Variation

Interspecific variation- variation between different species
Intraspecific variation- variation between the same species
1. Discontinous variation
  1. few distinct categories
  2. qualitative with no overlap between categories
  3. are controlled by one gene
  4. unaffected by the environment
2. Continuous variation
  1. no distinct categories
  2. controlled by a large number of genes
  3. quatitiative
  4. significantly affected by a large number of genes
3. Twin studies
  1. Identical twins have identical genes then differences between them are probably due to environment
Normal distribution curve
1. Mean- measurement at the maximum height of the curve
2. Standard deviation- the measure of the width of the curve
Random Sampling
1. To avoid bias. We can use random numbers generated from a computer to choose coordinates to place quadrats or traps to pick individuals
2. large sample size- reduces chance
  1. statistical tests to determine the extent chance has influenced the data
Causes of variation
1. mutation
2. meiosis
3. fusion of gametes
4. Environmental influences such as: soil conditions, pH, climatic conditions and food availability

Resource summary

	Created by Louise Tamin over 7 years ago