10 Biodiversity

When organisms are able to breed and make fertile offspring

1.Reproduce and pass on advantageous alleles 2. Courtship behaviour for successful mating and species recognition

a SEQUENCE of… - dance moves - sounds - release of pheromones (chemicals) - display of colourful feathers - fighting

• Ensures successful reproduction • Ensures survival of offspring

• Helps them recognise members of their own species and opposite sex • Synchronises mating behaviour (indicates sexually mature and in season)

• parents form a pair bond • choosing a strong and healthy mate

Genus, species e.g Homo sapien

• universally used • can share data • gives you more information than the common name would

Arranges species into groups according to their evolutionary origins and relationships

• who’s related to whom • how closely related they are

How organisms have evolved from shared common ancestors

Physical and biochemical similarities

• Smaller groups arranged in larger groups • there is no overlap between groups

Variety of life that is measured on different scales (small local habitat or the entire Earth)

• Species richness • Index of diversity

The number of different species present in a community

• the relationship between the number of species in a community • the number of individuals in each species

Modern farming techniques are designed to maximise food production but will reduce biodiversity

• Removes habitats (e.g hedgerow removal) • Uses monocultures which reduces species richness • Use pesticides and herbicides which kills insects and unwanted plants reducing food SOURCES and HABITATS for other organisms • Overuse of fertilisers leads to eutrophication and damage to aquatic systems

The variety of alleles within a species

Comparing…. 1. frequency of measurable or observable characteristics (e.g flower colour) however this is less reliable due to environmental influences (!) 2. Base sequence of DNA provides direct measure of genetic differences (!) 3. Base sequence of mRNA reflects transcribed DNA coding sequence • Amino acid sequence of proteins results of translation of mRNA reflects genetic differences at a functional level (!) = more accurate

Too time consuming to record data on every individual of the population

• Random sampling to remove bias • Take large samples so results are representative • Calculate mean to summarise data • Calculate standard deviation to show spread of values around the mean (how much variation exists) • Interpret and compare values from statistics and standard deviation to see if results are significant