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21 Cards in this Set
- Front
- Back
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Give the definition of a species.
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A group of organisms that can breed together to produce fertile offspring.
^^^^^ important to memorise |
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Animal and plant species can survive in many different environments this is because they have......
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Adapted to their environment.
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Adaptations make individuals more likely to survive and go on produce offspring, what is the result of this?
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This makes it more likely that the whole species will continue to exist in its environment.
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How is a cactus well adapted to hot dry conditions of the desert?
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1)rounded so small surface area compared to their volume to reduce water loss.
2) has thick waxy layer and leaves reduced to spikes to conserve water. 3) store water in stem to save for droughts 4) extensive shallow roots to Akers in lots of water quickly |
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How are fish adapted to water?
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1) fish have gills that filter oxygen from the water.
2)large tail fins to propell and smaller fins to guide 3) very streamline 4) fish have an organ called a swim bladder so they can adjust their depth without effort. |
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True or false. Individuals in a species have differences
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True. In a room of people you can see many differences eg hair colour eye colour. These differences are called variation.
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Some variation is genetic so it can be passed on through offspring give a cause of genetic variation.
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Genetic variation is when genes change. These are called mutations
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Give the causes of mutation.
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Can be caused by outside factors e.g radiation or chemicals and by mistakes when genes are copied during cell division
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What are the consequences of mutations in body cells?
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They usually have little or no effect, but could lead to cancer.
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What are the consequence of mutations in sex cells?
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Bigger effect as mutations are passed onto children. This can cause them to develop new characteristics. These might be harmfull e.g defects or help them to survive e.g wings
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Give a cliche definition of natural selection.
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Survival of the fittest.
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Under what process does natural selection cause evolution?
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1) living things show genetic variation.
2) limited resources means animal must compete. Only best survive. 3) some varieties are better adapted so Have better chance of surviving and passing on genes 4) this means a greater proportion of next generation are better equipped to survive 5) over generations, the species have become better and better. Best features naturally selected, species becomes more adapted. |
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Give an example of natural selection using short eared bunnies.
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Bunnies had short ears, did OK. Big eared bunny can hear fox coming better so hid. Short eared bunnies died. Now have lots of floppy eared bunnies.
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True or false. Organisms change (evolution wise) while they are alive and these changes are then passed on.
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False evolutionary changes are only made from generation to generation.
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Over generations the characteristic that increases survival becomes....
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More common within the population.
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What's selective breeding?
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It's where humans choose the characteristics they want in that animal and breed accordingly.
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True or false. Selective breeding always selects features that aid survival.
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False. Features like tasty may be selected instead.
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Give an example of selective breeding of cows for milk.
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The cow/s that produce the most milk will be breeder with bulls that make cows with lots of milk again and again until a hybrid species of milky cow is born.
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How long ago did life on earth begin?
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Around 3500 million years ago.
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True or false the first organisms were complex.
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False. They were very simple.
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All living thing evolved from what?
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Those very simple organisms that were the first organisms.
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