Biological Evolution Exam 2
- 1.
Where did modern humans originate?
- A.
In Europe
- B.
In Africa
- C.
In Asia
- D.
As a large population across the entire old world
Correct Answer
B. In AfricaExplanation
Modern humans originated in Africa. This is supported by extensive scientific evidence, including fossil records and genetic studies. The oldest known Homo sapiens fossils have been found in Africa, dating back around 300,000 years. Additionally, genetic studies have shown that all modern humans outside of Africa can trace their ancestry back to a single population that originated in Africa. This supports the theory of the "Out of Africa" migration, which suggests that modern humans first evolved in Africa and then spread to other parts of the world.Rate this question:
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- 2.
What evidence refutes the multiregional hypothesis regarding the origin of modern humans?
- A.
Human populations from Africa have much more mitochondrial diversity than populations from other areas of the world.
- B.
There is evidence of introgression between modern humans and other hominin species.
- C.
Not all hominin species are part of the direct lineage leading to modern humans.
- D.
Fossils of homonin species dating to nearly 2 million years ago can be found at various sites across the old world.
Correct Answer
A. Human populations from Africa have much more mitochondrial diversity than populations from other areas of the world.Explanation
The fact that human populations from Africa have much more mitochondrial diversity than populations from other areas of the world refutes the multiregional hypothesis regarding the origin of modern humans. This is because the multiregional hypothesis suggests that modern humans evolved simultaneously in different regions and interbred, leading to a continuous gene flow between populations. However, the higher mitochondrial diversity in African populations indicates that they have a longer and more diverse evolutionary history, suggesting that modern humans originated in Africa and then migrated to other regions, rather than evolving independently in multiple regions.Rate this question:
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- 3.
What are the odds that you are genetically identical to a full sibling who is not your monozygotic (identical) twin?
- A.
1 out of 23
- B.
1 out of 32.6
- C.
1 out of 7.1 billion
- D.
> 1 out of 76 trillion
Correct Answer
D. > 1 out of 76 trillionExplanation
The odds of being genetically identical to a full sibling who is not your monozygotic twin are extremely low. This is because the chances of inheriting the exact same combination of genes from both parents are very slim. With a vast number of possible gene combinations and variations, the likelihood of two siblings being genetically identical without being monozygotic twins is incredibly rare. Therefore, the correct answer is 1 out of 76 trillion.Rate this question:
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- 4.
Why did it take so long to unify the ideas of natural selection and Mendelian genetics?
- A.
Darwin’s ideas were superseded by Lamarck’s until Weismann’s cell theory disproved the likelihood of common spontaneous generation.
- B.
Mathematical model of sufficient complexity couldn’t be developed before the advent of modern computers.
- C.
The importance of Mendel’s work on genetic inheritance was largely ignored for nearly 80 years.
- D.
The ideas are too disparate and common ground was impossible until the theory of uniformitarianism provided a way to merge the two.
Correct Answer
C. The importance of Mendel’s work on genetic inheritance was largely ignored for nearly 80 years.Explanation
The unification of natural selection and Mendelian genetics took a long time because Mendel's work on genetic inheritance was largely ignored for nearly 80 years. This means that the significance and relevance of Mendel's findings were not recognized or appreciated, which hindered the integration of his ideas with Darwin's theory of natural selection. The lack of attention towards Mendel's work delayed the understanding and acceptance of the relationship between genetics and evolution.Rate this question:
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- 5.
Which of the following best describes the hypothesis of Thomas Malthus and his work on population growth when applied to the human population over the last two hundred years?
- A.
The human population, unlike most populations, doesn’t grow exponentially and so we have avoided the problem of not having enough resources for our population.
- B.
The “green revolution” has allowed our agricultural production to keep up with the exponential growth of the human population.
- C.
Wars, famines and genocide have prevented the human population from growing exponentially.
- D.
Because of disease and it’s impact on the early homonin species we are only now beginning to experience the conflict between population size and resource availability.
Correct Answer
B. The “green revolution” has allowed our agricultural production to keep up with the exponential growth of the human population. -
- 6.
What are the two key components of cell theory? (mark both answers)
- A.
All living organisms are made up of cells
- B.
Cell frequently spontaneously generate from dead, organic matter
- C.
