The human species is controlled (defined) by 46-chromosomes. These 46 chromosomes are packaged in 23 pair, numbered 1-23. [Imagine that!] Numbers 1-22 are called "somatic". They control the cells. Number 23 gets all the fun, and is called the "sex chromosome". It is passed down during reproduction. The Y-chromosome is transmitted from father to son. The X-chromosome is transmitted from father and mother to daughter. [Gives the mitrochrondial DNA written as mtDNA.]
Each chromosome is a series of nucleotide bases which are arranged in units of three (3). These units 0f three (3) are called the codon. It is a series of codons that make proteins. A series of codons that work is called a "gene"!
The "gene" falls along a section of the much longer DNA molecule. [Containing multiple genes.] Its location is called a "loci". Each gene has two sides opposite. These sides are called "alleles". Allele numbers identify the address along the long strand of DNA molecules (genome). A loci number gives the street address of these alleles. [Its cytogenetic location!]
DYS nomenclature is: D = DNA, Y = Y-chromosome, S = (unique) segment. This identifies the unique location along the Y-chromosome where a change (mutation) has occurred. A single nucleotide change is called a SNP (snip). A number of changes that have occurred very near to one another, is called STR (short tandem repeat.)
Haplogroups are determined by the methods called SNP analysis.
Haplotypes are determined by STR analysis.