Resistant organisms and antibiotic resistance

What is antibiotic resistance?

The ability of bacteria to survive and reproduce despite exposure to an antibiotic that would normally kill them or stop their growth.

How does antibiotic resistance develop through natural selection?

Random mutations produce variation; resistant bacteria survive antibiotic treatment and reproduce, passing on resistance alleles.

How do resistant bacteria become more common?

Antibiotics kill susceptible bacteria, while resistant bacteria survive and reproduce.

Why is antibiotic resistance evidence for Darwin's theory?

It shows that individuals with advantageous inherited characteristics survive and reproduce more successfully.

Do bacteria develop resistance because they need it?

No. Resistance may arise through random mutations or be acquired through gene transfer; antibiotics select for resistant bacteria.

How can resistant bacteria pass on resistance?

They pass resistance genes to their offspring and may also transfer genes to other bacteria.

Why does overusing antibiotics increase resistance?

It creates more selection pressure favouring resistant bacteria.

How can antibiotic resistance be reduced?

Use antibiotics only when appropriate, follow medical instructions and reduce the spread of infections through good hygiene.

What is a resistant strain of bacteria?

A group of bacteria that can survive an antibiotic that would normally kill susceptible bacteria or stop their growth.