12 Biology EE revision - Definitions

Stratitifed sampling is:

• a type of sampling in which a sample is taken of each strata of the population

• a type of sampling which involves using a transect

• a type of sampling in which a sample is taken at different temporal conditions

• a type of sampling in which a sample is taken along a horizontal gradient

A clade is:

• a group of organisms that share similar physical features

• a group of organisms that consist of a common ancestor and all it's lineal descendants

• a branch of a cladogram

• a group of organisms that consist of a common ancestor

An ecological niche is:

• the role and space that an organism fills in an ecosystem, including all it's interactions with the biotic factors of its environment

• the role an organisms fills in an ecosystem

• the role and space that an organism fills in an ecosystem, including all it's interactions with the biotic and abiotic factors of its environment

• the role and space that an organism fills in an ecosystem

Carrying capacity is defined as:

• the largest size a population can reach based on the available food and shelter within the ecosystem

• the maximum size a population can reach based on the limiting factors of the ecosystem

• the maximum size of population an ecosystem can support based on the resources required

• the size of the population that can be supported indefinitely on the available resources and services of that ecosystem

A keystone species is:

• a plant or animal that plays a unique and critical role in the way an ecosystem functions

• the organism at the top of the food chain/web

• a plant or animal that all other organisms in food web depend on

• an organism that if removed causes an ecosystem to collapse

A gene is:

• part of a chromosome

• a section of DNA that codes for a protein

• region/s of DNA that are made up of nucleotides; the molecular unit of heredity

• a single strand of DNA

The term genome describes:

• all the chromosomes of an organism

• all the genetic material in the chromosomes of an organism, including it's genes and DNA sequences

• the DNA found within the nucleus of an organism

• a sequence of DNA that codes for a protein

Evolution is defined as:

• the change in the genetic composition of a population

• the development of a new species due to microevolutionary change

• the change in an ecosystem over time

• the change in the genetic composition of a population during successive generations, which may result in the development of new species

Macroevolution is:

• the variation of allele frequencies at or above the level of species over geological time, resulting in the divergence of taxonomic groups, in which the descendant is in a different taxonomic group to the ancestor

• the variation of allele frequencies at or above the level of species over geological time, resulting in the convergence of taxonomic groups, in which the descendant is in the same taxonomic group to the ancestor

• small scale variation of allele frequencies within a species or population, in which the descendant is of the same taxonomic group as the ancestor

• large scale variation of allele frequencies within a species or population, in which the descendant is of the same taxonomic group as the ancestor

Microevolution is:

• the variation of allele frequencies at or above the level of species over geological time, resulting in the divergence of taxonomic groups, in which the descendant is in a different taxonomic group to the ancestor

• the variation of allele frequencies at or above the level of species over geological time, resulting in the convergence of taxonomic groups, in which the descendant is in the same taxonomic group to the ancestor

• small scale variation of allele frequencies within a species or population, in which the descendant is of the same taxonomic group as the ancestor

• large scale variation of allele frequencies within a species or population, in which the descendant is of the same taxonomic group as the ancestor