Investigating diversity

Question 1

Variation

Answer 1

Differences between individuals, within a species(intraspecific variation) or between different species (interspecific variation)

Question 2

What can variation be a result of

Answer 2

Genetic factors (diff alleles )
Environmental factors

Question 3

What is continuous variation

Answer 3

No distinct categories
Data tends to be quantitative
Controlled by many genes
Strongly influenced by the environment e.g. height

Question 4

What is discontinuous variation

Answer 4

Distinct, discrete categories
Data tends to be qualitative
Controlled by a single gene or a few genes
Unaffected by environment
e.g. blood group

Question 5

Genetic diversity

Answer 5

Number of different alleles in a population

Question 6

How can Genetic diversity be compared between species

Answer 6

Frequency of observable characteristics as different alleles determine different characteristics. So higher the variety of a characteristic, higher the variety of alleles of that gene and hence higher genetic diversity.

-Could also use base sequence of DNA and mRNA

-Amino acid sequence of the proteins encoded by DNA and mRNA

Question 7

Limitations of just looking at observable characteristics to compare genetic diversity

Answer 7

Many observable characteristics coded for by more than one gene so they vary continuously. So difficult to distinguish one from another.

Also characteristics could be modified by the environment so differences may be due to different environmental conditions rather than alleles

Question 8

Why do gene technologies give accurate estimates of genetic diversity

Answer 8

Different alleles of same gene have slightly different base sequences. You can compare the DNA base sequence of same gene in different organisms in a population to find out how many alleles of that gene are in the population

mRNA base sequences produce polypeptides with different amino acid sequence which can also be compared.