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Flashcards in Selection Pressure Deck (8)
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1

What happens to individuals that have advantageous characteristics?

Gain access to resources more quickly so reproduce more than those without. Advantageous alleles therefore shown more in the next generation.

2

What does ‘selected for’ mean?

When an allele that is advantageous is shown more in the next generation

3

What is a selection pressure?

An environmental factor that can alter the frequency of alleles in a population when it is limiting.

4

What is natural selection?

The increased chance of a survival and reproduction of organisms with phenotypes suited to their environment, enhancing the transfer of favourable alleles.

5

Give 4 examples of selection pressures.

- availability of nesting sites
- day length affecting reproductive behaviour
- overcrowded allows disease to spread (better immune system = passed on)
- predation

6

What individuals in the prey population are more likely to reproduce against the selection pressure of predation?

- better camouflaged
- mimic species who aren’t dangerous but mimic dangerous species
- those who survive best in certain temps
- those who resist habitat loss by humans

7

what does the term ‘fit’ describe?

How likely an organism is to survive, reproduce and pass on alleles to the next generation.

8

Why does the value of an allele depend on the environment?

The genotype that causes a phenotype stays fixed. It may be advantageous in one environment for some selection pressures but not others.