Variations, Mutations, and Selection (Leaving Cert Biology): Flashcards
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Variation
Variation
Differences between members of same species
Acquired variations
Acquired variations
Traits developed during lifetime, not inherited
Are acquired variations inherited?
Are acquired variations inherited?
No, not genetically controlled
Example: acquired variation
Example: acquired variation
Learning to walk, speak, ride bike, scars
Inherited variations
Inherited variations
Genetically controlled traits passed from parents
Example: inherited variation
Example: inherited variation
Blood groups, eye colour, hair colour, earlobe type
Two causes of inherited variations
Two causes of inherited variations
Sexual reproduction and mutations
Mutation
Mutation
Spontaneous change in genes or chromosome structure
Three effects of mutations
Three effects of mutations
Harmful, neutral, beneficial
Gene/point mutation
Gene/point mutation
Change in single gene affecting few DNA bases
Chromosomal mutation
Chromosomal mutation
Large-scale change to chromosome structure/number
Artificial selection
Artificial selection
Humans breed organisms with desirable traits
Example: artificial selection
Example: artificial selection
Breeding cattle for milk, crops for yield, dogs for traits
Natural selection
Natural selection
Organisms with advantageous traits survive & reproduce more
Peppered moths: pre-pollution
Peppered moths: pre-pollution
Light moths camouflaged on pale bark, survived better