Question 1

Which of the following best explains why tuberculosis (TB) remains a significant health threat despite the availability of antibiotics?

Accepted Answer

Some strains of Mycobacterium tuberculosis have evolved resistance to antibiotics through natural selection.

Question 2

Which of the following is NOT one of Darwin’s four observations that led to the inference of natural selection?

Accepted Answer

Survival and reproduction are random.

Question 3

A population of bacteria is exposed to an antibiotic. After several generations, most bacteria are resistant to the drug. Which process best explains this outcome?

Accepted Answer

Natural selection

Question 4

Which of the following is an example of artificial selection?

Accepted Answer

The breeding of horses for racing

Question 5

Why does combination drug therapy (using multiple antibiotics at once) help prevent the evolution of drug-resistant bacteria?

Accepted Answer

It reduces the chance that a single bacterium will possess mutations conferring resistance to all drugs simultaneously.

Question 6

Which pattern of selection results in the population mean shifting toward one extreme phenotype over time?

Accepted Answer

Directional selection

Question 7

A flower species evolves brighter colors and increased nectar production. What is the most likely evolutionary advantage of these traits?

Accepted Answer

They attract more pollinators, increasing reproductive success.

Question 8

Which of the following statements about natural selection is correct?

Accepted Answer

Natural selection acts on individuals, but only populations evolve.

Question 9

Why is it important to complete the full course of antibiotics when treating a bacterial infection?

Accepted Answer

Stopping early allows surviving bacteria, possibly with resistance, to multiply.

Question 10

Which of the following best describes the concept of 'fitness' in evolutionary biology?

Accepted Answer

The ability of an organism to survive and reproduce relative to others in the population.

Question 11

A population of blue mussels develops thicker shells after the introduction of an invasive crab predator. Which pattern of selection does this illustrate?

Accepted Answer

Directional selection

Question 12

Which of the following is a common misunderstanding about natural selection?

Accepted Answer

Natural selection causes individuals to evolve during their lifetime.

Question 13

Which of the following best explains why natural selection does not produce 'perfectly adapted' organisms?

Accepted Answer

Environments change, and natural selection can only act on existing variation.

Question 14

Which of the following is an example of stabilizing selection?

Accepted Answer

Human birth weight, where both very low and very high weights have higher mortality.

Question 15

If a mutation arises in a bacterial population that confers resistance to an antibiotic, what must occur for this allele to increase in frequency in the population?

Accepted Answer

The mutation must be beneficial in the presence of the antibiotic, and resistant bacteria must survive and reproduce more than non-resistant bacteria.

Question 16

Which equation best represents the change in allele frequency due to natural selection in a population?

Accepted Answer

$$\Delta p = spq$$

Question 17

Why can’t humans rapidly evolve resistance to tuberculosis in the same way bacteria evolve resistance to antibiotics?

Accepted Answer

Most humans are never exposed to TB, and human generations are much longer than bacterial generations.

Question 18

Which of the following is an example of diversifying (disruptive) selection?

Accepted Answer

A population of birds where both very small and very large beaks are favored, but medium-sized beaks are selected against.

Question 19

Which of the following statements about mutations is correct?

Accepted Answer

Mutations are the ultimate source of new alleles in a population.

Question 20

Which of the following best describes evolution by natural selection?

Accepted Answer

A change in the traits of individuals in a population over generations due to differential survival and reproduction.

Chapter 12: An Evolving Enemy – Natural Selection and Tuberculosis

Study Guide - Practice Questions

Study Guide - Flashcards