Question

What is heredity and they types?​

Answer 1

Answer:

Heredity refers to the genetic heritage passed down by our biological parents.

The description of a mode of biological inheritance consists of three main categories:

1. Number of involved loci

Monogenetic (also called "simple") – one locus

Oligogenic – few loci

Polygenetic – many loci

2. Involved chromosomes

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

3. Correlation genotype–phenotype

Dominant

Intermediate (also called "codominant")

Recessive

Overdominant

Underdominant

These three categories are part of every exact description of a mode of inheritance in the above order. In addition, more specifications may be added as follows:

4. Coincidental and environmental interactions

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)

5. Sex-linked interactions

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)

6. Locus–locus interactions

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 also achieved primarily through statistical analysis of pedigree data. In case the involved loci are known, methods of molecular genetics can also be employed.