GENETICS AND EVOLUTION
INHERITANCE AND VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Length of index finger
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Eye colour
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Height
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Foot size
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Detailed explanation-1: -E.g. male or female, green/brown/blue eyes. This is known as discontinuous variation.
Detailed explanation-2: -Discrete variation is either/or and is often caused by the presence or absence of a small number if genes. For example, our ability to “roll” our tongues is determined by just one gene. We can all either roll our tongue or not-there’s nothing in between.
Detailed explanation-3: -As with many traits, the nature of human eye colour variation is continuous, spanning from the lightest shades of grey or blue to the darkest shades of brown or black4.
Detailed explanation-4: -Eye color is neither continuous nor discontinuous variation. It is a discrete variation. Eye color involves many genes (polygenic) hereditary trait. It cannot be changed and only has a finite amount of variance, so it can’t be continuous.
Detailed explanation-5: -So, the correct answer is ‘Mutations’