Variation

Question 1

Genetic causes of variation

Answer 1

Mutations- sudden changes to genes and chromosomes may or may not be passed on to the next generation
Meiosis- mixes up DNA before it is passed into the gametes, therefore making them all different
Fusion of Gametes- a random process in which some characteristics are inherited form either parent

Question 2

Environmental influences of variation

Answer 2

Genes set limits while the environment determines where the organism lies within those limits. It is usually difficult to say a factor is purely down to the environment.

Question 3

Sampling bias

Answer 3

The selection process may be intentionally, or unintentionally biased. For example, avoiding muddy areas of a field in a plant sample. This can be avoided using a grid or transect and randomly generated numbers to determine where the sample will be taken.

Question 4

Minimising bias

Answer 4

Random numbers
Large sample size
Data analysis

Question 5

Interspecific variation

Answer 5

Between species eg/ cat and dog

Question 6

Intraspecific variation

Answer 6

Within a species eg/ terrier and collie

Question 7

Displaying genetic data

Answer 7

Discrete values, so use a bar chart for each type.

Question 8

Displaying environmental data

Answer 8

Continuous data, generally as a normal distribution curve

Question 9

Standard deviation facts

Answer 9

68% of data within +/- 1 σ

95% within +/- 2σ