Biology Unit 3 & 4 QCE

the variety of species and ecosystems

The number of different alleles possessed by a species.a change to the allele frequency or gene code occurs, a smaller proportion is affected if there are many more alleles compared to only a small amount

the number of different species at a particular time in a particular ecosystem
the more species, a change is likely to only affect a small proportion of them rather than the entire or half the population due to different niches and adaptations of abiotic factors.

number of different ecosystems or biomes and the variation between them

the study of plants and animals

Non-living factors (e.g., salinity and pH of soil, oxygen percentage, temperature etc.)

Living factors (interactions with other organisms, predator-prey relationships, competition, symbiosis)

the measure of diversity for where a species is found

measure for diversity for how many of a species there is

Ecological sampling. area marked out with a frame for the purpose of gathering data related to populations of organisms in each area.

Several quadrats placed randomly around a habit can provide information regarding abundance and density of species (useful for percentage frequency)

Line marked out randomly through a habitat. Every organism on the line at regular intervals or within the transect is recorded. Two methods: Line Transects and Belt Transects

are time efficient and can minimise disturbance to environment however not as precise (only really measures distribution)

extend out a specific distance to either side of the line and provide accurate estimations of distribution and abundance.

number of different species within an area (only informs about distribution)

(relative abundance): Tells you how many of a species there is in relation to the total number of individuals.