10.4- INVESTIGATING DIVERSITY Flashcards
Traditionally, how was genetic diversity measured?
by observing the characteristics of organisms
What is the traditional method of measuring genetic diversity (by observing the characteristics of organisms) based on?
fact that each observable characteristic determined by gene(s)
Why does using observable characteristics to measure genetic diversity have its limitations?
as a large number of them coded for by more than one gene
What does a characteristic being coded for by more than one gene mean?
it’s polygenic
When a characteristic is polygenic, what does this mean?
they’re not discrete from one another but rather vary continuously
How else can characteristics be modified other than genes?
by environment
What has inferring DNA differences from observable characteristics been replaced by?
directly observing DNA sequences themselves
How is DNA sequencing done using computerised systems?
each nucleotide base tagged with different coloured fluorescent dye
produces series of coloured bands, each of which represents one of the four nucleotide bases
measure genetic diversity by sampling DNA of its members + sequencing it to produce pattern of coloured bands
What colour is each nucleotide base dyed in DNA sequencing?
adenine- green
thymine- red
cytosine- blue
guanine- yellow
What can DNA sequencing also be used for?
determine evolutionary relationships between species
How will the DNA be like when one species gives rise to another species during evolution?
DNA of new species will initially be very similar to that of species that gave rise to it
When one species gives rise to another species during evolution, how will the new species change?
due to mutations, sequences of nucleotide bases in DNA will change
What are the base sequence on mRNA complementary to?
to those of the strand of DNA from which they were made
As the base sequence on mRNA is complementary to those of the strand of DNA from which they were made, what does this mean?
we can measure DNA diversity, and so genetic diversity, by comparing base sequence of mRNA
What is the sequence of amino acids in proteins determined by?
mRNA, which in turn, is determined by DNA
