Investigating diversity

Question 1

How can genetic diversity either within or between species be made?

Answer 1

By comparing:
The frequency of measureable or observable characteristics
The base sequence of DNA
The base sequence of mRNA
The amino acid sequence of the proteins coded for by DNA and mRNA

Question 2

Explain how the differences in a particular protein molecule (haemoglobin/cytochrome C/etc.) can provide evidence for phylogenetic relationships between organisms.

Answer 2

Mutations change base sequence; Causing change in amino acid sequence; causing change in the tertiary structure of proteins. Mutations build up over time; More mutations mean more differences in the base between distantly related species;
Fewer mutations in the base sequence in closely related species;
Closely related species have recent common ancestor and will have similar protein structure.

Question 3

How has gene technology caused a change in the methods of investigating genetic diversity?

Answer 3

Inferring DNA from measurable or observable characteristics has been replaced by direct investigation of DNA sequences.

Question 4

Explain the importance of random sampling.

Answer 4

To reduce bias

Question 5

How can you collect representative samples?

Answer 5

Take random samples; and large/many samples;

Question 6

Describe a method to take random samples.

Answer 6

Divide the study area into a grid; use a random number generator to give coordinates; take samples at the coordinates;

Question 7

How do you calculate a mean?

Answer 7

Add up all the values and divide by the number of values.

Question 8

What does the standard deviation tell you about the data?

Answer 8

The variation about the mean. If the standard deviation is large mean is less precise

Question 9

Explain what the data suggests if there is overlap between standard deviations.

Answer 9

If there is no overlap in 2 x standard deviations; Difference in mean is significant;
An overlap in 2 x standard deviations; Difference in mean is not significant;