Natural Selection and Resistance Lesson

Open Ended

Why do we need new flu vaccines every year?

Multiple Choice

Natural selection acts on the phenotype of an organism, and eventually -

• the organism produces less offspring but more frequently.

• the alleles responsible for the new phenotype become more common in the population's gene pool.

• the organism's genotype changes as well.

• the variations move through the population and often reduce its overall fitness.

Multiple Choice

What is one way pesticide resistance can develop in a population?

• All individuals are equally resistant from the start.

• Pesticides mutate the DNA of every individual.

• Resistant individuals survive and reproduce.

• Non-resistant individuals develop immunity over time.

Multiple Choice

How does pesticide resistance illustrate the process of natural selection?

• It shows how all organisms become resistant eventually.

• It demonstrates survival of the fittest.

• It indicates that pesticides are ineffective.

• It proves that mutations are always harmful.

Open Ended

Back to the original question: Why do we need new flu vaccines every year?