Unit 7 - Genetics, populations, evolution and ecosystems Flashcards
What is a Gene?
A squence of bases on a DNA molecule that codes for a protein
What is an allele?
A different version of a gene
What is genotype?
The genetic constitution of an organism - the alleles an orgaism has, e.g. BB, Bb or bb for eye colour
What is phenotype?
The expression of the genetic constitution and its interaction with the environment. - an organisms charcteristic, e.g. blue eyes
What is the dominant characteristic?
An allele whose characteristic apperas in the phenotype when there is only one copy present.
What is the recessive characteristic?
An allele whose characteristic only appears in the phenotype if two copies are present.
What is a codominant characteristic?
Alleles that are both expressed in the phenotype
What is the locus?
The fixed position of a gene on a chromosome
What is a homozygote?
An organism that carries two copies of the same allele, e.g. BB or bb
What is a heterozygote?
An organism that carries two different alleles, e.g. Bb
What is a carrier?
A person carrying an allele which is not expressed in the phenotype but that can be pased on to offspring.
Habitat definition
The place where an organism lives
Population definition
All the organisms of one species in a habitat
Community
Populations of different species in a habitat
Ecosystem
A community plus all of the non-living conditions in the area which it lives
Abiotic conditions
The non-living features of the ecosystem
Biotic conditions meaning
The living features of the ecosystem
Niche
The role of a species within its habitat
Adaptation
A feature that all members of a species have that increases their chance of survival and reproduction
What does a niche contain
The organisms biotic interactions
The organisms abiotic interactions
Carrying capacity
The maximum stable population size of an organism that an ecosystem can support.
Interspecific competition
When organisms of different species compete with each other
Taking a random sample of an area
1- Choose an area to sample
2-Use random sampling to avoid bias
3- Use the appropriate process (Quadrat/ Transect)
4-Repeat with as many samples as possible, reducing the likleyhood that the results are due to chance.
Taking a random sample of an area
1- Choose an area to sample
2-Use random sampling to avoid bias
3- Use the appropriate process (Quadrat/ Transect)
4-Repeat with as many samples as possible, reducing the likleyhood that the results are due to chance.