2314262
Description
Flashcards by Charlotte Hewson, updated more than 1 year ago
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Created by Charlotte Hewson
over 9 years ago
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| Question | Answer |
| what specifically makes organisms different? | proteins |
| what determines the variety of proteins? | DNA |
| what causes genetic diversity? | differences in DNA |
| what is an allele? | a variation of the same gene. |
| what is an example of what a gene then an allele may code for? | gene - iris allele - colour of iris |
| what is it about alleles that makes species (and their individuals) different from each other? | the combination of alleles |
| what does a greater number of different alleles lead to? | greater genetic diversity of that species |
| what does greater genetic diversity allow that species to do? | the species will be more likely to adapt to an environmental change |
| what are three factors that influence genetic diversity? | -selective breeding -the founder effect -genetic bottlenecks |
| what is another term for selective breeding? | artificial selection |
| what is selective breeding? | identifying individuals with desired characteristics and using them to parent the next gen. |
| what happens to offspring without desired characteristics? | killed or prevented from breeding |
| what does killing or preventing those with undesirable characteristics do? | alleles for unwanted characteristics are bred out of the population |
| what does this restricted variety of alleles lead to? | a population which only has the desired characteristics but leads to reduced genetic diversity |
| how does the founder effect occur? | when a few individuals from a population colonise a new region. |
| what feature does this new colony show? | less genetic diversity |
| when is the founder effect commonly seen? | when a volcanic island emerges and the few individuals that colonise it give rise to a new population that is genetically distinct from the populations left behind |
| what may happen to the new populations? | they could develop into a new species |
| what id less likely to happen to these new populations? | adapt to changing conditions due to reduced alleles |
| what is a genetic bottleneck? | a species may suffer as steep drop in numbers. the few survivors posses a smaller variety of alleles, reducing genetic diversity. as they breed, genetic diversity remains restricted. |
| what can cause a genetic bottleneck? | natural factors - volcanic eruption human factors - hunting |
| what is an example of a species that underwent this? | the northern elephant seal |
| what is an ethical issue with selective breeding? | -interferes with nature. -natural selection has been successful for millions of years. -do other species have rights? |
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