Topic 1: Describing Biodiversity
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define biodiversity
amount of variety among living things
define species
group of living organisms consisting of similar individuals
what is the word to describe biodiversity WITHIN a species
genetic variation
what does genetic variation refer to
differences between members of a single species (in terms of the alleles they have for a particular gene) –> imagine, humans are all the same species but we still look different
define phenotypic variation
physical differences
what are alleles
one of two or more alternative forms of a gene
what does a large gene pool mean for a species
the species has many different alleles for its genes
genotypic variation
differences between members of a species in the alleles they contain for genes
define biome
larrge geographic region characterised by the form of the species living there (certain climate and certain types of living things)
define species richness
simply the no. of species counted in the sampling process
name a point of usefulness and a limitation for using species richness
useful: gives clear idea of how many species inhabit an ecosystem limitation: no indication of how plentiful each species is, nor the evenness of distribution
define relative species abundance/ evenness
the no. of individuals in each species counted in proportion to other species sampled
define percentage frequency
% of quadrats in which a species is counted - helps indicate evenness of species
define simpson’s diversity index
used to measure the diversity of an ecosystem (based on data from sampling); formula returns a value between 0 (not diverse) and 1 (very diverse)
spatial vs temporal
spatial - over space/ temporal - over time
what is the general species distribution pattern at a macro level
clumped
what is a common reason for uniform spatial distribution in species
competition
what is a taxon
a group within a classification system
what are the different taxonomic levels
Kingdom Phylum Class Order Family Genus Species
what are the characteristics of r - selected species
produce many offspring, short life span, little parental care, shorter time to sexual maturity, short pregnancy
what are the characteristics of K- selected species
few offspring, invest time and resources into caring for young, longer time to reach sexual maturity, longer life span, longer pregnancy
what is molecular sequencing
comparing genomes of different species
define clade
a group of taxa (a phylogenetic group) which represents all the evolutionary descendants of a common ancestor
what are the three assumptions that cladistics is based on
• any group of living things is related by descendant to a common ancestor • lineages BIFURICATE - (divide/ branch in two) • physical changes occur in every lineage