4.7 Investigating diversity Flashcards
What are the ways to compare genetic diversity?
- Compare DNA base sequence
- Compare mRNA base sequence
- Compare amino-acid sequence of a protein
- Compare the frequency of measurable or observable characteristics (however less accurate)
Which are the best three ways to investigate diversity?
- Compare base sequence of DNA
- Compare base sequence of mRNA
-Compare amino-acid sequence of proteins
What method would you use to compare genetic diveristy within a species and why?
- Compare DNA base sequences
- To see minor variations
What method would you use to investigate diversity between species and why?
Amino-acid sequence of proteins
- To reduce noise
When comparing genetic diversity between species, what must be used to ensure comparison - give an example
- Genes/proteins must be present in all species of interest
- Respiratory proteins allow comparisons between kingdoms
- Haemoglobins would not
What can be said about how closely related two organisms are from their base sequence?
More differences in base sequence = more distantly related
What can be said about how closely related two organisms are from their amino-acid sequence?
- Less differences = closer related
- As similar DNA base sequences
When given numerical data for investigating diversity, what must always be reffered to?
Means and standard deviation
If there is no overlap between the standard deviations of the mean of A and B, what can be said?
There is likely to be a significant difference between A and B
If there is an overlap between the standard deviations of the mean of A and B, what can be said?
There is likely no significant difference between A and B
SD calculation
Immunological studies
look at extent of species- specific antibody binding to compl antigens
greater % binding = more closely related
What does gene technology allow us to do?
Read the base sequence of DNA and mRNA.
How do scientists compare evolutionary relationships between species?
By comparing how similar the base sequences are.
What does more similar DNA indicate?
A closer evolutionary relationship.
Why can mRNA be used to study relationships between species?
mRNA sequences are complementary to DNA, so they provide similar information about genetic similarity.
Why are observable characteristics useful in investigating diversity?
Because they are determined by DNA and proteins, showing similarities and differences.
Why are most observable features difficult to distinguish?
They are polygenic (coded by more than one gene) and tend to vary continuously.
Why might observable characteristics not be a true reflection of genetic differences?
Because they can be changed by environmental factors.
What determines the amino acid sequence of a protein?
mRNA, which is determined by DNA.
What does a similar amino acid sequence indicate?
That species are more closely related.
What are the two types of variation?
Inter-specific (between species) and intra-specific (within a species).
What statistical measures are used to analyze variation?
Mean and standard deviation.
What does a large standard deviation indicate?
Large variation within a dataset.
