Biology Sac yr 12: Evolution
Terms in this set (27)
What is allopatric speciation?
List and explain the steps.
Formation of a new species due to a geograpthical barrier that leads to reproductive isolation.
What is meant by biological fitness?
Describe the difference between homologous and analgous structures.
Examples of homologous and analgous structures.
What information can you get from a phylogenic tree?
What is a point mutation?
where a single nucleotide within the original DNA sequence is affected.
What are the different type of point mutations and the effects they have?
Silent mutation (synonymous):
No impact as the codon still codes for the same amino acid and hence the same protein.
When the codon codes for a different amino acid and this can change the protein.
When the change leads to a STOP codon and the protein prematurely ends being translated.
What is the bottleneck effect?
Occurs when a large population is dramatically reduced in size, thereby reducing its genetic diversity.
How does the bottleneck effect affect allele frequencies?
The frequency of some alleles in the population may therefore be reduced or eliminated altogether
Define the term gene pool.
How can DNA hybridzation technique be used to determine the relateness of different species?
What is mitochondrial DNA?
How can mitochondrial DNA be useful to evoluntionary studies?
What are the absolute dating techniques?
Age for absolute dating vs age for relative dating
Conditions that increase genetic variation
Conditions that decrease genetic variation
When is genetic variation an advantage?
When is genetic variation an disadvantage?
List anatomical characteristics specific to humans
List cultural characteristics specific to humans
How to analyse data
- Changes to DNA.
- Can be induced by physical or chemical mutagens e.g radiation.
Benefitical effect of mutations of survival
New alleles can arise due to mutations.
Those mutations increase the chance of survival of the organism such as having 2 colour variations of the peppered moth.
In general more variation is beneficial for the survival of the species in changing environmental conditions.
Deleterious effect pf mutations on survival
Disrupt the function of the protein so organism is unable to carry out basic processes eg. Cystic fibrosis.
Neutral effect of mutations on survival
When amino acid is unchanged or changed to one with similar properties which have no effect on function of changed protein
Selection pressure leads to competition for survival
Favourable characteristic more likely to survive and reproduce
Overtime more (or all) individuals with favourable characteristic