Test Revision Flashcards
(18 cards)
Define natural selection
The process where an environmental factor acts on a population and results in some organisms having more offspring than others.
Examples of natural selection
The peppered moth, the colour of rats, pesticide resistance in insects
Define artificial selection
The process by which we choose to breed particular organisms with desirable features.
Examples of artificial selection
Breeding of cows of their meet/marbling, breeding of dogs
What is the importance of islands in speciation?
So then there is geographical isolation, then speciation can occur.
2 types of evidence for evolution
Fossils (the theropod) and anatomy
What is the significance of the ‘Archaeopteryx’?
It is a transitional fossil that shows the evolution of dinosaurs into birds and proved Darwin’s theory for evolution
What is a Homologous structure?
Structures in organisms that could be anatomically very similar but are used for very different purposes
How do scientists use Homologous structures?
Homologous structures are anatomical signs of evolution and show common ancestry
What are vestigial structures, with examples?
They are markers of evolutionary descent.
- Coccyx bones in humans
- Appendix in humans
- The ability to grow legs in snakes
What is geographical isolation?
a population that is separated from breeding with other organisms of the same species.
Examples of geographical isolation
Oceans, rivers, mountains, gorges
Why is variation important?
Variation must occur before speciation because natural selection is involved - selection can only occur when there is already variation in the population
What are the 5 steps of natural selection
V.I.S.T.A - Variation, inheritance, selection, time and adaptation
What is a species?
a group of organisms with similar characteristics that are capable of interbreeding and producing fertile offspring.
What are biotic and abiotic factors?
Biotic factors are living - predetation, disease, fewer offspring
Abiotic factors are non-living - temperature, sunlight, water, nutrients
What is antibiotic resistance?
When there is a mutation in bacteria that has allowed them to survive and reproduce.
What is insecticide resistance?
Resistance to chemical insecticides that were developed to kill insects, they soon had no effect as one of the insects mutated with resistance to the insecticide which soon got to the whole population
