Variation and Genetic Diversity Flashcards
What is genetic diversity?
The number of different alleles in a species or population.
Why is genetic diversity important?
If the population has a low genetic diversity then it might not be able to adapt to a change in the environment and the whole population could die due to one event.
How does genetic diversity arise?
Mutations in the DNA to form new alleles. Different alleles are introduced into a population when individuals from other populations migrate into it and reproduce.
What is a giant bottleneck effect?
An event that causes a big reduction in the population. This reduces the number of alleles in the gene pool and that reduces genetic diversity. The survivors reproduce and the larger population is created from a few individuals.
What is the founder effect?
A few organisms from a population start a new colony and there are only a small amount of different alleles in the initial gene pool. This decreases genetic diversity and changes the frequencies of certain alleles. This could lead to an increase in genetic diseases.
What is variation?
The difference between individuals.
What is the difference between intraspecific and interspecific variation?
Intraspecific variation is variation between organisms of the same species and Interspecific variation is between organisms of different species.
What causes interspecific variation?
Different species have different genes.
What causes intraspecific variation?
Organisms of the same species have the same genes but different alleles. It can also be caused by differences in the environment.
What causes there to be a difference in alleles between organisms of the same species?
- Mutation in the DNA base sequence.
- Crossing over and Independent segregation in Meiosis.
- Sexual reproduction and random fertilisation.
When investigating variation why would you use a sample?
It would be too time-consuming and expensive to look at the whole population.
Why do we use random sampling?
It is random to make sure that there isn’t any bias. Also, it is to make sure that the sample is representative of the whole population.
Why must we analyze the data statistically?
To make sure that any variation observed isn’t due to chance.
How do you calculate the mean?
How do you calculate the standard deviation?
