Natural Selection and Adaptation

A comprehensive set of flashcards covering key concepts from Chapter 13 on Natural Selection and Adaptation, focusing on MRSA, antibiotic resistance, and evolutionary principles.

What does MRSA stand for?

Methicillin-Resistant Staphylococcus aureus

Why is MRSA difficult to treat?

It has developed resistance to most antibiotic drugs.

How many people were killed by MRSA in the US in 2012?

10,000 people.

What is Staphylococcus aureus commonly known as?

Staph.

What percentage of the US population carries S. aureus?

Approximately 33%.

What percentage of the US population has MRSA strains?

Approximately 2%.

How is MRSA transmitted?

By direct or indirect contact.

Why do athletes have an increased risk of MRSA?

Due to contact with skin, items, or surfaces that harbor MRSA.

What do antibiotics interfere with in bacteria?

The function of essential bacterial cell structures.

What type of antibiotics work by interfering with synthesize cell walls?

Beta-lactams.

How do bacteria reproduce?

By binary fission.

What does binary fission produce?

Two daughter cells from one parental cell.

What can random mutations in bacteria lead to?

Resistance to antibiotics.

What can gene transfer do in bacteria?

Spread alleles for antibiotic resistance to other bacteria.

What is a population in biological terms?

A group of organisms of the same species living together in the same geographic area.

What can cause a population to evolve?

Changes in allele frequencies when some traits are favored over others.

What does the term 'fitness' describe in an evolutionary sense?

The relative ability of an organism to reproduce in a particular environment.

What increases the likelihood of alleles being passed to the next generation?

Higher fitness.

What determines the success of a specific phenotype?

The environment.

What is natural selection?

Differential survival and reproduction of individuals within a population in response to environmental pressures.

What happens to advantageous traits over time?

They become more common in a population.

Which process leads to changes in allele frequencies over time?

Evolution.

What is directional selection?

A pattern where the predominant phenotype shifts in a particular direction.

What happens during stabilizing selection?

The phenotype of the population settles near the middle of the range.

What is diversifying selection?

A pattern where extreme phenotypes are favored over intermediate phenotypes.

How do antibiotics affect bacterial populations?

They create an environment that favors resistant bacteria.

What does Ruth Lynfield emphasize about antibiotic usage?

That careful use of antibiotics is crucial as it drives antibiotic resistance.

What is one method to prevent antibiotic resistance in livestock?

Reduce antibiotics in livestock feed.

How can hand washing help prevent infections?

It can reduce the spread of bacterial infections.

What is the purpose of disinfecting common surfaces?

To reduce transmission of infection by contact.

Why should antibiotics not be taken for viral infections?

Viruses are not affected by antibiotics.

What outcome can occur from the overuse of antibiotics?

It can cause resistant bacterial strains to become widespread.

What is a factor that can change allele frequency over time?

Environmental pressures favoring certain traits.

What is the role of phenotypes in evolution?

Successful phenotypes become more common due to fitness in their environment.

What does it mean if a phenotype has low fitness?

It reproduces poorly compared to others.

How do antibiotics create strong directional selection for resistance?

By providing a survival advantage for resistant genes.

How do successful reproductive strategies affect a population?

They establish changes in genotype frequencies.

What are some strategies to combat antibiotic-resistant bacteria?

Washing hands, keeping environments clean, and researching vaccines.

What defines a genetically diverse population?

It has varying allele frequencies among its members.

What is the consequence of environmental changes on bacterial fitness?

Bacteria with resistance genes have highest fitness in the presence of antibiotics.

What describes the interaction between phenotype and environment?

It determines an organism's fitness.

What type of selection favors extreme phenotypes in diverse populations?

Diversifying selection.

What do we call the survival and reproduction that depends on interaction with the environment?

Natural selection.

What can protect athletes from MRSA?

Keeping locker rooms and sports equipment clean.