[OLD] Taxonomy - DNA Technology Flashcards
3 ways to clarify evolutionary relationships
genome sequencing
comparing amino acid sequence
immunological comparisons
how can genome sequencing help clarify evolutionary relationships?
advances in genome sequencing have meant that the entire base sequence of an organisms DNA can be determined. The DNA base sequencing of one organism can then be compared to the DNA base sequencing of another organism to see how closely related they are. closely related species will have a higher percentage of similarity in their DNA base order.
how can comparing amino acid sequences help to clarify evolutionary relationships?
proteins are made from amino acids. the sequence of amino acids in a protein is coded for by the base sequence in DNA. related organisms have similar DNA sequences and so similar amino acid sequences in their proteins. The more similar the amino acid sequence of a protein, the more closely related the species are likely to be.
how can immunological comparisons help to clarify evolutionary relationships?
similar proteins will bind to the same antibodies.
e.g if antibodies to a human version of a protein are added p to isolated samples from some other species, any protein that’s like the human version will also be recognised by that antibody.
What is genetic diversity?
the number of different alleles in a population.
How did people used to measure genetic diversity?
by looking at the frequency of measurable or observable characteristics in a population e.h the number of different eye colours in a population and the number of people with each colour.
why was the frequency of measurable or observable characteristics in a population used to estimate genetic diversity?
different alleles determine different characteristics so a wide variety of each characteristic in a population indicates a high number of different alleles - and so a high genetic diversity
how are gene technologies now used to measure genetic diversity?
comparing DNA base sequences and comparing amino acid sequences
how does comparing DMA base sequences measure genetic diversity?
different alleles of the same gene will have slightly different DNA base sequences. comparing the DNA base sequences of the same gene in different organisms in a population allows scientists to find out how many alleles of that gene there are in that population.
how does comparing amino acids measure genetic diversity?
different alleles will produce slightly different mRNA base sequences, and may produce proteins with slightly different amino acid sequences
why do we now use gene technologies instead of observable characteristics to measure genetic diversity?
gene technologies can give a more accurately estimate of genetic diversity within a population or species. they also allow the genetic diversity of different species to be compared more easily.
