Question 1

A farmer uses triazine herbicide to control pigweed in his field.For the first few years,the triazine works well and almost all the pigweed dies;but after several years,the farmer sees more and more pigweed.Which of these explanations best describes this observation?

Accepted Answer

Over time, the repeated use of the herbicide selected for triazine-resistant pigweed individuals, so the only surviving and reproducing pigweed were those that were resistant to triazine. This led to an increase in the proportion of triazine-resistant pigweed in the population.

Question 2

Which of the following statements is an example of typological thinking?

Accepted Answer

Typological thinking involves categorizing individuals or groups into broad, generalized categories based on perceived characteristics or stereotypes. Statement B exemplifies this kind of thinking by making sweeping generalizations about the physical characteristics and preferences of an entire gender. Statements A, C, and D do not exhibit typological thinking.

Question 3

Many crustaceans (e.g.,lobsters,shrimp,and crayfish)use their tails to swim,but crabs have reduced tails that curl under their shells and are not used in swimming.This is an example of

Accepted Answer

This is an example of a vestigial trait, which is a feature that has evolved to become smaller or non-functional because it is no longer needed. Crabs have adapted to move primarily using their walking legs, so their tails have become reduced and are no longer used for swimming.

Question 4

Your text discusses the evolution of antibiotic-resistant M.tuberculosis bacteria in a patient.Researchers discovered that the strain of M.tuberculosis taken from the dead patient has a point mutation in the rpoB gene that codes for part of the RNA polymerase enzyme.This mutant form of RNA polymerase does not normally function as well as the more common form,but a commonly used antibiotic called rifampin does not affect the mutant rpoB.A researcher places M.tuberculosis isolated from the patient a year before death (no rpoB mutation)in cell cultures with M.tuberculosis isolated from the dead patient (with rpoB mutation).Half the cell cultures contain just standard nutrients,and the other cell cultures contain rifampin in addition to the standard nutrients.After many cell generations,the researcher finds that

Accepted Answer

The presence of rifampin selects for the rpoB mutation because the mutant form of RNA polymerase is resistant to rifampin, allowing those bacteria to survive and proliferate. In the absence of rifampin, the non-mutant bacteria, which have a more efficient RNA polymerase, outcompete the mutant strain.

Question 5

Which of these conditions are always true of populations evolving due to natural selection? Condition 1: The population must vary in traits that are heritable.
Condition 2: Some heritable traits must increase reproductive success.
Condition 3: Individuals pass on all traits they acquire during their lifetime.

Accepted Answer

Condition 1 is necessary because natural selection can only act on traits that are heritable. 
Condition 2 is necessary because natural selection acts to increase the frequency of traits that increase reproductive success. 
Condition 3 is not always true; individuals do not pass on all traits acquired during their lifetime, as not all acquired traits are heritable.

Question 6

After the drought of 1977,researchers hypothesized that on Daphne Major,medium ground finches with large,deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits.If this hypothesis is true,what would you expect to observe if a population of these medium ground finches colonizes a nearby island where Tribulus cistoides is the primary available food in all years? Assume that (1)even the survivors of the 1977 drought sometimes had difficulty cracking the tough T.cistoides fruits and would eat other seeds when offered a choice,and (2)food availability is the primary limit on finch fitness on this new island.

Accepted Answer

If the primary food source is the tough Tribulus cistoides fruits, natural selection would favor finches with larger, deeper beaks that can crack these fruits more efficiently, leading to the evolution of larger, deeper beaks over time.

Question 7

Which of the following scientists argued that variation among individuals allows evolution to occur?

Accepted Answer

Wallace, a contemporary of Darwin, independently arrived at the concept of natural selection as the mechanism for evolution. He argued that variations among individuals within a population allowed for those that were better adapted to their environment to survive and reproduce, passing on their favorable traits to their offspring.

Question 8

The same basic internal organs (kidneys,stomach,heart,lungs)are found in frogs,birds,snakes.and rodents.This is primarily an example of

Accepted Answer

The presence of the same internal organs in different organisms indicates that they have a similar underlying structure, which is referred to as structural homology. It suggests that these organisms may have evolved from a common ancestor and have retained some of the structural features of their ancestor. Developmental homology refers to the similarity in developmental processes among different organisms. Genetic correlation refers to the correlation between two or more genetic traits. Inheritance of acquired characteristics suggests that traits acquired during an organism's lifetime can be passed on to its offspring, which is not supported by modern genetics.