All cells come from the division of other, pre-existing cells
- D.
Meiosis generates much less complexity of cell than mitosis
- E.
Eukaryotic cells are much better adapted to harsh enviroments than bacteria cells
Correct Answer(s)
A. All living organisms are made up of cells
C. All cells come from the division of other, pre-existing cellsExplanation
The two key components of cell theory are that all living organisms are made up of cells and that all cells come from the division of other, pre-existing cells.Rate this question:
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- 7.
Because the genetic code is degenerate _______________.
- A.
It's necessary that cells have proof-reading mechanisms to prevent rampant mutation
- B.
Human genes can be inserted into bacterial genomes
- C.
Multiple codons are synonymous: they code for the same amino acids
- D.
Cells with too many mutation go through apoptosis
Correct Answer
C. Multiple codons are synonymous: they code for the same amino acidsExplanation
The genetic code is degenerate, which means that multiple codons can code for the same amino acids. This allows for redundancy in the genetic code and provides a buffer against mutations. If a mutation occurs in a codon, there is a chance that the same amino acid can still be encoded by a different codon. This redundancy helps to prevent drastic changes in the amino acid sequence of proteins, which could have detrimental effects on cellular function.Rate this question:
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- 8.
The lower the mutational rate of a species the more successful it is.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
The given statement is false. The success of a species is not solely determined by its mutational rate. Other factors such as adaptability, genetic diversity, and environmental conditions also play a crucial role in the success of a species. A lower mutational rate may limit the species' ability to adapt to changing environments and may hinder genetic diversity, which can ultimately reduce its chances of survival and success.Rate this question:
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- 9.
On average, which of the following types of point mutations would have the largest effect on the phenotype of an organism?
- A.
An in/del in the protein coding sequence of a gene
- B.
A synonymous substitution in the coding sequence of a gene
- C.
An in/del in the non protein coding sequence of an organisms genome
- D.
A missense substitution in the coding sequence of a gene
Correct Answer
A. An in/del in the protein coding sequence of a geneExplanation
An in/del in the protein coding sequence of a gene would have the largest effect on the phenotype of an organism because it involves the insertion or deletion of nucleotides in the coding sequence. This can cause a frameshift mutation, where the reading frame of the gene is altered, leading to a completely different amino acid sequence being produced. This can result in a non-functional or partially functional protein, leading to significant changes in the organism's phenotype. In contrast, a synonymous substitution in the coding sequence would not change the amino acid sequence, an in/del in the non protein coding sequence may not have a direct impact on protein function, and a missense substitution would only alter a single amino acid in the protein sequence.Rate this question:
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- 10.
Which of the following mutations would be the most likely to lead to the creation of paralogous gene copies?
- A.
A synonymous substitution in the coding sequence of a gene
- B.
Translocation
- C.
Inversion
- D.
Duplication
Correct Answer
D. DuplicationExplanation
Duplication would be the most likely mutation to lead to the creation of paralogous gene copies. This is because duplication involves the replication of a gene, resulting in multiple copies of the same gene. Over time, these duplicated genes can undergo further mutations and diverge in sequence and function, leading to the creation of paralogous gene copies. In contrast, synonymous substitutions, translocations, and inversions do not directly result in the creation of additional gene copies.Rate this question:
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- 11.
The phenotype of an organism is determined by both its genotype and its ______________.
- A.
Environment
- B.
Population size
- C.
Cellular dispersal rate
- D.
Adaptation coefficient
Correct Answer
A. EnvironmentExplanation
The phenotype of an organism is determined by both its genotype and its environment. The genotype refers to the genetic makeup of an organism, which influences the traits it inherits. However, the expression of these traits can be influenced by the environment in which the organism lives. Environmental factors such as temperature, light, nutrition, and social interactions can all impact how genes are expressed and ultimately shape the phenotype of an organism. Therefore, the environment plays a crucial role in determining the observable characteristics of an organism.Rate this question:
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- 12.
In a protein coding sequence which position of the codon tends to accumulate the most mutations?
- A.
First
- B.
Second
- C.
Third
- D.
