t7 inheritance Flashcards
definition of ecosystem
all living and non-living components in a particular area and their interactions
definition of community
all of the populations of different species living in an area at the same time
definition of population
group of individuals of ONE species occupying the same area at the same time. potentially able to interbreed
definition of carrying capacity
size of a population that can be supported by an ecosystem
definition of habitat
place where an organism normally lives - can have microhabitats
definition of ecological niche
role of a species within its habitat
what is the competitive exclusion principle
no 2 species can occupy the same niche at the same time
definition of abundance
number of individuals of a species in a given space.
2 types of speciation (brief)
- allopatric
- sympatric
what is allopatric speciation
-formation of 2 species from an original one due to a geographical barrier
-separated organisms experience different selection pressures so have different allele frequencies and different phenotype frequencies
-eventually become so different they can no longer produce fertile offspring
what is sympatric speciation
-formation of 2 species from an original one without a geographical barrier
-a mutation occurs that prevents members breeding w those that dont have the mutation (eg. diff markings, diff courtship behaviour)
-causes reproductive isolation
definition of phenotype
expression of the genetic constitution of an organism and its interaction with the environment
definition of genotype
genetic constitution of an organism (all of the alleles it has)
conditions for chi squared
-large sample size (over 20)
-data must fall into discrete categories
-only raw counts (no percentages/rates)
what is chi squared used for
-used to compare expected results with observed ones
definition of codominant alleles
alleles that are equally dominant and both expressed in the phenotype
definition of dihybrid inheritance
inheritance of 2 characteristics determined by 2 diff genes located on 2 diff chromosomes
dihybrid: phenotype ratio for 2 heterozygous parents
9:3:3:1
dihybrid: phenotype ratio for 1 hetero, 1 homo recessive
1:1:1:1
recessive epistasis phenotype ratio
9:4:3
when is hardy-weinberg equation used
used to estimate allele and genotype frequencies in a population
definition of epistasis
interaction of genes, where a gene at one locus masks or suppresses the expression of a second gene
conditions for hardy weinberg
-large population/sample
-mating is random
-no migration
-no mutation
-no selection pressures
definition of gene pool
the complete range of alleles in a population
definition of a species
similar organisms that share a common ancestry and the same genes that can reproduce to give fertile offspring
definition of allele frequency
how often a certain allele occurs within a population/gene pool
definition of evolution
change in frequency of an allele in a population over time
dominant epistasis phenotype ratio
12:3:1
definition of autosomal linkage
inheritance of 2 genes located on the SAME chromosome (not a sex chromosome)
