inheritance terms

hemizygous

the condition of a gene where only one set of chromosomes from a chromosomal pair is observed. 

(only in males where it is on sex linked x gene)

DNA methylation

Process by which a methyl group is added to DNA molecules, often at cytosine residues, resulting in changes in gene expression without altering the DNA sequence.

epigenetics

The study of heritable changes in gene expression without altering the DNA sequence. It involves modifications to DNA or associated proteins that can be passed on to future generations.

histones

a protein that provides structural support for a chromosome. Each chromosome contains a long molecule of DNA, which must fit into the cell nucleus. To do that, the DNA wraps around complexes of histone proteins, giving the chromosome a more compact shape.

heterozygous

having different alleles for a particular trait. 

homozygous

having the same alleles for a particular trait.

genotype

the genetic makeup of an organism

phenotype

an individual's observable traits