3.4.7 (investigating biodiversity)

Question 1

Ways of investigating biodiversity

Answer 1

Comparing:
-observable characteristics
-base sequence of DNA
-base sequence of RNA
-amino acid sequence

Question 2

Random sampling

Answer 2

Eliminates bias
Reduces effects of change by sampling large numbers
Minimises errors in obtaining measurements/samples

Question 3

Comparing characteristics

Answer 3

All coded for by DNA
Limitations:
-many characteristics are continuous/polygenic (controlled by more than one gene)
-environment can also influence characteristics

Question 4

Comparing DNA base sequence

Answer 4

DNA sequencing done by computers
Images scanned by lasers
More similar patten= more similar DNA= more closely related species
However evolution results in mutations causing differences in DNA

Question 5

Comparing mRNA base sequences

Answer 5

Coded for by DNA
Easier to access as in cytoplasm not nucleus
Limitations:
-doesn’t contain introns so may not give true picture
-may contain mutations

Question 6

Comparing proteins

Answer 6

Specific sequence of amino acids
Can compare this sequence to see how closely related species are
However different DNA sequences can produce same amino acid sequence as code is degenerate