Allele can explained by taking an example. We all have gene for eye colour but of different colours. Eye colour is defined as gene and variation in colours are defined as allele. Gene is sequence of DNA or RNA that determines a particular trait. An allele is present at fixed spot on a chromosome. Chromosomes […]


COMPLEMENTARY STRAND DNA has 4 nitrogen bases which are Adenine(A) , Guanine(G) , Thymine(T) , Cytosine(C). RNA also has 4 bases but in RNA Uracil (U) is present instead thymine. Adenine always pair with thymine by twi hydrogen bonds in DNA and to Uracil in RNA. Guanine pair with cytosine by three hydrogen bonds. In […]


GENE ACTION Gene action refers to the way in which genes exert their effects on the body. They could be dominant or recessive. Gene actions results in observable phenotype of an organism. There are three types of gene actions: Additive gene action Additive gene action states that one allele of gene is substituted by other […]


CLONING IN ANIMALS There are two approaches to make an genetic copy of an organism in a lab which are artificial embryo twinning and somatic cellular nuclear transfer. 1. Artificial Embryo Twinning Artificial embryo twinning is a quite low-tech approach to make clones. An early embryo is separated into individual cells that will divide and […]

Brief About Cloning

Cloning is an asexual organic method in which exact replica of something is produced. Many organisms produce clones naturally or artificially. Cloning in animals takes place through asexual reproduction. Synthetic embryo twinning and somatic cellular nuclear transfer are animal cloning process. Process of cloning in plants occurs by cuttings, tissue culture etc. In biotechnology, clones […]

Polymerase Chain Reaction

Polymerase Chain Reaction   PCR machine is laboratory apparatus which is used to amplify DNA segments through polymerase chain reaction (PCR). This machine maintains needed temperature and make millions of copies DNA segments by PCR. Tubes containing reaction mixtures put into a thermal block in PCR machine. This machine then increases and decreases the blocks […]