Biodiversity - Yr 1 Flashcards
Genetic Diversity
The greater the number of different alleles that all members of a species possess, the greater the genetic diversity of that species.
Allele frequency
the number of times an allele occurs within the gene pool in a population, relative to all others at same locus
Gene pool
all the different alleles of all the genes of all the individuals in a population at any one time
Natural Selection
Natural Selection is Darwin’s theory to explain the mechanism of evolution. The process by which organisms better adapted to their environment survive and reproduce and pass on their advantageous alleles to the their offspring, whilst those less well adapted fail to do so.
Directional selection
Favours one extreme of the range of characteristics and the other extreme is selected against – shift in population curve
Stabilising selection
Favours the mean of the distribution because the extremes are at a selective disadvantage – frequency of mean phenotype increases
Polygenes
Group of genes that are responsible for controlling a characteristic.
Normal distribution curve
A bell-shaped curve produced when a certain distribution is plotted on a graph
Biodiversity
The range and variety of genes, species and habitats within a particular region. Made up of three components: genetic diversity, species diversity and ecosystem diversity.
Species
A group of organisms that have a common ancestry and so share the same genes and are capable of breeding together to produce fertile offspring - are reproductively separated from other species.
Binomial naming system
Linnaeus’ system to name species. 1st: Generic name (genus). 2nd: Specific name (species) E.g. Felix tigris
Hierarchy
Groups within larger groups; with no overlap between groups at each rank
Artificial Classification
Process of classifying organisms based on differences useful at time e.g. colour, size, number of legs
Phylogenetic Classification
Process of classifying organisms based upon evolutionary relationships between organisms and ancestors
Analogous Characteristics
Characteristics with the same function not the same evolutionary origins. e.g. wings of butterflies and birds used for flight but originated in different ways.
Homologous Characteristics
Characteristics with similar evolutionary origins regardless of their functions in the adult of a species e.g. wing of a bird, arm of a human and front leg of a horse
Taxon
Each group within a phylogenetic biological classification (pl. taxa)
Courtship behaviour
A specialised behaviour that precedes the fertilisation of eggs by a male to ensure successful reproduction.
Classification
Organisation of living organisms into groups
Taxonomy
The practice of biological classification
Domain
Largest taxon either bacteria, archaea and eukarya
Kingdom
Second largest taxon of classification. Eukarya domain divides into Protoctista, Fungi, Plantae and Animalia.
Community
The organisms of all species that live in the same area
Population
A group of organisms of the same species occupying a particular space at a particular time that can potentially interbreed.
Species diversity
Number of different species and number of individuals of each species within any one community
Ecosystem Diversity
Range of different habitats within a particular area
Genetic diversity
Variety of genes possessed by individuals that make up any one species
Species richness
The number of different species represented in an ecological community. It does not take account the abundances of species or their relative abundance distributions.
Index of diversity
A formula is used to quantify the biodiversity of a habitat. It takes into account the number of species present as well as the abundance of each species.
Biomass
The total mass of living material, normally measured in a specific area over a given period of time
Conservation
Management of the Earth’s natural resources in such a way that maximum use can be made of them in the future
Intercropping
The practice of growing two or more crops in close proximity usually to produce a greater yield on a piece of land.
Habitat
The place where an organism normally lives
Random sampling
Sampling a population to eliminate bias e.g. grid square and co-ordinates
Sampling bias
When a sample is collected in such a way that some members of the intended population are more or less likely to be included than others. The data you collect may therefore not be accurate or represent the group.
Sample size
The number of observations in a sample.
Mean
A type of average where you add up all of the numbers then divide by how many numbers there are.
Median
A type of average where you place the numbers you are given in value order and find the middle number.
Mode
A type of average that is the number that occurs the most often.
Standard deviation
A measure of how spread out about the mean your values are. The more spread out the data the higher it will be.