Question 9

A farmer uses triazine herbicide to control pigweed in his field.For the first few years,the triazine works well and almost all the pigweed dies;but after several years,the farmer sees more and more pigweed,no matter how often he applies triazine.Which of these actions is most likely to solve the farmer's problem?

Accepted Answer

The farmer's problem is most likely due to the pigweed developing resistance to triazine herbicide. Using a different herbicide with a different mode of action is the best choice to control the resistant pigweed. Options A, C, and D are unlikely to solve the problem as they involve using more or the same herbicide that the pigweed has already developed resistance to.

Question 10

Radiometric dating is a technique used to determine the age of rocks.Geologists have used this technique to determine that

Accepted Answer

Radiometric dating techniques have shown that Earth is about 4.6 billion years old, and the earliest evidence of life on Earth is about 3.4 billion years old.

Question 11

Evolutionary theory predicts that species are related,not independent.Four of the following examples provide support for this prediction,but one is irrelevant.Which one of these examples does not support the claim that species are related?

Accepted Answer

This example is irrelevant to the claim that species are related, as it explains extinction due to an external event rather than evolutionary relationships between organisms.

Question 12

You sequence the genes that code for an important glycolytic enzyme in a moth,a mushroom,a worm,and an alga,and find a high degree of sequence similarity among these distantly related species.This is an example of

Accepted Answer

The high degree of sequence similarity among distantly related species indicates that these species share a common ancestor and have inherited these genes from that ancestor. This is an example of genetic homology. Structural homology refers to similarities in the structure of different species, whereas developmental homology refers to similarities in the developmental processes in different species. Analogy/convergent evolution refers to similarities in traits that have evolved independently in different species that are not closely related.

Question 13

Why was Darwin and Wallace's theory of evolution by natural selection revolutionary?

Accepted Answer

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it challenged the prevailing belief of the time that species were constant and unchanging. It emphasized the importance of variation and change within populations over time, leading to the development of new species. This idea was a major departure from previous biological thought and had profound implications for the study of biology and the understanding of the natural world.

Question 14

Why did Darwin argue that evidence of extinction supports the theory of evolution?

Accepted Answer

Darwin argued that evidence of extinction supports the theory of evolution because it shows that the number and types of species have changed over time. Extinction indicates that certain species were not able to adapt to changes in their environment and were therefore removed from the gene pool, while others were able to survive and reproduce. This process of natural selection leads to changes in the characteristics of the surviving populations, which can ultimately result in the emergence of new species.

Question 15

Which of the following has the highest Darwinian fitness?

Accepted Answer

Darwinian fitness is measured by an individual's ability to pass on their genes to future generations. The sperm donor in option C has fathered 52 children, therefore, his genes have a higher likelihood of being passed on compared to the other options.

Question 16

Gill pouches in chick,human,and house-cat embryos are an example of

Accepted Answer

Gill pouches in chick, human, and house-cat embryos are an example of developmental homology because they are structures that are present in different organisms during embryonic development and are modified in different ways to form different adult structures, such as gills in fish and lungs in mammals. Structural homology refers to similarities in adult structures, genetic homology refers to similarities in DNA sequences, and the inheritance of acquired characters is a discredited idea from early evolutionary theory that suggests that an organism can pass on traits acquired during its lifetime to its offspring.

Question 17

Who proposed that organisms could be organized into a great chain of being?

Accepted Answer

Aristotle proposed the concept of the Great Chain of Being. He believed that all living organisms could be arranged in a hierarchy from the simplest life forms at the bottom to the most complex at the top. This idea had a significant influence on biology and philosophy in the Middle Ages and Renaissance.

Question 18

Researchers have found fossils of Eocene horse species in Colorado.Deeper deposits contain smaller species,and more recent deposits contain larger species.How does this observation support the theory of evolution?

Accepted Answer

The observation that deeper deposits contain smaller species, and more recent deposits contain larger species supports the theory of evolution because it provides evidence that species change over time. This suggests that the horses evolved and adapted to their changing environments.

Question 19

Explain how one of the following supports the idea that species change through time: artificial selection,extinction,transitional forms,vestigial traits,or antibiotic resistance.

Accepted Answer

The answer of Explain how one of the following supports...

Question 20

Which of the following is the best modern definition of evolution?

Accepted Answer

Evolution refers to the change in the frequency of alleles in a population over time. This can result in the development of new species or the extinction of existing ones. The process of evolution is driven by various factors, including genetic mutations, natural selection, genetic drift, and gene flow. The other answer choices either do not accurately describe the process of evolution or are outdated concepts that have been disproven by scientific evidence.

Quiz 24: Evolution by Natural Selection