Fourth
Correct Answer
C. ThirdExplanation
In a protein coding sequence, the third position of the codon tends to accumulate the most mutations. This is because the third position of the codon is often referred to as the "wobble position," where there is more flexibility in the genetic code. Mutations in this position are more likely to be synonymous, meaning they do not change the amino acid that is coded for. Therefore, these mutations are often tolerated and can accumulate over time without causing significant changes in the protein's function.Rate this question:
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- 13.
Most natural populations have high levels of genetic diversity.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Genetic diversity refers to the variety of genetic traits within a population. It is important for the survival and adaptation of a population to changing environments. High levels of genetic diversity provide a larger pool of genetic variations, increasing the chances of individuals having traits that are beneficial for their survival. This allows for better adaptation to environmental changes, resistance to diseases, and overall population stability. Therefore, it is generally true that most natural populations have high levels of genetic diversity.Rate this question:
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- 14.
A trait that is affected by many different genes is ____________.
- A.
Pleiotropic
- B.
Polygenic
- C.
Always in H-W equilibrium
- D.
Not subject to natural selection
Correct Answer
B. PolygenicExplanation
Polygenic traits are influenced by multiple genes. These genes may interact with each other and with the environment to determine the expression of the trait. Examples of polygenic traits include height, skin color, and intelligence. Unlike pleiotropic traits, which are single genes that affect multiple traits, polygenic traits are influenced by multiple genes. The answer "polygenic" is the correct choice because it accurately describes a trait that is affected by many different genes.Rate this question:
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- 15.
What are the three components of a population that must be present for evolution via natural selection? (mark all three)
- A.
Variation between individuals in the population
- B.
Fitness difference between genetic variants
- C.
Effective population size larger than census population size
- D.
Meiotic cell division in at least some cells
- E.
Some of the variation must be heritable
Correct Answer(s)
A. Variation between individuals in the population
B. Fitness difference between genetic variants
E. Some of the variation must be heritableExplanation
The three components of a population that must be present for evolution via natural selection are variation between individuals in the population, fitness difference between genetic variants, and some of the variation must be heritable. Variation between individuals allows for different traits to be present in a population, which can be selected for or against based on their fitness. Fitness difference between genetic variants refers to how certain traits may confer advantages or disadvantages in survival and reproduction. Lastly, for natural selection to occur, some of the variation must be heritable, meaning that traits can be passed down from one generation to the next.Rate this question:
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- 16.
Having leaves modified into species is an adaptation
- A.
True
- B.
False
- C.
Impossible to tell without further information. Adaptations are determined by the environment, so what might be an adaptation in one area could be detrimental in another.
Correct Answer
C. Impossible to tell without further information. Adaptations are determined by the environment, so what might be an adaptation in one area could be detrimental in another.Explanation
The statement suggests that having leaves modified into species is an adaptation, but without further information about the specific environment and context, it is impossible to determine whether this is true or false. Adaptations are dependent on the environment, so what may be considered an adaptation in one area could be disadvantageous in another. Therefore, without additional details, it is impossible to make a definitive conclusion.Rate this question:
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- 17.
Evidence from long running selection experiments in E. coli bacteria suggests that two independent, but identical evolutionary experiments would _____________________.
- A.
Have significantly different outcomes due to the unpredictability of mutations
- B.
Have the exact same outcome
- C.
Have significantly different outcomes due to low fidelity of RNA translation
- D.
Violate the Heisenberg uncertainty principle
Correct Answer
A. Have significantly different outcomes due to the unpredictability of mutationsExplanation
Long running selection experiments in E. coli bacteria have shown that mutations, which are the driving force of evolution, are unpredictable. This means that even if two identical evolutionary experiments were conducted, they would have significantly different outcomes. The unpredictability of mutations leads to genetic variations that can result in different adaptations and traits, ultimately leading to different outcomes in the evolutionary process.Rate this question:
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- 18.
Which of the following is the best example of antagonistic pleiotropy?
- A.
When two organisms compete for the same resource rather than sharing.
- B.
A mutation in a gene that allows a bacterium to resist an antibiotic, but makes it grow slightly slower.
- C.
An individual that has a higher level of fitness due to an exaptation.
- D.
Two species adapted to different environments due to a different number of chromosomes.
