Humans vs Bacteria
What type of organism is bacteria?
Single-celled organism
What do antibiotics kill?
Bacteria
What does variation mean?
Differences among individuals
What is lactase?
An enzyme that digests lactose
What is leptin
A hormone that helps regulate hunger
Name ONE way bacteria can be helpful to humans.
Digestion, making vitamins, breaking down waste
What happens to bacteria that survive antibiotic treatment?
They reproduce
Why is variation necessary for natural selection?
Some traits help survival (advantageous traits)
Why do some adults lose the ability to digest milk?
They stop producing lactase due to a mutation in genes
What does leptin normally signal to the brain?
That the body has enough energy- That the body is full
Why don’t antibiotics kill viruses?
Viruses are not living cells
Why does stopping antibiotics early increase resistance?
Resistant bacteria survive
What trait is being selected for when antibiotics are used?
Resistance
What is lactase persistence (tolerance)?
Ability to digest lactose as an adult
What is leptin resistance?
When the brain doesn't respond to leptin
Why can bacteria reproduce so quickly compared to humans?
They reproduce asexually and have short life cycles
How does antibiotic use act as a selective pressure?
Only resistant bacteria survive, the weak bacteria die off
Why does natural selection affect populations and not individuals?
Individuals don’t evolve
Why was lactase persistence an advantage in some human populations?
Extra nutrients/energy
Why might storing fat have been helpful for early humans?
Energy during food shortages
Explain why bacteria are able to adapt to changes in their environment faster than humans.
Short generations + large populations + variation
Predict how a bacterial population will change after many generations of antibiotic exposure.
Resistance to antibiotics increases over time
Compare how natural selection works in bacteria and humans.
Natural selection works the same in bacteria and humans because individuals have different traits and some traits help survival. Bacteria evolve faster because they reproduce quickly, while humans take many generations to change.
Explain how lactase persistence is evidence that humans are still evolving.
Trait frequency changed over generations in humans
Explain how leptin resistance could be connected to natural selection in past environments.
Traits that stored energy increased chances of survival