Unit 3.2.1 - Variation within Species Flashcards
What does variation in a population mean??
The difference that exists between individuals
What are the two types of variation?
Interspecific
Intraspecific
What is interspecific variation?
Variation that exists between different species
What is intraspecific variation?
Variation that occurs within a species
If you wanted to measure variation would take a sample or a census?
A sample as a census would involve taking data from every member of a population which would take too long
Give two reasons why a sample has to be random?
- ) To avoid bias
2. ) So it can accurately represent the whole population
What three things can be used as a measure of variation within a population?
Range, mean, standard deviation
What is the mean?
The average value collected in the sample
What is the standard deviation?
How spread out the values collected are from the mean
What is the range?
The distance between the highest value and the lowest one
When can a normal distribution be used?
When the data is symmetrical about the mean
How are different standard deviations shown between two normal distributions?
The wider the bell curve the greater the standard deviation
What are the two types of intraspecific variation?
Discontinuous and continuous variation
What is discontinuous variation?
When the feature can be spilt into discrete groups
What is continuous variation?
The feature shows a whole range of values and not discrete groups
How is continuous variation controlled?
By a large number of genes
How is discontinuous variation controlled?
By a small number of genes
Similarities and differences between individuals in a species are caused by which two factors?
Genetic and environmental factors
What is meant by genetic factors in terms of variation?
Different combinations of alleles give different genotypes which mean different phenotypes show
What is meant by environmental factors in terms of variation?
When the appearance of phenotypes is affected by the environment
Is variation caused by just environmental or genetic factors?
No it can be a combination of both not just one
What is a genotype?
The organisms combination of alleles
What is a phenotype?
The organisms characteristic that shows
