Biological inheritance is the process by which an offspring cell or organism acquires or becomes predisposed to characteristics of its parent cell or organism. Through inheritance, variations exhibited by individuals can accumulate and cause a species to evolve.
The study of biological inheritance is called genetics, which includes epigenetics.
The description of a mode of biological inheritance consists of three main categories:
-Monogenetic (also called "simple") - one Locus
-Oligogenetic - few Loci
-Polygenetic - many Loci
-Autosomal - Loci are not situated on a sex chromosome
-Gonosomal - Loci are situated on a sex chromosome

-X-Chromosomal - Loci are situated on the X chromosome (the more common case)
-Y-Chromosomal - Loci are situated on the Y chromosome
-Mitochondrial - Loci are situated on the mitochondrial DNA
-Dominant
-Intermediate (also called "codominant")
-Recessive
These three categories are part of every exact description of a mode of inheritance in the above order. Additionally, more specifications may be added as follows:
-Penetrance

-Complete
-Incomplete (percentual number)
-Expressivity

-Invariable
-Variable
-Heritability (in polygenetic and sometimes also in oligogenetic modes of inheritance)
-Maternal or paternal imprinting phenomena (also see epigenetics)
-Sex-linked inheritance (Gonosomal Loci)
-Sex-limited phenotype expression (e.g. Cryptorchism)
-Inheritance through the maternal line (in case of Mitochondrial DNA loci)
-Inheritance through the paternal line (in case of Y-chromosomal loci)
-Epistasis with other Loci (e.g. overdominance)
-Gene coupling with other Loci (also see crossing over)
-Homozygotous lethal factors
-Semi-lethal factors
Determination and description of a mode of inheritance is primarily achieved through statistical analysis of pedigree data. In case the involved loci are known, methods of molecular genetics can also be employed.

1. Number of involved Loci
2. Involved Chromosomes
3. Correlation genotype-phenotype
Coincidental and environmental interactions
Gender interactions
Locus-Locus-Interactions