Variation 2.1

Question 1

What is intraspecific variation?

Answer 1

The differences that occur within a species. (E.g length of a giraffe neck).

Question 2

What causes intraspecific variation?

Answer 2

Genetic and environmental factors

Question 3

What is continuous variation?

Answer 3

For any species a characteristic that changes gradually over a range of values shows continuous variation. Examples of such characteristics are height, weight, foot length.

Question 4

What is discontinuous variation?

Answer 4

A characteristic of any species with only a limited number of possible values shows discontinuous variation. Here are some examples: gender (male or female), blood group (A, B, AB or O), eye colour.

Question 5

Explain why over eating is caused by environmental and genetic factors.

Answer 5

Environmental: availability of food
Genetics: food consumption increases brain dopamine levels, once enough dopamine was released people would stop eating. However it was discovered that some people had one allele that had 30% fewer dopamine receptors so people over eat.

Question 6

What is interspecific variation?

Answer 6

Variation that exists between different species.

Question 7

The sample, when studying variation has to be random, why?

Answer 7

To make sure the sample isn’t biased
To ensure any variation isn’t just due to chance, it’s important to analyse the results statistically, which creates more reliable results.

Question 8

What is standard deviation?

Answer 8

The variation of values from the mean.