Correct Answer
B. A mutation in a gene that allows a bacterium to resist an antibiotic, but makes it grow slightly slower.Explanation
An example of antagonistic pleiotropy is when a mutation in a gene allows a bacterium to resist an antibiotic, but at the same time, it causes the bacterium to grow slightly slower. This is because the mutation provides a benefit (antibiotic resistance) but also comes with a cost (slower growth). This trade-off is a classic example of antagonistic pleiotropy, where a single gene has multiple effects that are beneficial in one aspect but detrimental in another.Rate this question:
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- 19.
Which of the following statements best describes the ability of an owl to turn its head 180° around?
- A.
This is an exaptation for its nocturnal life style.
- B.
This is not an adaptation and is present in all birds.
- C.
This is an adaptation that compensates for the trade-off imposed by good binocular vision.
- D.
This is a pleiotropic effect of genes that control the development of feather morphology.
Correct Answer
C. This is an adaptation that compensates for the trade-off imposed by good binocular vision.Explanation
The ability of an owl to turn its head 180° around is an adaptation that compensates for the trade-off imposed by good binocular vision. This means that while owls have excellent binocular vision, their eyes are fixed in their sockets, limiting their field of view. By being able to rotate their heads, owls can compensate for this limitation and have a wider range of vision, which is beneficial for their nocturnal lifestyle and hunting.Rate this question:
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- 20.
How many different groups of animals have independently evolved true flight?
- A.
2
- B.
3
- C.
4
- D.
5
Correct Answer
C. 4Explanation
There are four different groups of animals that have independently evolved true flight. These groups are insects, birds, bats, and pterosaurs. Insects, such as bees and butterflies, have developed wings that allow them to fly. Birds have feathers and wings that enable them to fly. Bats are the only mammals capable of sustained flight, thanks to their specialized wing structure. Pterosaurs were flying reptiles that lived during the time of dinosaurs and had wings made of skin. All four of these groups have evolved the ability to fly through separate evolutionary processes.Rate this question:
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- 21.
What is the best way to assess whether or not two complex structures are homologous?
- A.
Look at the fine details of the structure to see how similar they truly are.
- B.
Determine which genes are responsible for the development of the structure.
- C.
Estimate the genome size of each organism, if they are not significantly different in size than the structures are most likely homologous.
- D.
Map the evolutionary origin of the structures onto a well-supported phylogeny.
Correct Answer
D. Map the evolutionary origin of the structures onto a well-supported phylogeny.Explanation
The best way to assess whether or not two complex structures are homologous is to map the evolutionary origin of the structures onto a well-supported phylogeny. This involves comparing the structures in question to the evolutionary history of related organisms and determining if they share a common ancestor. By analyzing the phylogeny, we can identify patterns of evolutionary relationships and determine if the structures are likely to be homologous or not.Rate this question:
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- 22.
Which group serves as the best model for the evolution of the complex eye and why?
- A.
Crustaceans, because their eyes have multiple lenses that work together to convey information to the brain.
- B.
Annelids, because they are able to regenerate their eyes when they lose them.
- C.
Vertebrates, because they have the most complex eye of any animal.
- D.
Mollusks, because different species have photoreceptors that vary greatly in complexity and these demonstrate some of the intermediate steps from simple to complex.
Correct Answer
D. Mollusks, because different species have photoreceptors that vary greatly in complexity and these demonstrate some of the intermediate steps from simple to complex.Explanation
Mollusks are the best model for the evolution of the complex eye because different species of mollusks have photoreceptors that vary greatly in complexity. This variation in complexity demonstrates some of the intermediate steps from a simple eye to a more complex one. This suggests that mollusks have undergone a gradual evolution of their visual system, making them a suitable model for understanding how complex eyes evolved.Rate this question:
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- 23.
What is the result of co-option of an already present gene to perform an additional new function?
- A.
This results in pleiotropy of the gene and an additional constraint on its evolution.
- B.
This results in a shift of the genetic code with a tendency to have fewer synonymous mutations.
- C.
This results in a reduction in the structure and complexity of the chromosomes.
- D.
This results in increased genetic diversity and is the first step towards speciation.
Correct Answer
A. This results in pleiotropy of the gene and an additional constraint on its evolution. -
- 24.
Which of the following would not violate H-W equilibrium?
- A.
Natural selection for one allele
- B.
