Biology by Bradford
7.1.A, 7.1.BSelection in action
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7.1 Introduction to Natural Selection: 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 9 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.
Introduction to Natural Selection
AP Biology ยท Unit 7 Natural SelectionHover over a box to see it. Untick it to leave it off this sheet and its printout.
Name7.1.AHow a population changes
Number the steps in order.
- Over generations the proportion of the favored trait in the population rises.
- A population has heritable variation in a trait.
- The environment favors some variants, so they survive and reproduce more.
- The favored alleles pass to a larger share of the next generation.
Topic 7.1Introduction to Natural Selection
7.1.AThe conditions for natural selection
| Condition | In plain words |
|---|---|
| individuals in a population differ in their traits | |
| Inheritance | some of those differences are passed from parents to offspring |
| more offspring are born than the environment can support | |
| Differential survival and reproduction | those with advantageous traits leave more offspring |
7.1.BWords to be exact about
An individual with traits that suit its environment has higher , which is its reproductive success compared with others. A trait that raises it, such as camouflage, is an . Selection acts on individuals, but the thing that changes is the population: it is populations, and not individuals, that evolve. Selection can only work on variation that already exists, so it does not give organisms what they need.
Word bank adaptationdifferential survivalfitnessoffspringOverproductionpredatorsurvivorsvariationVariation
Answer key
Every box on the sheet with its gaps filled in, as the subtopic reads in full.
LabelSelection in action
- variation
- predator
- survivors
- differential survival
- offspring
TableThe conditions for natural selection
Condition In plain words Variation individuals in a population differ in their traits Inheritance some of those differences are passed from parents to offspring Overproduction more offspring are born than the environment can support Differential survival and reproduction those with advantageous traits leave more offspring OrderHow a population changes
- A population has heritable variation in a trait.
- The environment favors some variants, so they survive and reproduce more.
- The favored alleles pass to a larger share of the next generation.
- Over generations the proportion of the favored trait in the population rises.
GapsWords to be exact about
An individual with traits that suit its environment has higher fitness, which is its reproductive success compared with others. A trait that raises it, such as camouflage, is an adaptation. Selection acts on individuals, but the thing that changes is the population: it is populations, and not individuals, that evolve. Selection can only work on variation that already exists, so it does not give organisms what they need.