Type of variation where a characteristic falls into distinct groups. This is controlled by a single gene.
Gene
A short section of DNA that codes for a particular characteristic (it codes for a protein)
Alleles
Different forms of the same gene
Phenotype
Describes the outward appearance of the organism and is described in words
Genotype
Describes the set of genes it possesses. This is represented as different letters that refer to the different alleles for the gene.
Dominant
These alleles always show up in the appearance of an organism, even if only one copy is present
Recessive
These alleles only show up in the appearance of an organism if there are two copies present in the genotype
Heterozygous
If the two alleles are different (e.g. Tt)
Homozygous
If the two alleles are the same (e.g. TT or tt)
P generation
Parental generation
F1 generation
First generation after the parents
F2 generation
Second generation after the parental generation
Polygenic inheritance
Characteristics that are controlled by many genes that act together. They show continuous variation and most characteristics show this type of inheritance.
Single gene inheritance
When a characteristic is controlled by only one gene and shows discrete variation