A small population size
- C.
Immigration of individuals with a particular genotype
- D.
Non-random mating
- E.
Independent assortment of alleles during meiosis
Correct Answer
E. Independent assortment of alleles during meiosisExplanation
Independent assortment of alleles during meiosis would not violate H-W equilibrium. H-W equilibrium assumes that certain conditions are met, including random mating and no influence of external factors such as natural selection, migration, or small population size. Independent assortment of alleles during meiosis refers to the random distribution of different alleles into gametes, which is consistent with the assumption of random mating. Therefore, it does not disrupt the equilibrium.Rate this question:
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- 25.
You randomly sample one thousand individuals from a population of butterflies (sexually reproducing, diploid animals) and find the following distribution of genotypes: AA: 160Aa: 480aa: 360What are the allele frequencies for this population?
- A.
A: 0.3 a: 0.7
- B.
A: 0.5 a: 0.5
- C.
A: 0.9 a: 0.1
- D.
A: 0.4 a: 0.6
Correct Answer
D. A: 0.4 a: 0.6Explanation
The allele frequencies can be calculated by dividing the number of alleles by the total number of alleles in the population. In this case, there are 160 AA individuals, which represents 160 x 2 = 320 A alleles. There are 480 Aa individuals, which represents 480 x 1 = 480 A alleles. And there are 360 aa individuals, which represents 360 x 0 = 0 A alleles. Therefore, the total number of A alleles is 320 + 480 + 0 = 800. The total number of alleles in the population is 800 + 800 = 1600. The frequency of A alleles is 800/1600 = 0.5, and the frequency of a alleles is 1 - 0.5 = 0.5.Rate this question:
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- 26.
You randomly sample one thousand individuals from a population of butterflies (sexually reproducing, diploid animals) and find the following distribution of genotypes: AA: 160Aa: 480aa: 360The above population is in Hardy-Weinberg Equilibrium.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The distribution of genotypes in the sampled population follows the expected proportions under Hardy-Weinberg Equilibrium. In a population that is in Hardy-Weinberg Equilibrium, the frequencies of genotypes remain constant from generation to generation if certain conditions are met, such as no selection, no mutation, no migration, random mating, and a large population size. Since the sampled population's genotype distribution matches the expected proportions, it suggests that the population is in Hardy-Weinberg Equilibrium. Therefore, the answer is true.Rate this question:
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- 27.
You come back after three years and find the following distributions of genotypes in the population:AA: 50Aa: 700aa: 250Evolution occurred for this gene between the original population and the population three years later.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The given distribution of genotypes in the population after three years shows a change from the original population. This indicates that evolution has occurred for this gene. The increase in the number of individuals with the Aa genotype suggests that there has been a shift in the gene frequencies, which is a key aspect of evolution. Therefore, the correct answer is true.Rate this question:
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- 28.
Which of the following is the most likely explanation for the pattern observed when comparing the original population of butterflies above to the population three years later?
- A.
No evolution occurred, because the forces keeping the population out of H-W equilibrium were constant.
- B.
Evolution occurred, this was caused by random emigration of individual butterflies.
- C.
No evolution occurred, the population was originally at H-W equilibrium and remained there.
- D.
Evolution occurred, this was caused by a directional natural selection force
- E.
Evolution occurred, this was caused by an overdominant natural selection force
Correct Answer
E. Evolution occurred, this was caused by an overdominant natural selection forceExplanation
The most likely explanation for the pattern observed when comparing the original population of butterflies to the population three years later is that evolution occurred due to an overdominant natural selection force. This means that individuals with heterozygous genotypes had a higher fitness compared to individuals with homozygous genotypes, leading to an increase in genetic diversity within the population. This suggests that the forces driving evolution were not constant and resulted in a change in the population over time.Rate this question:
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- 29.
A random sample from a population of vines (sexually reproducing, diploid) has a genotype and phenotype distribution of: AA: 250, red flowers Aa: 500, pink flowers aa: 250, white flowersIf each flower color has a different species of bee acting as a pollinator what is the most likely distribution of phenotypes in the next generation?
- A.
100 red flowering vines, 100 pink flowering vines, 800 white flowering vines
- B.
375 red flowering vines, 250 pink flowering vines, 375 white flowering vines
- C.
