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level: Evolution of Species

Questions and Answers List

level questions: Evolution of Species

QuestionAnswer
What is a MutationA random and permanent change to the DNA of an organism
What are 2 mutagenic agentsRadiation - x-rays and UV lights Chemicals - mustard gas and caffeine
Why is variation importantTo allow the population to evolve over time in response to changing environmental conditions
What are AdaptationsThey increase their chances of survival and reproduction
What are the 3 AdaptationsStructural - what the organism looks like Physiological - how the organism works Behavioural - what the organism does
What is Natural selectionWhen species produce more offspring than the environment can handle. It occurs when there are selection pressures (survival of the fittest)
What is the result in Natural selectionThe best adapted individuals survive to reproduce and pass on the best allele that give them a selective advantage
What are the 4 stages of Natural Selection1 - There is variation in the population 2 - The environment cannot support an unlimited population, so the individuals who are less well adapted die and do not reproduce 3 - The best adapted individuals reproduce producing individuals with similar genetic traits 4 - The most advantageous traits become more common in the population
what are the 3 reasons why the population become isolatedGeographic - sea, river, mountain, desert Behavioural - different breeding time, different mating display Ecological - areas have different temperatures, water availability, pH
What are the 4 stages of Speciation1 - Isolation - Geographic, Behavioural, Ecological 2 - Mutations - occur in both populations, mutations are needed to create new alleles in each of the populations 3 - Natural Selection - Occurs whenever a mutation gives members of the subpopulation a selective advantage 4 - Over Time - The gene pool of each population changes. The 2 populations are 2 different species
What is a SpeciesA group of organisms that are so similar they can interbreed to produce fertile offspring