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10 Cards in this Set
- Front
- Back
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What is variation? |
It is the differences in the characteristics of individuals in a population |
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What causes variation? |
Inherited genes and the environmental conditions in which the organisms develop |
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What is a mutation? |
Changes to the sequence of bases in DNA which can lead to changes in the protein that a gene codes for |
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Mutations can lead to new phenotype if the new phenotype is suited to an environmental change- which can lead to a relatively rapid change in the species. True/ false |
True |
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Summaries the process of survival of the fittest and evolution in three steps: |
- individual organisms within a particular species may show a wide range of phenotype and genetic variation -individuals with characteristics most suited to the environment are almost likely to survive and breed successfully -The alleles that have enabled these and individuals to survive are them been passed on to the next generation |
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The theory of evolution by natural selection states: |
All species of living things have evolved from simple life forms that have first developed over 3 billion years ago |
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What are the 4 steps involved in selective breeding? |
- from existing stock so that the animals which have the most desirable characteristics -breed them with each other -select the best of the offspring and breed them together -continue this process over several generations so the desirable traits get stronger and stronger |
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What was the problems with selective breeding? |
Defects can occur in some animals due to lack of variation |
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What are the three basic steps to genetic engineering? |
- a useful gene is isolated from one organisms genome using enzymes and is inserted into a vector -The vector is usually a virus or bacterial plasmid -when the vector is introduced to the target organism the useful gene is inserted into it cells |
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What is a disadvantage and an advantage of genetically modified crops? |
Dis-Will affect the number of wild flowers, affecting the population of insects and reducing farm biodiversity Adv-increases the yield making more food |
