Unit 3.5: Evolution of species Flashcards
Define mutation.
A random change of genetic matrial
What are mutations the only source of?
Alleles (form of genes)
Are mutations spontaneous?
Yes
Describe what variation in a population makes.
For a population to evolve over time in response to changing environmental conditions
Explain how mutations confer an advantage to an individual.
By making it better to survive
What is an adaptation?
Characteristics that make an organism well suited to survive in its environment or niche
Name 2 environmental factors that can increase the rate of mutation.
Radiation
Chemical
What is selection pressure?
Environmental factors that affect an organisms ability to survive in a certain environment
Give 2 examples of selection pressure.
Competition
Disease
Describe the process of natural selection.
The best adapted individuals survive to reproduce and pass on their favourable genes that give them the selective advantage.
What is passed onto offspring in natural selection?
Alleles
What happens to the animals that cannot compete as well as the other animals?
They die and don’t pass their genes
Define speciation.
The production of 2 or more separation species from a common ancestor.
What is the purpose of an isolation barrier?
To prevent them from exchanging genes with each other
Why does natural selection choose different mutations in each group?
For better survival in their environment
