmer selecting crops B) A predator choosing prey C) A genetic mutation D) Both A and B
D) Both A and B
148
What is the significance of the Galápagos Islands in relation to natural selection?
The Galápagos Islands provided Charles Darwin with critical observations of species adaptation to different environments.
149
True or False: Natural selection can lead to the development of new species.
True
150
Short Answer: What is an example of human-induced natural selection?
Antibiotic resistance in bacteria.
151
Fill in the blank: __________ is the process by which unrelated species evolve similar traits due to similar environments.
Convergent evolution
152
Multiple Choice: Which of the following is a method of evidence for natural selection? A) Fossil records B) Comparative anatomy C) Molecular biology D) All of the above
D) All of the above
153
What are the three types of natural selection?
Disruptive, stabilizing, and directional selection
154
directional selection
occurs when individuals with one extreme phenotype have the highest fitness in the population, which results in a shift towards that extreme over time
155
stabilizing selection
favors intermediate phenotypes, which leads to a shift towards intermediate values in the population.
156
disruptive selection
occurs when intermediate phenotypes are selected against, which favors two extreme phenotypes because both are advantageous.
157
which form of natural selection is most commonly observed because extreme phenotypes are often disadvantageous?
stabilizing selection
158
True or false: disruptive selection has a decrease in the prevalence of intermediate phenotypes over generations.
true
159
What are the three key patterns of evolution?
Divergent, convergent, and parallel evolution
160
Divergent evolution
Occurs when closely related lineages face different selection pressures
161
Convergent evolution
Occurs when distantly related species face similar selection pressures, which results in similar phenotypes
162
Parallel evolution
Occurs when closely related species experience similar selection pressures, which leads to similar phenotypes over time
163
What is the difference between convergent and parallel evolution?
Convergent evolution starts with distantly related species, while parallel evolution starts with closely related species
164
What is reproductive isolation?
Reproductive isolation is a mechanism that prevents interbreeding between different species.
165
True or False: Reproductive isolation can occur before fertilization.
True
166
Fill in the blank: The two main types of reproductive isolation are ________ and ________.
prezygotic; postzygotic
167
What is a prezygotic barrier?
A prezygotic barrier is a reproductive barrier that occurs before fertilization, preventing the formation of a zygote.
168
Give an example of a prezygotic barrier.
Temporal isolation, where species breed at different times.
169
What is a postzygotic barrier?
A postzygotic barrier is a reproductive barrier that occurs after fertilization, affecting the viability or fertility of the offspring.
170
True or False: Hybrid inviability is a type of prezygotic barrier.
False
171
Multiple Choice: Which of the following is NOT a type of prezygotic barrier? A) Habitat isolation B) Behavioral isolation C) Hybrid sterility D) Mechanical isolation
C) Hybrid sterility
172
What is mechanical isolation?
Mechanical isolation occurs when differences in reproductive organs prevent mating.
173
Fill in the blank: Hybrid ________ occurs when hybrids are produced but do not survive to maturity.
inviability
174
What role does geographical isolation play in reproductive isolation?
Geographical isolation prevents species from mating due to physical barriers like mountains or rivers.
175
True or False: Behavioral isolation can occur when different species have different mating rituals.
True
176
Multiple Choice: Which of the following is a postzygotic barrier? A) Temporal isolation B) Habitat isolation C) Hybrid breakdown D) Mechanical isolation
C) Hybrid breakdown
177
What is temporal isolation?
Temporal isolation occurs when species breed at different times of the day or year.
178
Fill in the blank: In ________ isolation, two species may occupy the same area but do not mate because they have different mating calls.
behavioral
179
What is hybrid sterility?
Hybrid sterility occurs when hybrids are produced but are sterile and cannot reproduce.
180
True or False: Reproductive isolation can lead to speciation.
True
181
Multiple Choice: Which process is directly influenced by reproductive isolation? A) Natural selection B) Genetic drift C) Speciation D) All of the above
D) All of the above
182
What is gametic isolation?
Gametic isolation occurs when sperm and egg from different species are incompatible and cannot fertilize.
183
Fill in the blank: ________ isolation can prevent mating even when species live in the same area.
Behavioral
184
What happens during hybrid breakdown?
In hybrid breakdown, the first-generation hybrids are viable and fertile, but their offspring are inviable or sterile.
185
True or False: All forms of reproductive isolation are equally effective.
False
186
What is the significance of reproductive isolation in evolutionary biology?
Reproductive isolation is crucial for the formation of new species and the maintenance of species boundaries.
187
Fill in the blank: The concept of reproductive isolation helps explain the process of ________ in evolution.
speciation
188
Multiple Choice: Which type of isolation involves the timing of reproduction? A) Mechanical isolation B) Temporal isolation C) Habitat isolation D) Gametic isolation
B) Temporal isolation
189
What is speciation?
The process by which new species arise.
