Different Types of DNA
A | B DNA | |
B |
C DNA |
|
C |
A DNA |
|
D |
Z DNA |
Which form of DNA is predominantly seen
A |
B DNA |
|
B |
C DNA |
|
C |
A DNA |
|
D |
Z DNA |
Ans-A- i.e B-DNA
Physiologically most common is B-DNAQ
à Under low salt and high degree of hydration B-DNA is usually found
àUnder high salt concentration and low degree of hydration A-DNA is usually found
àThe distance spanned by one turn of B-DNA is 3.4 nm (34 A⁰).
àThe width of the double helix in B-DNA is 2 nm (20A⁰)
Triplex DNA is clue to
A |
Hoogsteen Pairing |
|
B |
Palindromic sequences |
|
C |
Large no. of guanosine repeats |
|
D |
PolypYrimidine tracts |
Triple- stranded DNA- forms hydrogen bonds with another surface of the double helix through called Hoogsteenpairs.
Which model of DNA was discovered by Watson and Crick
A |
A- DNA |
|
B |
B- DNA |
|
C |
C-DNA |
|
D |
Z- DNA |
Most common form.
Right handed double helix.
Highly flexible.
Watson and Crick model describes the B- form of DNA.