10.4 Investigating diversity

Question 1

Why is comparing genetic diversity important?

Answer 1

• it isn’t just observable characteristics which change.
• DNA controls the proteins made, and therefore changes with the organism
• comparing genetic diversity helps to determine the evolutionary relationship between species

Question 2

How did genetic diversity used to be measured?

Answer 2

• by looking at observable characteristics based on the fact they are based on genes
• the amount of variety within a characteristic depends on the number of alleles within the genes

Question 3

What are the negatives of the comparison of observable characteristics?

Answer 3

• many are coded for by more than one gene (polygenic)
• this means that they vary continuously and it can be difficult to distinguish between them
• characteristics are also the result of the environment

Question 4

How are DNA base sequences compared?

Answer 4

• we can now read the base sequences and determine the order of the neucleotides
• we can measure genetic diversity by sampling the DNA of members and sequencing it to produce a pattern of coloured bands
• we can view the change from one species to another as initially both are similar in DNA, then there is a mutation and species become different.

Question 5

Which bases correspond to which colours in base sequence comparison?

Answer 5

Adenine: green
Thymine: red
Cytosine: blue
Guanine: yellow

Question 6

How are mRNA base sequences compared?

Answer 6

As it is coded for by DNA it follows the previous method

Question 7

How are amino acid sequences in proteins compared?

Answer 7

• amino acid sequence is determined by mRNA and DNA

- similarities between AA sequences can show how closely related species are