190
True or False: Speciation can occur through both allopatric and sympatric mechanisms.
True
191
Fill in the blank: The rate of speciation is influenced by factors such as __________, environmental changes, and genetic diversity.
geographic isolation
192
Multiple Choice: Which of the following factors can increase the rate of speciation? A) Climate stability B) Habitat fragmentation C) Genetic uniformity D) Limited resources
B) Habitat fragmentation
193
What role does genetic drift play in speciation?
Genetic drift can lead to changes in allele frequencies in isolated populations, contributing to speciation.
194
What is the significance of adaptive radiation in speciation?
Adaptive radiation leads to rapid speciation as organisms diversify to fill various ecological niches.
195
What is punctuated equilibrium?
A model of speciation that proposes species remain stable for long periods, interrupted by brief periods of rapid change.
196
What is a key factor that can lead to increased rates of speciation in island ecosystems?
Isolation from mainland populations.
197
True or False: Environmental changes can trigger speciation events.
True
198
What is the role of sexual selection in speciation?
Sexual selection can lead to reproductive isolation and divergence between populations.
199
What is parapatric speciation?
Speciation that occurs when populations are adjacent to each other but occupy different habitats.
200
True or False: Evolutionary pressures can slow down the rate of speciation.
True
201
What does the term 'species' refer to in the context of speciation?
A group of organisms that can interbreed and produce fertile offspring.
202
What is the importance of ecological niches in speciation?
Different niches can lead to resource partitioning and reproductive isolation.
203
What is the significance of reproductive barriers in speciation?
Reproductive barriers prevent interbreeding between populations, facilitating speciation.
204
What is genetic variation?
Genetic variation refers to the differences in DNA sequences among individuals within a population.
205
True or False: Genetic variation is essential for evolution.
True
206
Name one source of genetic variation.
Mutations
207
Fill in the blank: Genetic variation can arise from _______ during meiosis.
crossing over
208
Multiple choice: Which of the following is NOT a source of genetic variation? A) Mutations B) Genetic drift C) Environmental factors D) Artificial selection
C) Environmental factors
209
What role do mutations play in genetic variation?
Mutations introduce new alleles into a population, creating variation.
210
True or False: Genetic drift can lead to a loss of genetic variation.
True
211
What is gene flow?
Gene flow is the transfer of genetic material between populations through migration.
212
What is the impact of sexual reproduction on genetic variation?
Sexual reproduction increases genetic variation through the combination of alleles from two parents.
213
Multiple choice: Which of the following can introduce new genetic material into a population? A) Mutation B) Gene flow C) Sexual reproduction D) All of the above
D) All of the above
214
True or False: Cloning reduces genetic variation.
True
215
What is the significance of polyploidy in genetic variation?
Polyploidy can create new species and increase genetic diversity.
216
Fill in the blank: _______ can create new alleles by altering the DNA sequence.
Mutations
217
What is the difference between somatic and germline mutations?
Somatic mutations occur in non-reproductive cells, while germline mutations occur in reproductive cells and can be passed to offspring.
218
Multiple choice: Which mechanism can result in the establishment of new alleles in a population? A) Genetic drift B) Natural selection C) Mutation D) All of the above
D) All of the above
219
True or False: Natural selection can increase the frequency of beneficial mutations in a population.
True
220
Fill in the blank: The process of _______ results in the formation of gametes with unique combinations of alleles.
meiosis
221
What is the role of recombination in genetic variation?
Recombination shuffles alleles during meiosis, creating new combinations of genes.
222
Multiple choice: Which type of mutation involves the replacement of one nucleotide with another? A) Insertion B) Deletion C) Substitution D) Duplication
C) Substitution
223
True or False: Genetic variation is only important for species that reproduce sexually.
False
224
What is the term for the movement of individuals between populations that can increase genetic diversity?
Migration
225
Fill in the blank: The _______ hypothesis suggests that variation is essential for adaptation to changing environments.
variability
226
True or False: Genetic variation is essential for a population's ability to adapt to environmental changes.
True
227
What can lead to the loss of genetic variation in a population?
Factors such as genetic drift, inbreeding, and habitat destruction can lead to the loss of genetic variation.
228
Fill in the blank: The _____ effect is a phenomenon where a small population's genetic diversity decreases due to random sampling of alleles.
bottleneck
229
What is the founder effect?
The founder effect occurs when a small number of individuals from a larger population establish a new population, leading to reduced genetic diversity.
230
Multiple Choice: Which of the following is a consequence of loss of genetic variation? A) Increased adaptability B) Increased susceptibility to diseases C) Enhanced reproduction D) None of the above
B) Increased susceptibility to diseases
231
True or False: Inbreeding can increase genetic variation in a population.
False
232
What role does natural selection play in genetic variation?
Natural selection can promote certain alleles in a population, potentially reducing genetic variation if specific traits are favored.