250 red flowering vines, 500 pink flowering vines, 250 white flowering vines
- D.
50 red flowering vines, 900 pink flowering vines, 50 white flowering vines
Correct Answer
B. 375 red flowering vines, 250 pink flowering vines, 375 white flowering vinesExplanation
The most likely distribution of phenotypes in the next generation would be 375 red flowering vines, 250 pink flowering vines, and 375 white flowering vines. This is because the genotype and phenotype distribution in the current generation is Aa: 500, pink flowers, which means that the pink flowering trait is the most common. Therefore, it is likely that the pink flowering trait will be passed on to a significant portion of the next generation. Additionally, since the current generation has an equal number of AA: 250, red flowers and aa: 250, white flowers, it is likely that these traits will also be passed on in equal proportions to the next generation.Rate this question:
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- 30.
Which of the following population would suffer the most from inbreeding depression?
- A.
A population of frogs with strong disassortative mating.
- B.
A population of captive bred lizards that originated from 8 captured individuals.
- C.
Human descendants of 50 individuals who originally colonized an remote Pacific atoll.
- D.
A bacteria population founded by a single bacterium.
Correct Answer
B. A population of captive bred lizards that originated from 8 captured individuals.Explanation
Inbreeding depression occurs when individuals within a population mate with close relatives, leading to a decrease in fitness and genetic diversity. The population of captive bred lizards that originated from only 8 captured individuals would suffer the most from inbreeding depression. This is because the small founding population size limits genetic variation, increasing the chances of mating between close relatives and the expression of harmful recessive traits. In contrast, the other populations mentioned have either mechanisms (disassortative mating) or larger founding populations (human descendants, bacteria population) that help maintain genetic diversity and minimize the effects of inbreeding depression.Rate this question:
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- 31.
If all other conditions are identical, adaptive mutations that are dominant will become fixed more quickly than adaptive mutations that are recessive.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Adaptive mutations that are dominant will not necessarily become fixed more quickly than adaptive mutations that are recessive, even if all other conditions are identical. The fixation of a mutation depends on various factors such as the strength of selection, population size, and genetic drift. Dominant mutations may have a higher chance of being expressed phenotypically, but their fixation is not solely determined by dominance. Recessive mutations can still become fixed if they provide a significant adaptive advantage and are not lost due to genetic drift. Therefore, the statement is false.Rate this question:
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- 32.
In addition to genetics, what other factor has a major impact on the speed at which a beneficial allele will become fixed in a population?
- A.
Whether or not it is an adaptation
- B.
The rate of metabolism of the organism
- C.
The strength of selection for the beneficial allele
- D.
The number of chromosomes for individuals in the population
Correct Answer
C. The strength of selection for the beneficial alleleExplanation
The strength of selection for the beneficial allele has a major impact on the speed at which it will become fixed in a population. If the selection pressure is strong, meaning that the allele provides a significant advantage to the organism's survival or reproduction, it is more likely to spread quickly through the population and become fixed. On the other hand, if the selection pressure is weak, the allele may take longer to become fixed or may not become fixed at all. Therefore, the strength of selection is an important factor in determining the speed of allele fixation.Rate this question:
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- 33.
Which of the following represents a Hardy-Weinberg equation that has been modified to model the effect of natural selection on a population?
- A.
P2 + q2 + r2 + 2pq + 2pr + 2qr = 1
- B.
P2 + 2pq + q2 = 2
- C.
(p-3s)2 + 2(p-s)q + q2 = 1
- D.
P4 + 2p2q2 + q4 = 1
Correct Answer
C. (p-3s)2 + 2(p-s)q + q2 = 1Explanation
The given equation, (p-3s)2 + 2(p-s)q + q2 = 1, represents a modified Hardy-Weinberg equation that includes the effect of natural selection on a population. In this equation, 'p' represents the frequency of one allele, 's' represents the selection coefficient, and 'q' represents the frequency of the other allele. The equation accounts for the reduction in the frequency of the 'p' allele due to natural selection by subtracting '3s' from 'p'. It also includes the interaction between the 'p' and 'q' alleles through the term 2(p-s)q. Overall, this equation models the effect of natural selection on the genetic makeup of a population.Rate this question:
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- 34.
