AS OCR Biodiversity module notes

Species: a group of individual organisms very similar in appearance, anatomy, physiology,
biochemistry and genetics, whose members are able to interbreed freely to produce fertile
offspring.

Physiology is the mechanisms in organisms e.g. muscle contraction

Habitat/ecosystem: the place where an organism lives

Biodiversity: the variety of life or range of…

Adaptation: feature that enhances survival and long term reproductive success

Selective pressure: a factor that causes individuals to reproduce successfully.

Selective advantage: a factor that enables individuals to compete, adapt and reproduce.

Heterotrophic means obtaining readymade organic food from the environment

Autotrophic means manufacturing food from inorganic compounds usually carbon…

o Take samples at regular distances across habitats
o Use random number generators to plot coordinates in a habitat
When comparing two habitats of the same study, the sample sizes should be equal.
Trees-percentage of ground cover,large plants-species per unit area, herbs-percentage
cover
Random sampling can miss rarities so a…

An evolutionary/phylogenetic tree is a hierarchy that shows common ancestors at branch points and
evolutionary distances between closed related organisms that branch off when evolved.

Prokaryotes (bacteria and blue-green algae) like viruses, have no nucleus, histones,
membrane-bound organelles or chromosomes due to pre-evolution; instead have loop of naked
DNA. They…

The EIA has made it illegal to interfere with a protected species without a license, because
loss would cause a major impact on the environment
A dichotomous key will have one question fewer than the possible species it can identify
Individuals don't evolve, individuals are selected and populations evolve
Biochemistry…

Speciation usually takes many years but depends on the pass rate of generations, which may
be a few hours in thriving bacteria.
Speciation that increases diversity may occur when:
1. A population migrates to new habitat
2. An environmental change affects group of the population
3. A reproductive barrier, is…

o Growth of fuel and food
o Regulates atmosphere and climate for respiration
o Purification of water
o Fertile soil and pollination
o Recycling of wastes
o Aesthetic-improving emotional health via beauty of nature
o Like humans, all organisms have the right to survive
Genetic erosion is caused where there…

o Facilitates scientific research
Conservation must include the human community to avoid conflicts:
o People leaving litter or feeding animals
o Illegal harvest of plants or hunting
o Animals that escape the reserve may raid farmers crops
Conservation exists in the UK as 14 National Parks and over 6000 SSSIs,…

There are three stages to EIA
o The developer makes an environmental statement assessing effect on local
biodiversity
o environmental statement is publicised
o authority considers it into their decision
The EIA aims to keep clarity of the effects of a development to the developer, planning
authority and local community…