Double helical structure of DNA was  given by ____________.

__________is  purine nitrogen base.

__________ are the hereditary material of a cell.

_________are also known as gametes.

____________are the units  of heredity  and are  responsible for the characteristics features.

__________is a picture of  a person's chromosome.

A prokaryotic  cell has  only one chromosome which is ___________ in shape.

When the centromere is slightly displaced from the centre  it is said to be __________.

Centromere present at the proximal end  is called ___________.

Chromosomes  come in pairs and they are called ___________.