Question 1

What is gene transfer?

Accepted Answer

The answer of What is gene transfer?
...

Question 2

If a man fathers a child at 20 years of age,the DNA that was passed on to the child was created 20 years after the zygote that created the man.How many generations of bacteria could be formed in that same 20 years (ignore leap years)? How many more chances of mutation would the bacterial DNA have?

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The answer of If a man fathers a child at...

Question 3

A population is described as

Accepted Answer

A population refers to a group of individuals of the same species living in the same geographic area and able to interbreed. Therefore, choice D, which states "all the members of the same species living in the same area," is the best choice.

Question 4

Do you think drug resistance is more likely to develop in a species of bacteria that can double its population every 20 minutes or a species that doubles its population every 24 hours? Explain your answer.

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Question 5

Five different strains of bacterial cultures were grown overnight in a medium containing antibiotics.Of the resulting population densities listed below,which was the most fit?

Accepted Answer

The most fit strain is the one with the highest population density, which in this case is 7.5 x 10^17 cells/ml (Choice C). This indicates that this strain was able to survive and reproduce better than the other strains in the presence of the antibiotics.

Question 6

A highly resistant antibiotic strain of S.aureus would reproduce best in

Accepted Answer

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Question 7

Drug-resistant populations of bacterial stains are a result of

Accepted Answer

Drug-resistant populations of bacterial stains are a result of drugs or other selective environmental pressures. These can include overuse or misuse of antibiotics, which leads to the survival and proliferation of bacteria that have developed resistance to the drugs. This selective pressure drives the evolution of drug-resistant strains.

Question 8

Bacterial cell division is known as

Accepted Answer

Bacterial cell division is a process called fission, in which a single cell divides into two identical daughter cells.

Question 9

Your friend has contracted a bacterial infection.Which of the following hypothetical drugs would you suggest as the best way to prevent an antibiotic-resistant allele from arising and spreading throughout the bacterial population in her body?

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The answer of Your friend has contracted a bacterial infection.Which...

Question 10

Drug resistance may take which of the following forms?

Accepted Answer

Drug resistance can take many forms, including the production of enzymes such as ß-lactamases that can break down certain antibiotics, the production of proteins that can disable antibiotics, and the production of altered protein shapes that antibiotics can no longer bind to. Therefore, all three options (A, B, and C) are correct.

Question 11

A bacterial strain will most likely become antibiotic resistant when it is grown in

Accepted Answer

MRSA (Methicillin-resistant Staphylococcus aureus) is a type of bacteria that is already resistant to many antibiotics. If a bacterial strain is grown in the presence of MRSA, it may acquire resistance genes through horizontal gene transfer, increasing the likelihood of becoming antibiotic resistant.

Question 12

Assume that every time you copy DNA,whether it is bacterial DNA or human DNA,you have the same rate of mutation.If that is the case,explain why bacteria mutate to adapt to their environment much faster than humans.

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Question 13

A bacterium has a gene that creates a ß-lactamase enzyme.It passed that gene to another bacterium it encounters.What is the result of that gene transfer?

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Question 14

Which bacterial phenotype would have the highest fitness if it were cultured in a medium containing antibiotics?

Accepted Answer

In a medium containing antibiotics, the bacterial phenotype with the highest fitness would be the highly antibiotic-resistant variant as it would be able to survive and replicate better than the other phenotypes in the presence of antibiotics. The antibiotic-resistant variant with moderate resistance may survive to some extent, but it may not be able to perform as well as the highly resistant variant. The slightly antibiotic-resistant variant may not show much difference in fitness compared to the antibiotic-sensitive variant, as both of them may not be able to survive well in the presence of antibiotics.

Question 15

Which of the following factors will NOT influence the rate at which drug resistance can evolve in a population of bacteria?

Accepted Answer

The age of the host is not a factor that directly influences the rate at which drug resistance can evolve in bacteria. Factors A, B, C, and D can all affect the frequency of genetic mutations and swapping, which can allow for the evolution and spread of drug resistance in bacterial populations.

Question 16

What are the two mechanisms by which a bacterial cell can become resistant to antibiotics?

Accepted Answer

The answer of What are the two mechanisms by which...

Question 17

Overprescription of antibiotics and their improper use is a cause of

Accepted Answer

Overprescription and improper use of antibiotics can lead to a rise in drug-resistant bacterial populations. This is because when antibiotics are used excessively, bacteria can develop resistance to the drugs, making them less effective in treating infections. This can lead to the development of more drug-resistant species.

Question 18

What is responsible for genetic variation in bacteria?

Accepted Answer

All of the above are responsible for genetic variation in bacteria. Mutations can occur during binary fission, gene influx can occur from different bacterial strains, DNA influx can occur from the environment, and gene transfer can occur from the same bacterial species through mechanisms such as conjugation, transformation, and transduction. These processes contribute to the genetic diversity of bacterial populations.

Question 19

All the individuals of a species living in a specific area compose a

Accepted Answer

A population is defined as all the individuals of a species living in a specific area. A colony refers to a group of organisms of the same species living closely together, while a species refers to a group of organisms that are capable of interbreeding and producing fertile offspring. A community refers to all the different species living in a specific area, and a clade refers to a group of organisms with a common ancestor.

Question 20

How would the resistance level of an antibiotic-sensitive variant in culture medium containing a minimal amount of antibiotics change over time?

Accepted Answer

In culture medium with a minimal amount of antibiotics, there is no selective pressure for antibiotic resistance to develop or be maintained. Therefore, the resistance level of an antibiotic-sensitive variant would remain low over time.

Quiz 14: Natural Selection and Adaptation Bugs That Resist Drugs