The bright, aposematic coloration of poison dart frogs is the result of __________________.
- A.
Positive frequency dependent selection
- B.
Epistatic interactions of multiple genes
- C.
Negative frequency dependent selection
- D.
Inbreeding
Correct Answer
A. Positive frequency dependent selectionExplanation
The bright, aposematic coloration of poison dart frogs is the result of positive frequency dependent selection. This means that the more common a particular coloration becomes in the population, the more advantageous it is for predators to recognize and avoid that coloration. As a result, individuals with the bright coloration have a higher chance of survival and reproduction, leading to an increase in the frequency of that coloration in the population over time.Rate this question:
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- 35.
What is the result of negative frequency dependant selection, such as that observed among male morphotypes in some dung beetle species?
- A.
Loss of genetic diversity due to fixation of one allele
- B.
Strong inbreeding depression
- C.
A balance point is reached and diversity of this behavior is maintained
- D.
The species naturally splits into two populations.This may be the beginning of speciation.
Correct Answer
C. A balance point is reached and diversity of this behavior is maintainedExplanation
Negative frequency dependent selection refers to a situation where the fitness of a particular phenotype decreases as its frequency in the population increases. In the case of male morphotypes in dung beetle species, this means that certain male traits become less advantageous as they become more common. As a result, a balance point is reached where the fitness of each morphotype is equalized, leading to the maintenance of diversity in this behavior. This balance point prevents the fixation of one allele and allows for the coexistence of multiple morphotypes within the population.Rate this question:
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- 36.
Which of the three types of frequency independent selection is of most interest to scientists studying speciation?
- A.
Underdominance
- B.
Directional
- C.
Overdominance
Correct Answer
A. UnderdominanceExplanation
Underdominance is the type of frequency independent selection that is of most interest to scientists studying speciation. Underdominance occurs when individuals with heterozygous genotypes have lower fitness compared to individuals with homozygous genotypes. This can lead to the maintenance of genetic variation within a population and potentially drive the formation of new species. By studying underdominance, scientists can gain insights into the mechanisms and processes involved in speciation.Rate this question:
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- 37.
A genetic mutation that may or may not lead to phenotypic diversity is an example of a new ____________.
- A.
Haplotype
- B.
Antangonistic pleiotropy
- C.
Epistatic interference
- D.
Polygenic trait
Correct Answer
A. HaplotypeExplanation
A haplotype refers to a set of genetic variations or mutations that are inherited together on the same chromosome. These variations can occur within a single gene or across multiple genes. In the context of the given question, a genetic mutation that may or may not lead to phenotypic diversity can be considered a haplotype because it represents a specific combination of genetic variations that can influence the expression of traits. However, it is important to note that not all haplotypes necessarily lead to phenotypic diversity, as some mutations may be silent or have no observable effect on the phenotype.Rate this question:
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- 38.
A characteristic, such as height on humans, controlled by many different genes is an example of a(n) ____________.
- A.
Haplotype
- B.
Antagonistic pleiotropy
- C.
Epistatic interference
- D.
Polygenic trait
Correct Answer
D. Polygenic traitExplanation
A characteristic, such as height on humans, controlled by many different genes is an example of a polygenic trait. This means that multiple genes contribute to the expression of the trait, and each gene may have a small additive effect on the overall phenotype. In the case of height, there are likely numerous genes involved, each with their own contribution to the final height of an individual.Rate this question:
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- 39.
Polygeny, coupled with differing environmental effects, most often results in _______________.
- A.
Overdominance
- B.
Continuous traits
- C.
Fixation of deleterious alleles
- D.
A reduction in the size of the genome
Correct Answer
B. Continuous traitsExplanation
Polygeny refers to the inheritance of traits that are controlled by multiple genes. When combined with differing environmental effects, this often leads to the development of continuous traits. Continuous traits are characteristics that show a wide range of variation, such as height or skin color, and are influenced by the interaction of multiple genes and environmental factors. This is in contrast to discrete traits, which are controlled by a single gene or a small number of genes and exhibit distinct categories, such as blood type or eye color.Rate this question:
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Feb 10, 2023Quiz Edited by
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Dec 09, 2014Quiz Created by
Vlgarza2008
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