Booklet Flashcards
What are the two ways in which we compare DNA and proteins of different species?
Comparing the base sequence in DNA - DNA hybridisation
Comparing the sequence of amino acids in protein - immunological comparisons of antibodies and blood serum
What does comparing DNA and proteins of different species helps to determine…
The evolutionary relationship between them
Why does DNA hybridisation work?
DNA base sequences change over a period of time within species and are caused by mutations.
Over time a species will accumulate more and more differences in its DNA
Species that are more closely related should have more similarities in their base sequence than species that are more distantly related.
Why does comparisons of amino acid sequence in proteins work?
The sequence of amino acids is determined by the sequence of DNA bas sequences (codons)
Closely related species will have more similarities in their amino acid sequence of a particular protein than distantly related species
This can be done by simply measuring the number or similarities or differences in the sequence or by a different method
Human - 100% precipitation Chimpanzee - 95% precipitation Gorilla - 95% precipitation Orangutan - 85% precipitation Gibbon - 82% precipitation Lemur - 35% precipitation Which two primates does the immunological test show that are the most closely related?
Gorilla and chimp
Precipitation is the same
Human - 100% precipitation Chimpanzee - 95% precipitation Gorilla - 95% precipitation Orangutan - 85% precipitation Gibbon - 82% precipitation Lemur - 35% precipitation Which primate does the study suggest is the nearest relative of the orangutan? Why?
Gibbon
Closest with %precipitation
Why is courtship behaviour necessary?
To allow species to recognise members of the same species - to allow the generation of fertile offspring
To allow a member of a species to identify a mate that is capable of breeding
To form a pair bond which will lead to successful raising of offspring
To synchronise mating so that it takes place when there is a maximum probability of the gametes fusing
Some examples of behaviour in courtship behaviour
Aggression, intimidation, affection, grooming, territorial, attention seeking, team effort
Specific courtship behaviour of a mallard
Tail shake Bill shake Grunt whistle Head flick Nod swim Raise head or tail
How does adaptation increase survival of species?
Organisms adjust to suit the changing environment in which they live which occurs by the process of natural selection. This increases the reproductive success of species by helping its members survive long enough to breed. Responses to changing environment often occur by spontaneous mutation, which confers by chance an advantage on that organism in which the mutation has occurred.
Bacteria are able to add to genetic variation because they can exchange material by conjugation.
Inter specific
If one species differs from another species
Variation between species
Intraspecific
Variation within species
Genetic variation arises from
Mutations - sudden changes in genes and chromosomes may or may not be passed on to the next generation
Meiosis - nuclear division forms gametes, mixes up genetic material before its passed on to the gametes
Fusion of gametes - random, both parental and maternal so are genetically different from both, adds to variety of offspring
Asexual organism variation
Mutations
Genetic factors uses what sort of graph
Bar charts - without gaps
Environmental variation uses what sort of graph?
Polygenic variation
Normal distribution curve
Normal distribution curve
Mean measure of the maximum height of the curve
Standard deviation - measure of the curve -68% = one sd
Adenine and thymine pair together how many of what bonds?
2 hydrogen bonds
Cytosine and guanine pair together with how many of what bonds?
3 hydrogen bonds
How is DNA adapted to carry out its functions
Stable and can pass from generation to generation without change
Two separate strands that are joined together by h bonds which allows them to spartan during DNA replication and protein synthesis
Large molecule and so carries an immense amount f genetic information
Sugar phosphate backbone protect the bases from being corrupt from chemical and physical forces
What is a gene
Sections of DNA that contain the coded information for making polypeptides
Prokaryotes and their DNA
DNA molecules are smaller
Form a circle
Are not associated with proteins molecules
Therefore they do not have chromosomes
Eukaryotes and their DNA
DNA molecules are larger
Linear
Associated with proteins
To form structures called chromosomes
What is biodiversity
The range and variety of genes species and habitats within a particular region
