Q2W5 EALS Evolution

Multiple Choice

On the tree of life, the branch leading to animals is closer to fungi than it is to the branch leading to land plants. Which of the following statements is incorrect?

• Animals and land plants are more closely related to each other than either is to fungi.

• Animals and plants have a common ancestor.

• Fungi and animals have a common ancestor.

• Animals and fungi are more closely related to each other than animals are to land plants.

Multiple Choice

Evolution is often described as "the theme that ties together all aspects of biology."

This is because the process of evolution explains...

• how organisms become adapted to their environment

  the diversity of organisms

• why all organisms have characteristics in common.

• why distantly related organisms sometimes resemble one another.

• all of the choices are correct

Multiple Choice

Evolution occurs when...

• individuals in a population change over time in response to the environment

• the average value of trait in a population changes from one generation to the next

• Both choices are correct

Multiple Choice

Which of the following is NOT an example of evolution?

• Beak size in a population of birds becomes larger from one generation to the next because larger beaked birds had higher reproductive success and passed the trait to their offspring

• Over long periods of time, whales gradually lost their hind limbs

• When traveling to high altitude, human physiology changes to accommodate lower oxygen levels

• Antibiotic resistance of bacteria.

Multiple Choice

Evolution is often described as "the theme that ties together all aspects of biology."

This is because the process of evolution explains...

• how organisms become adapted to their environment

• the diversity of organisms

• why all organisms have characteristics in common.

• all of the choices are correct

• why distantly related organisms sometimes resemble one another.

Multiple Choice

Which of the following is NOT an example of evolution?

• Beak size in a population of birds becomes larger from one generation to the next because larger beaked birds had higher reproductive success and passed the trait to their offspring

• Over long periods of time, whales gradually lost their hindlimbs

• When traveling to high altitude, human physiology changes to accommodate lower oxygen levels

• All of the choices are examples of evolution

Multiple Choice

Evolution occurs when...

• individuals in a population change over time in response to the environment

• the average value of trait in a population changes from one generation to the next

• Both choices are correct

Multiple Choice

Cattle breeders have improved the quality of meat over the years by which process?

• artificial selection

• gene flow

• natural selection

• genetic drift

Multiple Choice

Which of these evolutionary agents is most consistent at causing populations to become better suited to their environments over the course of generations?

• Mutation

• Natural selection

• Gene flow

• Genetic drift

Multiple Choice

On the tree of life, the branch leading to animals is closer to fungi than it is to the branch leading to land plants. Which of the following statements is incorrect?

• Animals and land plants are more closely related to each other than either is to fungi.

• Animals and plants have a common ancestor.

• Fungi and animals have a common ancestor.

• Animals and fungi are more closely related to each other than animals are to land plants.

Multiple Choice

A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true?

• The amount of available food may have increased.

• The number of predators may have decreased.

• The squirrels of subsequent generations should show greater levels of genetic variation than previous generations because squirrels that would not have survived in the past will now survive.

• All of the above

Multiple Choice

During drought years in the Galapagos (an island Ecuador), small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection?

• Small birds gaining larger beaks by exercising their mouth parts

• More small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks.

• Small birds anticipating the long drought and eating more to gain weight and, consequently, growing larger beaks

• Larger birds eating less so smaller birds can survive

Multiple Choice

Claytonia virginica is a woodland spring herb with flowers that vary from white to pale pink to bright pink. Slugs prefer to eat pink-flowering over white-flowering plants (due to chemical differences between the two), and plants experiencing severe herbivory were more likely to die. The bees that pollinate this plant prefer also pink to white flowers, so that Claytonia with pink flowers have greater relative fruit set (reproductive success) than Claytonia with white flowers. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. If the researcher removes all slugs from the study population, what would you expect to happen to the distribution of flower colors in the population over time?

• The distribution of flower colors should not change.

• The percentage of white flowers should increase over time.

• The percentage of pink flowers should increase over time.

• The distribution of flower colors should randomly fluctuate over time

Multiple Choice

The following question refers to the evolutionary tree shown below:

The tree's horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V–Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species. Which of the five common ancestors, labeled V–Z, has given rise to the greatest number of species, both extant (still present, surviving species) and extinct (no longer existing)?

• V

• W

• X

• Z