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Asexual reproduction
- - this is when all off spring have an exact copy of the parental DNA
- - bacteria and fission, strawberries reproducing with runners
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Sexual reproduction
- - In sexual reproduction the offspring inherit variation of characteristics
- - Each offspring has 2 copies of each gene, one gene form each parent
- - the offspring are never identical to the parents.
- - more variation within a population
- - genes are determined randomly
- - environment selects genes that are fittest for survival
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Mutations facts
- - they are caused by the environment or errors when DNA is replicated.
- - random mutations that occur
- - fundamentally important for the evolutionary processes
- - only process needed
- - only micro evolutionary process that creates new genes
- - if mutation helps organism survive, it is passed on while lethal are not passed on cuz they are dead
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Neutral Mutations
- - They do not have a positive or negative affect on the individual eg. birth marks
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Beneficial mutations
- - they are the most rare type
- - gives the individual an advantage
- - the individual is more likely to live , reproduce and pass the gene on
- Eg mutation allows humans to survive AIDS
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Harmful mutations
- - they are more common
- - results in a less likely to live, reproduce and pass the gene on.
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Mutation misconceptions
- - they are random do not occur when they are needed!!
- - mutations are a chance but evolution is not. This is because only the good mutations survive and then leads to natural selection .
- - Many babies with mutations do not live to reproduce
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Natural selection.
- - micro evolution process
- - some individual species have traits that make them survive and reproduce ( physical, physiological)
- - results in survival of the fittest
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Fitness def
- - this would be the odds of having an off spring
- - how well do your traits survive
- - a trait that is advantageous in one environment but not in the other .
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2 types of mutation
- - Somatic cell mutations - body cells undergo mutations and cannot be passed down
- - sex cells mutations - the reproductive cells undergo mutations and can be inherited
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What are the 4 main ideas of natural selection?
- - Over population
- - variation
- - natural selection
- -inherited
- - competition
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