Question 1

Which publication by Charles Darwin outlines his theory for evolution?

Accepted Answer

"The Origin of Species" is the publication by Charles Darwin that outlines his theory for evolution.

Question 2

According to Darwin's theory of natural selection:
1)Individuals within a species vary with regards to heritable traits.
2)Individuals who have certain characteristics are more able to survive and reproduce.
3)Individuals who pass their traits down to offspring will eventually change the characteristics of the species.

Accepted Answer

Darwin's theory of natural selection states that there is variation within a species due to heritable traits, and individuals who possess certain advantageous characteristics are more likely to survive and reproduce. Over time, these advantageous traits become more common within the population, resulting in a change in the characteristics of the species. Therefore, all three statements are true and E is the correct answer.

Question 3

Which structure was examined by Dobzhansky and his collaborators,enabling the detection of variability underlying a phenotype?

Accepted Answer

Dobzhansky and his collaborators examined polytene chromosomes in Drosophila in order to detect variability underlying a phenotype. Polytene chromosomes are giant chromosomes that can be easily viewed under a microscope, and they revealed differences in chromosome structure and gene expression that underlie phenotypic variation.

Question 4

In the study of polytene chromosomes among Drosophila it was determined that:
1)Different arrangements predominated different geographical regions.
2)Frequencies of the arrangements changed seasonally.
3)Long-term changes in the frequencies of arrangements occur in some populations.

Accepted Answer

The statement discusses three findings about polytene chromosomes in Drosophila. First, different arrangements predominate different geographical regions. Second, frequencies of the arrangements change seasonally. Third, long-term changes in the frequencies of arrangements occur in some populations. Therefore, all three statements are correct, and the best choice is E ("All of these").

Question 5

Proteins that exhibit electrophoretic variation with at least two of the variants having frequencies greater than 1 percent in the population are known as

Accepted Answer

Proteins that exhibit electrophoretic variation with at least two of the variants having frequencies greater than 1 percent in the population are known as polymorphic. Monomorphic means there is no variation, amorphic means the gene is non-functional, and aneuplodic means there is an abnormal number of chromosomes. None of these options fit the description given, except for polymorphic.

Question 6

What did Darwin propose to be the driving force of evolution in nature?

Accepted Answer

Darwin proposed that natural selection is the driving force of evolution. He suggested that organisms with advantageous traits are more likely to survive and reproduce, passing on those traits to their offspring. Over time, this process leads to the gradual changes in species that we refer to as evolution. Migration, emigration, inbreeding, and random mating can all play a role in shaping evolution to some degree, but natural selection is the primary mechanism that drives it forward.

Question 7

Which of the following is not considered a polymorphism?

Accepted Answer

White eyes in Drosophila is not considered a polymorphism because it is a mutation that does not actively exist in the population. Polymorphism refers to the coexistence of two or more different forms of a gene or trait within a population. The other options listed demonstrate polymorphism.

Question 8

Darwin proposed that a species changes as a result of

Accepted Answer

Darwin proposed that a species changes as a result of generations of competition among individuals, a process he called natural selection. Those individuals with traits that are better suited to their environment are more likely to survive and reproduce, passing on those favorable traits to their offspring over time.

Question 9

Who is credited with proposing the original theory of evolution?

Accepted Answer

Charles Darwin is credited with proposing the original theory of evolution through natural selection, as outlined in his 1859 book "On the Origin of Species."

Question 10

The status of the Duffy polymorphism for blood type varies among

Accepted Answer

The Duffy polymorphism for blood type varies among human ethnic groups, but not necessarily within individual members of the same family, religious groups or inbred family groups.

Question 11

Which of the following would be the best example of polymorphisms changing in various environments?

Accepted Answer

The light and dark forms of the Peppered moth are a classic example of polymorphisms changing in response to environmental factors. The shift in coloration from light to dark occurred in response to the increase in pollution during the Industrial Revolution, which caused the trees to darken from soot. This allowed the dark forms of the moth to blend in and avoid predation, leading to a decrease in the frequency of the light form and an increase in the frequency of the dark form.

Question 12

Different forms of an enzyme encoded by different alleles of a gene are known as

Accepted Answer

Allozymes are different forms of an enzyme that are encoded by different alleles of the same gene, reflecting genetic variation within a population.

Question 13

Different colored bands on the shells of land snails would be classified as what type of variation?

Accepted Answer

The different colored bands on the shells of land snails would be considered phenotypic variation, as it is a visible trait that can be observed and compared among individuals. Molecular variation would refer to differences at the genetic level (such as DNA sequence), while chromosomal variation would refer to differences in the number or structure of chromosomes.

Question 14

Allozymes differ from each other by

Accepted Answer

Allozymes are variants of enzymes, which can differ from each other by one or more amino acids in their overall sequences. This variation in amino acid sequence can result in changes in the enzyme's function, stability, or regulation.

Question 15

Which of the following principles grounded Darwin's work and allowed for an explanation of how variations are inherited?
1)Wallace's theory of inheritance
2)Mendel's principles of inheritance
3)Morgan's principles of inheritance

Accepted Answer

Mendel's principles of inheritance were the basis for Darwin's work on how variations are inherited, as they provided an explanation for the pattern of inheritance of traits. This allowed Darwin to develop his theory of natural selection, which relied on genetic variation as the basis for evolution. Wallace was a contemporary of Darwin who independently developed a similar theory of evolution, but did not contribute to the understanding of inheritance in the same way that Mendel did. Morgan's principles of inheritance were developed later, and built upon Mendel's work in understanding the molecular basis of inheritance.

Question 16

What type of mutation created the different arrangements of banding patterns in the polytene chromosomes studied by Dobzhansky?

Accepted Answer

The different arrangements of banding patterns in the polytene chromosomes studied by Dobzhansky were the result of inversions, which involve a segment of DNA being reversed within a chromosome. This can alter the order of genes and other genetic material, thereby creating new combinations of traits.

Question 17

Which type of variation was first to be analyzed by naturalists and geneticists?

Accepted Answer

Phenotypic variation, or variation in physical traits, was the first type of variation analyzed by naturalists and geneticists, such as Charles Darwin and Gregor Mendel. They observed and studied variations in traits like flower color and pea shape, which were then later explained by genetic principles.

Question 18

In the study of polytene chromosomes among Drosophila it was determined that __________ selection plays an important role in maintaining chromosomal polymorphisms in nature.

Accepted Answer

Polytene chromosomes are a useful tool for studying chromosomal polymorphisms in Drosophila. Balancing selection is an important factor that maintains polymorphisms in natural populations, and studies of polytene chromosomes have shown evidence of this type of selection in maintaining chromosomal polymorphisms. Therefore, the correct answer is B) Balancing selection.

Question 19

Which of the following were not explained in Darwin's theory of evolution?
1)The origin of variation among individuals
2)How particular variants are inherited
3)How individuals are selected in nature to pass on their traits

Accepted Answer

Darwin's theory of evolution did not explain the origin of variation among individuals or how particular variants are inherited. However, it did explain how individuals are selected in nature to pass on their traits through the process of natural selection.

Question 20

Which of the following is a disadvantage of protein gel electrophoresis?
1)Nonsoluble,hydrophobic proteins cannot readily be analyzed.
2)It focuses on gene products rather than on the genes themselves.
3)It tells nothing about variation in the nongenic portion of a genome.

Accepted Answer

Protein gel electrophoresis has limitations including difficulty analyzing nonsoluble, hydrophobic proteins, focusing on gene products rather than genes themselves, and not providing information about variations in non-genic portions of the genome.

Quiz 24: Evolutionary Genetics