10.4: Investigating Diversity Flashcards
What causes features of a species to change
Changes in DNA
What does comparisons of genetic diversity between and within a species enable scientists to do
Determine evolutionary relationships between them
What are the 4 ways in which comparisons can be made
- Comparison of observable characteristics
- Comparison of DNA base sequences
- Comparison of the base sequence of mRNA
- Comparison of amino acid sequences in proteins
What is the comparison of observable characteristics based on
That each observable characteristic is determined by a gene or genes (with environmental influences)
What causes variety of a characteristic
The variety of the alleles for that gene
Why is comparison of observable characteristics limited
- A large number of characteristics are coded for by more than one gene (polygenic)
- Characteristics can also be changed by environmental differences
How is the comparison of DNA base sequences carried out
By tagging each nucleotide base with different coloured fluorescent dyes
Genetic diversity can then be measured by comparing one species with another
What will the DNA of an organism that has given rise to another be like compared to the organism it has given rise to
The DNA sequence will initially be very similar to the OG species. However, due to mutations, the nucleotide base sequence will change and more differences will show.
What does more similarities in base sequence mean
That species are more closely related
How can comaprisons be made by mRNA base sequences
mRNA is coded for by DNA, therefore DNA diversity can be measured and therefore genetic diversity
How can comparisons be made by an amino acid sequence
Amino acid sequences are determined by mRNA which is in turn determined by DNA.
Similar amino acid = more closely related
