Figure1.1: Chromosome with its chromatids
• Heredity is central to life and it is the phenomenon of passing of
characteristics and traits from parents to kids. Proteins, DNA and RNA are
required for processing heredity.
• Hereditary Material is DNA (deoxyribonucleic acid) that is present in all
living cells including humans and other organisms. Interestingly, in a human
the entire cells contain same DNA (hereditary material). All of the cells living
on earth do store their information in DNA molecules the double stranded
• Building Blocks of DNA are simple subunits consists of nucleotides, sugar-
phosphate with one of the nitrogen side molecule and a base.
• Structure of DNA is formed by paired, long and un-branched chains. All
type of chains contains four same monomers. The single strand DNA
nucleotides join with another strand by sugar-phosphate and develop into
double stranded DNA. Here sugar-phosphate acts as backbone of strands and
it is of asymmetric nature.
• Monomers or Bases are nucleotide compounds made up of chemical
combinations and these nucleotides encode genetic information by having
long linear sequencing. These nucleotides are Adenine-A, Thymine-T,
Guanine-G and Cytosine-C.