A branch of biology that deals with the heredity and variation of organisms. It studies how living things receive common traits from previous generations.


A vector is a DNA molecule used as a vehicle to artificially carry foreign genetic material into another cell, where it can be replicated or expressed. Cloning vector is a small DNA molecule capable of self-replication inside the host cell. Cloning vector is used for replicating donor DNA fragment within host cell. Vectors can replicate …

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Comparison of different helical parameters of A, B, and Z – DNA

A – DNA Much wider and flatter. Right handed helix. major grooves: Narrow and deep minor grooves: wide and shallow Glycosidic bonds – anti-form 11 base pair B – DNA Solid central core. Right handed Major groove: wide and narrow Minor groove: narrow and deep Glycosidic bond – anti-form 10 base pair Z – DNA …

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Triple stranded DNA

Structure formed in nucleic acids by sequences that are rich in Guanine. Backbone represent by tube. Likewise, Cytosine can form C-G-C. They are less stable than double helixes due to fact that the 3 negatively charged backbone strands in triple helix results in increased electrostatic repulsion.

Chargaff’s rule

1905-2002 By Erwin chargaff It states that in all DNA, Pyrimidines and Purines must have 1:1 Adenine : Thymine Cytosine : Guanine i.e., the amount of adenine = amount of thymine similarly, the amount of cytosine = amount of guanine. It indicated that DNA is symmetrical.                (A) Double bond (T)    and   (C) triple bond (G)