Genetic Diversity Flashcards
(14 cards)
Define genetic diversity
The number of different alleles of genes in a population
Give the 4 things that causes genetic diversity to occur
- Mutation- this produces new alleles
- Independent segregation of homologous chromosome pairs on the equator during meiosis
- crossing over the tips of non sister chromatids during meiosis
- random fusion of haploid gametes to produce a diploid zygote
Define gene pool
All the alleles of genes present in a population
Define alleles
Different versions of a gene
Define discontinuous variation
Variation that’s in distinct categories. This tends to be qualitative, is controlled by few genes and isn’t affected by the environment.
Define continuous variation
Variation with no distinct categories, which tends to be quantitative. Controlled by many genes and affected by the environment.
What type of graphs are used for discontinuous data
Bar charts
What type of graphs are used for continuous data
Histograms
Explain why samples must be random and large
Random - to remove bias
Large - enough data to represent the population
What does the range do
Indicates the spread of values from the lowest to highest value
Define standard deviation. Why is it usually better than the mean?
A measure of the dispersion of the values around the sample mean.
It is less affected by outliers and gives a better measure of overall variation than range.
What does a large standard deviation mean
The sample has greater variation
Outline how natural selective occurs
1) random mutation produces a new allele of a gene.
2) Although many mutations are harmful, in certain environments, the new allele is of benefit to its possessor, leading to increased reproductive success.
3) The advantageous allele is inherited by members of the next generation,
4) As a result, over many generations, the new allele increases in frequency across the population.
