S4.3.1 For the adult
Natural selection
Why do so many animals look just right for the place where they live?
What this chapter teaches
Natural selection has four steps: living things vary, more young are born than can live, those best suited survive and breed more, and they pass on their alleles. Over many generations the population changes. Antibiotic resistance is the same steps in bacteria.
Three questions to ask
There is no one right wording. Listen for the idea.
- Why does the antibiotic not cause the resistance?
- Why is a change made in one lifetime, such as strong arms, not passed on?
- Why should a person take the full course of an antibiotic as a health worker says?
After the chapter, the learner can
- Explain natural selection in steps: variation, competition, survival and inheritance
- Use natural selection to explain antibiotic resistance in bacteria
What they copy into their notebook
A population varies. More young are born than live. The best suited survive, breed and pass on alleles. Over generations the population changes. Resistant bacteria survive an antibiotic and divide.