Defintions Flashcards
Gross primary production
The chemical energy store in plant biomass in a given area or volume,
Net primary production
A chemical energy store in plant biomass after respirator losses to the environment have been taken into account
What is primary or secondary productivity
The rate of primary or secondary production, measured as biomass in given area in a given time
Homeostasis
Physiological control systems that maintain the internal environment within restricted limits
Genotype
The genetic constitution of an organism
Phenotype
The expression of this genetic constitution and its interaction with the environment
population
A Group of organisms of the same species occupying a particular space at a particular time that can potentially interbreed
Community
The non living components of its environment together form an ecosystem
Epigenetics
The heritable changes in gene function, without changes to the base sequence of dna
Gene
A sequence of bases on a DNA molecule that codes for a protein which results in a characteristic
Allele
A differnt version of a gene
Dominant
An allele whose characteristic appears in the phenotypes even when there is only one copy
Recessive
An allele whose characteristic only appears in the phenotype if two copies are present
Codominant
Alleles that are both expressed in the phenotype- neither is rescessibe
Locus
A fixed position of a gene on a chromosome
Homozygote
An organism that carries two copies of the same allele
Heterozygote
An organism that carries two differnt alleles
Carrier
A person carrying an alleles which is not express in the phenotype but that can be passed on to ofspreing
Genetic drift
Random change in allele frequencies in a small populations by chance
Founder effect
A type of genetic drift occurring when a new colony is started by a few members of the origional population
Bottle neck effect
A sharp reduction in population size due to environmental events leading to reduced genetic diversity
Natural selection
A mechanism where individuals with better suited traits have high survival reproductive success
Evolution
The gradual change in allele frequencies in a population over generations
