LE6 Flashcards
(13 cards)
What is a mutation?
a mutation is a random change to genetic material
What 3 things can mutations be classed as?
-neutral
-advantageous to survival
-disadvantageous to survival
Why are mutations so important?
mutations are important as they are the only source of new alleles
Give two examples of mutagenic agents:
-radiation (x-ray, u-v rays)
- some chemicals (bromine)
What can new alleles produced result in?
new alleles produced can result in plants and animals becoming better adapted to their environment
What is an adaptation?
an adaptation is an inherited characteristic that makes an organism well suited to survival in its environment
What happens to the best adapted individuals?
the best adapted individuals survive to reproduce, passing on favourable alleles; this is called “survival of the fittest”
What happens to individuals that are not well adapted?
individuals that are not well adapted die
What is natural selection?
natural selection is the survival of those best suited to their environment, this drives evolution
What is speciation?
speciation is the evolution of new species
When does speciation occur?
speciation occurs after part of a population becomes isolated by an isolation barrier
isolation barriers can be….
geographical, ecological or behavioural
Each sub-population evolves until…
each sub-population evolves until they become so genetically different that they are two different species and they can no longer interbreed
