Aqa As Biology Unit 2

Front 1

1. What is the difference between interspecific variation and intraspecific variation?

2. How is variation measured?

Back 1

1. Interspecific variation is the differences between species and intraspecific variation is the differences between individuals within the same species.

2. Sampling.

Front 2

Describe two problems with sampling and suggest how they can be overcome.

Back 2

1. Sampling bias: investigators knowingly or not choose individuals that are not representative of the population as a whole. Can be overcome by using random sampling.
2. Chance: individuals chosen are not representative of the whole population.
Both can be overcome by using a large sample size and analysing the data using statistical tests.

Front 3

1. What are the 3 causes of genetic variation?


2. What other factor affects variation?

Back 3

1. Mutations; meiosis (both independent segregation and crossing over generate new combinations of alleles); and fusion of gametes.
2. The environment.

Front 4

1. What type of variation is blood group an example of?
2. Is it controlled by one or many genes?
3. Does the environment affect this type of variation?

Back 4

1. Discontinuous variation or genetic variation.
2. It is controlled by one or two genes.
3. The environment has no effect on this type of variation.

Front 5

1. What type of variation is height an example of?
2. Is it controlled by one or many genes?
3. Does the environment affect this type of variation?
4. What shape would it make if it was graphed?

Back 5

1. Continuous or environmental variation.
2. Many genes control these type of characteristics.
3. The environment has a large effect on this type of variation.
4. It would produce a normal distribution curve.

Front 6

1. What is the mean?
2. What is standard deviation?
3. Which is more useful and why?

Back 6

1. This is the average: all of the values added together and divided by the number of values there are.
2. This is a measure of the range of values around the mean or how spread out they are.
3. Standard deviation is more useful because it shows you how much variation there is in a sample.