4.7 - Investigating Diversity

Question 1

How can genetic diversity within or between species be measured?

Answer 1

By comparing:
1) The frequency of measurable or observable characteristics.
2) The base sequence of DNA.
3) The base sequence of mRNA.
4) The amino acid sequence of the proteins encoded by DNA and mRNA.

Question 2

What is interspecific variation?

Answer 2

This is variation between different species. It is due to different genes causing differences in physical traits, adaptations, habitats, etc. and environmental factors like climate, diet, lifestyle, etc.

Question 3

What is intraspecific variation?

Answer 3

This is variation between individuals within a species. It is due to different alleles (gene variants) and environmental factors.

Question 4

What are some limitations of using observable characteristics to investigate diversity?

Answer 4

• Traits are often polygenic - this means that they are influenced by several genes, which makes it challenging to separate the influence of individual genes
• Environmental factors can alter traits - this leads to variations that are not genetically based
• Traits may change gradually across a range - traits not falling into distinct categories make them difficult to differentiate

Question 5

How can DNA show genetic diversity?

Answer 5

Populations that are more genetically diverse will have more differences in their DNA sequences

Question 6

How can mRNA show genetic diversity?

Answer 6

Base sequences of mRNA are complementary to DNA so can assess genetic diversity

Question 7

How can amino acids show genetic diversity?

Answer 7

Populations that are more genetically diverse will have more differences in their amino acid sequences because they are determined by mRNA and DNA

Question 8

What does random sampling involve?

Answer 8

• Randomly generating coordinates across an area to prevent sampling bias
• Collecting samples from these random coordinates to represent the population
• Repeating this several times as a large sample size minimises the effects of chance
• Analysing the data collected to identify any relationships

Question 9

What is the mean?

Answer 9

The sum of the sampled values divided by the number of values

Question 10

What is the median?

Answer 10

The central or middle value of a set of values

Question 11

What is the mode?

Answer 11

The single value of a sample that occurs most often