233
Fill in the blank: The loss of genetic variation can lead to a decrease in a population's _____ ability.
adaptive
234
What is one method used to measure genetic variation in a population?
One method is to analyze the allele frequencies of specific genes within the population.
235
Multiple Choice: Which of the following populations is likely to have the highest genetic variation? A) A small isolated island population B) A large, interconnected population C) A population that has recently experienced a bottleneck D) All of the above
B) A large, interconnected population
236
True or False: Loss of genetic variation can make populations more vulnerable to extinction.
True
237
What is one consequence of habitat fragmentation on genetic variation?
Habitat fragmentation can isolate populations, leading to inbreeding and a reduction in genetic diversity.
238
Fill in the blank: The concept of genetic _____ refers to the total number of different alleles within a population.
diversity
239
What is the impact of climate change on genetic variation?
Climate change can alter habitats, leading to changes in selection pressures and potential loss of genetic variation.
240
Multiple Choice: Which of the following strategies can help conserve genetic variation? A) Habitat restoration B) Captive breeding programs C) Genetic monitoring D) All of the above
D) All of the above
241
True or False: Loss of genetic variation can result in an increase in deleterious traits within a population.
True
242
how does gene flow relate to genetic variation?
can increase genetic variation by introducing new alleles.
243
Fill in the blank: Genetic _____ is often measured using molecular markers such as microsatellites or SNPs.
variation
244
What is the significance of maintaining genetic variation in agriculture?
Maintaining genetic variation in agriculture is crucial for crop resilience, disease resistance, and adaptability to changing climates.
245
Multiple Choice: In which scenario would genetic drift be most pronounced? A) Large populations B) Small populations C) Diverse habitats D) None of the above
B) Small populations
246
True or False: Hybridization can sometimes increase genetic variation in a population.
True
247
What is one potential benefit of genetic diversity in conservation efforts?
Genetic diversity can enhance the resilience of species to environmental changes and diseases.
248
Fill in the blank: The _____ of genetic variation can lead to a phenomenon known as 'inbreeding depression.'
loss
249
What is the Hardy-Weinberg principle?
A principle that describes the genetic variation in a population that is not evolving.
250
List the five conditions required for a population to be in Hardy-Weinberg equilibrium.
no mutations, random mating, no natural selection, extremely large population size, and no gene flow.
251
True or False: The Hardy-Weinberg principle applies to populations that are evolving.
False.
252
What is the equation used in the Hardy-Weinberg principle?
p² + 2pq + q² = 1.
253
In the Hardy-Weinberg equation, what does 'p' represent?
The frequency of the dominant allele.
254
In the Hardy-Weinberg equation, what does 'q' represent?
The frequency of the recessive allele.
255
If p = 0.7, what is q?
0.3.
256
What does '2pq' represent in the Hardy-Weinberg equation?
The frequency of heterozygous individuals.
257
Fill in the blank: The Hardy-Weinberg principle assumes that allele frequencies will remain ______ over generations.
constant.
258
What is the significance of a population being in Hardy-Weinberg equilibrium?
It serves as a null hypothesis for studying evolutionary processes.
259
True or False: Genetic drift can disrupt Hardy-Weinberg equilibrium.
True.
260
What is gene flow?
The transfer of alleles or genes from one population to another.
261
What effect does natural selection have on Hardy-Weinberg equilibrium?
It disrupts equilibrium by favoring certain alleles over others.
262
Multiple Choice: Which of the following does NOT affect the Hardy-Weinberg equilibrium? A) Mutation B) Random mating C) Large population size D) Gene flow
C) Large population size.
263
If a population has allele frequencies of p = 0.6 and q = 0.4, what is the expected frequency of homozygous recessive individuals?
0.16.
264
What role does random mating play in the Hardy-Weinberg principle?
It ensures that individuals pair by chance, not by genotype.
265
True or False: The Hardy-Weinberg principle can be used to predict genotypic frequencies.
True.
266
What is the expected frequency of homozygous dominant individuals if p = 0.5?
0.25.
267
Fill in the blank: A population that is not in Hardy-Weinberg equilibrium is likely experiencing ______.
evolution.
268
What is the impact of small population size on Hardy-Weinberg equilibrium?
It increases the effects of genetic drift, leading to changes in allele frequencies.
269
True or False: The Hardy-Weinberg principle can be applied to all populations regardless of size.
False.
270
How can scientists use the Hardy-Weinberg principle in conservation biology?
To assess genetic diversity and the health of populations.
271
What is the relationship between Hardy-Weinberg equilibrium and genetic diversity?
Equilibrium indicates no change in genetic diversity over generations.
272
If a population is found to have allele frequencies that change over time, what can be inferred?
The population is not in Hardy-Weinberg equilibrium.
273
What does the term 'mutation' refer to in the context of the Hardy-Weinberg principle?
A change in the DNA sequence that can introduce new alleles.
274
___ can lead to diverse phenotypes within a population.
genetic polymorphism
