The Phenomenon (Addie’s Case)
Why was Addie’s illness confusing?
She got better, then sick again instead of fully recovering.
What type of organism are bacteria?
Single-celled organisms.
How do bacteria reproduce?
By binary fission (splitting into two cells).
What is natural selection?
The process where organisms with helpful traits survive and reproduce more.
What is antibiotic resistance?
Bacteria survive antibiotics
What pattern did Addie’s illness follow over time?
She improved, then relapsed, and became more sick.
Where are bacteria commonly found?
Almost everywhere, including surfaces, air, and our bodies.
What happens to a bacterial population over time without antibiotics?
It grows quickly (exponential growth).
What is the main difference between Lamarck and Darwin?
Lamarck said traits develop from need; Darwin said traits already exist and are selected.
What happens to bacteria when antibiotics are used?
Susceptible bacteria die, resistant ones survive.
What question did Addie’s case lead us to investigate?
Why don’t antibiotics work like they used to?
How do bacteria spread?
Through contact with people, surfaces, or shared objects.
What does it mean that bacteria have variation?
They have different traits within the population.
Why is Lamarck’s explanation incorrect for antibiotic resistance?
Bacteria do not develop resistance because they need to.
Why do resistant bacteria become more common over time?
They survive and reproduce more than others.
What evidence showed the antibiotics were not fully working?
The infection came back after treatment.
Why are some bacteria harmful while others are not?
Some cause infections, while others are harmless or helpful.
Why does rapid reproduction matter for resistance?
Resistant bacteria can multiply quickly and become more common.
How does natural selection explain resistant bacteria?
Resistant bacteria survive antibiotics and reproduce.
How do human behaviors increase antibiotic resistance?
Overusing antibiotics, not finishing prescriptions, poor hygiene.
How does Addie’s case connect to antibiotic resistance?
Some bacteria survived treatment and multiplied, making the infection harder to treat.
What did the petri dish investigation show about bacteria?
Different locations have different amounts and types of bacteria.
What did the simulations show about populations over time?
Population size increases, and trait proportions can change, becoming more resistant over time, even when individual bacteria do not change.
What evidence supports Darwin’s explanation over Lamarck’s?
Resistant bacteria existed before antibiotics and were selected, not in response to antibiotics.
Why is antibiotic resistance a major public health problem?
Infections become harder to treat and can spread widely.