Paper 2 Definitions Flashcards
(21 cards)
Population
The number of organisms of the same species living in a particular area at the same time
Gene pool
All the different alleles within a populations
Allele frequency
Proportion of an allele among all allele copies in a population
Allele
A different version of a gene
Genotype
Total amount of genetic material within an organism
Phenotype
The physics expression of the genes and its interaction with the environment
Co dominant
Allele that are both expressed in the phenotype
Locus
Fixed position of a gene on a chromosome
Carrier
Person carrying an allele which is not expressed in the phenotype but can be passed onto the offspring
Ratio of monohybrid cross
( all heterozygous )
3:1
Ratio of dihybrid cross ( all heterozygous )
9:3:3:1
Ratio of codominant ( all hetrozygous)
1:2:1
Sex linked
Allele is located on a sex chromosome
Autosomal linkage
Genes on the same chromosome - no crossing over as genes are close together on the chromosome
No independent segregation
Epistasis
One gene makes the expression of another gene at a different locus
Epistasis recessive ratio
9:3:4
Epistasis dominant ratio
12:3:1
Species
Similar organisms which can reproduce to produce fertile offspring
Taxes
Organisms move towards or away from a directional stimulus eg light
Kineses
Organisms movement is affected by non-directional stimulus eg temp
Myogenic
Hearts ability to contract and relax without receiving signals from nerves
