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7.8 Continuing Evolution: revision map

The subtopic in the middle and four tasks round it: label a diagram, complete a table, put a process in order and fill 6 gaps. Every box rests on a learning objective of the topic in the AP Biology course and exam description. Type into the blanks and check them, or print it on A4, Letter or A3 with an answer key.

Unit 7 practice questions The whole Unit 7 map

Topic 7.8

Continuing Evolution

AP Biology · Unit 7 Natural SelectionName

7.8.AEvolution you can watch

Example	Selection pressure	Result
MRSA	antibiotics	resistant strains dominate in hospitals
Insect pests	insecticide	resistant insects survive and breed
	antiviral drugs, with a very high mutation rate	drug-resistant viruses, so patients take drugs in combination
Galapagos finches	drought, which leaves mostly hard seeds	average beak depth rose in a few generations

7.8.AHow resistance spreads

Number the steps in order.

Resistance alleles make up more of the population, and may spread to other bacteria by plasmids.
The resistant cells survive and divide.
An antibiotic is used and kills most susceptible cells.
A few bacteria carry a mutation that makes them resistant.

Topic 7.8Continuing Evolution

7.8.AEvolution of resistance

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7.8.ANever finished

Evolution does not stop: any population with variation facing selection pressure will change. mutate quickly and have short generation times, which is why a new flu vaccine is needed each year. Finishing a course of antibiotics, and not using them when they are not needed, slows the evolution of resistance, because it gives resistant cells fewer chances to be selected.

Word bank antibioticHIVresistant bacteriumresistant populationsusceptible bacteria killedViruses

Answer key

Every box on the sheet with its gaps filled in, as the subtopic reads in full.

LabelEvolution of resistance
1. resistant bacterium
2. antibiotic
3. susceptible bacteria killed
4. resistant population

TableEvolution you can watch

Example	Selection pressure	Result
MRSA	antibiotics	resistant strains dominate in hospitals
Insect pests	insecticide	resistant insects survive and breed
HIV	antiviral drugs, with a very high mutation rate	drug-resistant viruses, so patients take drugs in combination
Galapagos finches	drought, which leaves mostly hard seeds	average beak depth rose in a few generations

OrderHow resistance spreads
1. A few bacteria carry a mutation that makes them resistant.
2. An antibiotic is used and kills most susceptible cells.
3. The resistant cells survive and divide.
4. Resistance alleles make up more of the population, and may spread to other bacteria by plasmids.
GapsNever finished
Evolution does not stop: any population with variation facing selection pressure will change. Viruses mutate quickly and have short generation times, which is why a new flu vaccine is needed each year. Finishing a course of antibiotics, and not using them when they are not needed, slows the evolution of resistance, because it gives resistant cells fewer chances to be selected.