Bio - Evolution

Which of the following processes causes the appearance of new variants in a population?

Mutation

Which of the following is a correct statement of the relationship between fitness and natural selection?

Natural selection favors variants with higher relative fitness within a population.

In the video, what does the UK's Chief Medical Officer suggest for promoting the development of new antibiotics?

Encouraging big pharmaceutical companies to start investing again in new drug research and development

Mutations provide the basis for genetic diversity in a population. What is the effect of combination drug therapy on new bacterial mutations?

New mutations decline because few bacteria survive exposure to multiple drugs.

Should patients with Mycobacterium tuberculosis infection stop taking antibiotics as soon as the symptoms of cough and fever stop? Why or why not?

No, because some variants of M. tuberculosis survive antibiotic treatment and proliferate, causing drug-resistant TB.

In the projected video showing the growth of bacteria, why did the bacteria grow up to the edge of the area with antibiotics, pause, then continue to grow across the area with antibiotics?

A few bacteria experienced random mutations in their DNA, which allowed some of them to grow even though antibiotics were present.

Approximately how many people worldwide die of tuberculosis (TB) each year? Why is the number of cases increasing after a long period of decreasing?

2 million; rise of multidrug-resistant TB (MDR-TB)

Andrew Speaker, a lawyer from Atlanta, made headlines when he traveled on an airplane despite having been told that he had extensively drug-resistant tuberculosis (XDR-TB). Mr. Speaker did not have symptoms of TB. Many people were outraged at his "reckless" behavior that exposed other people to TB. Which of the following suggests that their outrage was misplaced?

TB is almost never transmitted by people without symptoms.

Which of the following is not a contribution to the current high prevalence of drug-resistant infectious diseases such as tuberculosis?

Taking multiple antibiotics at the same time

What is the concern about using antibacterial and antimicrobial soaps?

The use of any chemical that kills bacteria can eventually lead to resistance to that chemical in the population of bacteria.

Which of the following contributes the LEAST to the problem of antibiotic resistance?

taking the entire course of antibiotics as prescribed by the doctor

Hominin

A human or human ancestor

Darwin stated four conditions that are necessary for natural selection to occur. Which of these conditions is not fulfilled by Mycobacterium tuberculosis, the organism that causes tuberculosis?

All of Darwin's conditions are fulfilled.

Which of the following correctly describes what the video referred to as a "microbial cure"?

Antibiotics are used to kill all of the infectious bacteria in a person

Over time, bacteria have become increasingly resistant to antibiotics. Which of the following best explains this in terms of natural selection?

Bacteria that happen to have natural resistance to antibiotics survived and reproduced.

Brittany has a small, painful sore just under her nose. Her doctor prescribed methicillin, an antibiotic, which Brittany took, but the sore only got worse. Brittany says, "No big deal, it'll go away." But her best friend, who is taking this Biology course, tells her, "You'd better go to the doctor. You could get very ill and even die from this." What does Brittany's friend fear?

Brittany is infected with methicillin-resistant Staphylococcus aureus (MRSA).

Microevolution

Changes that occur in the characteristics of a population as a result of natural selection

What is the principle behind the use of combination drug therapy in treating certain infectious diseases?

Different drugs target different portions of the bacterial genome, making the likelihood of resistance to all the drugs very low.

The fossil record shows that horses steadily increased in size over a period of about 51 million years. This represents which of the following?

Directional selection

Natural selection acts on variations that result from what?

Genetic mutations

An Atlanta refrigerator company called CoolIt noticed that sales were falling until market research found that customers preferred pink refrigerators... CoolIt's president told investors "It's natural selection; we adapted and evolved." Is his statement a correct use of the concept of evolution; why or why not?

Incorrect; evolution occurs only through natural selection of traits that are already present in the population, but pink fridges were invented as a "new" adaptation.

Darwin noted that populations produce more offspring than will survive. Why is this fact a central component of the theory of natural selection?

Larger population will have more variants with different fitness levels subject to natural selection.

What is one characteristic of multidrug-resistant TB (MDR-TB) that limits its ability to infect people on a massive scale?

MDR-TB is much less likely to spread to other people than nondrug-resistant TB.

A particular antibiotic kills 99% of a bacterial population. What will be the result of the continued application of this antibiotic?

Over time, the antibiotic will become less effective at killing the bacteria.

People with tuberculosis develop tubercles in the lungs. What are the positive and negative effects of tubercles?

Positive: slow the spread of disease; negative: permanently damage the lung.

One of Darwin's key observations was that individuals within populations are different from each other. You observe three dogs, Brownie, Blackie, and Peachy, at play. What is the term for different colors of the dogs?

Variant

Macroevolution

The diversification of life that results from the emergence of new species from ancestral species.

The bipedal gait of humans and the Panda's thumb are examples of which of the following?

The limitations of adaptations

Alcohol is toxic to most fruit flies, but fruit flies that metabolize alcohol quickly survive alcohol exposure better than normal metabolizers. Assume that about 10% of the fruit flies in a normal laboratory population consists of these fast alcohol-metabolizing flies. Now you expose all of the fruit flies to alcohol and let them interbreed. After many generations, what will occur?

The proportion of fast-alcohol-metabolizing flies will increase.

In which situation can just a few genes dramatically change an organism's entire appearance?

When the genes each control the expression of many other genes