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(MUSIC). Have you noticed that you're different to your relations, parents, or carers,
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your next door neighbor,
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the kid who lives across the street,
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and everyone else on the planet?
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In fact, you're unique.
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But do you really know why you are different?
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Why are we all different to each other?
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Why does any organism have different characteristics to another organism?
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The answer lies in a long-running debate called nature versus nurture,
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or genetics versus environment,
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which is a little less catchy.
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Nature refers to our genetics.
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The unique combination of genes that we have naturally
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inherited from our biological parents from their DNA.
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Many characteristics are controlled by our genes,
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including our blood group,
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eye color, or natural hair color.
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Some diseases are also caused by our genes.
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For example, cystic fibrosis.
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The color of a flower or a fruit is controlled by genes in plants.
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Nurture refers to the effect of the environment on characteristics.
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The word literally means care.
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Examples of characteristics that are determined by the environment
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are weight or mass,
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which is dependent on your diet
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or the presence of a scar.
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Some diseases may be caused by environmental influences such as type 2 diabetes
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or coronary heart disease.
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Imagine a plant has not received enough sunlight or water,
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this may influence the height of the plant
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or the number of fruits produced.
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We would say that the environment has influenced these characteristics too
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or that a plant has been affected by nurture.
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Can you decide if each of these
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characteristics is controlled by inherited characteristics,
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the environment, or both?
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Where would each go on a Venn diagram?
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Pause the video while you think.
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Did you get them all right?
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The effect of genetics and the environment on
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characteristics has been researched using identical twins.
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Can you think why this is?
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Identical twins have identical DNA,
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so in theory, should have identical characteristics.
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It follows that any differences between a pair of identical twins
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could be due to the influence of the environment on their characteristics.
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In fact,
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twins often grow up to have very different
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personalities and preferences beyond their physical similarities.
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These studies showed that many characteristics are
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influenced by both genetics and the environment.
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Some studies actually used twins identical genomes as a control
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to prove the effect of the environment on the body.
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For example,
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one study showed how skin aged differently
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by comparing smoker twins with non-smoker twins.
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Remember that the characteristics of a living organism
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are influenced by its genetics and its interaction with the environment,
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so both nature
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and nurture are responsible.
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Please like and share our videos with your friends.
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If you have any questions that you want help with, just comment below.