#Question id: 800
#Unit 1. Structure and Function of Biomolecules
Following table lists the two major forms of DNA duplexes, conformation of base attached to the sugar and the nature of major and minor grooves.
|
DNA duplex |
Properties |
|
(A) A
form |
(i) Syn
conformation of the base to sugar |
|
(B) B
form |
(ii) Anti
conformation of the base to sugar |
|
|
(iii) Wide
major groove |
|
|
(iv)
Narrow major groove |
|
|
(v) Wide
minor groove |
|
|
(vi) Narrow
minor groove |
|
|
(vii) C-3’
endo sugar puckering |
|
|
(viii) C-2’
endo sugar puckering |
#Question id: 801
#Unit 1. Structure and Function of Biomolecules
Identify the type of DNA from the structures given below and match the correct form with its characteristics described.
#Question id: 802
#Unit 1. Structure and Function of Biomolecules
A single-stranded DNA molecule contains 40 nucleotides with equal amounts of A, C, G, and T. This DNA strand can combine with a complementary DNA strand to form a double-stranded DNA molecule. Which is a possible sequence and structure for this DNA molecule?
#Question id: 803
#Unit 1. Structure and Function of Biomolecules
A single-stranded DNA molecule contains 40 nucleotides and has the sequence 5’-(GA)20-3’. When this single strand binds to a complementary DNA strand to form a B-DNA structure,
#Question id: 804
#Unit 1. Structure and Function of Biomolecules
With respect to microRNAs, which, if any, of the following statements, is false?
a) A microRNA normally works by binding to perfectly complementary sequences within an RNA transcript, usually an mRNA.
b) Like the great majority of mRNAs an miRNA is usually produced as a larger precursor RNA that is capped and has a 3’ poly(A) tail.
c) The precursor miRNA undergoes different types of post-transcriptional cleavage by endoribonucleases that are specific for double-stranded target sequences.
d) A nuclear endoribonuclease called dicer cleaves the miRNA precursor so that it forms a stem-loop RNA.
#Question id: 804
#Unit 1. Structure and Function of Biomolecules
With respect to microRNAs, which, if any, of the following statements, is false?
a) A microRNA normally works by binding to perfectly complementary sequences within an RNA transcript, usually an mRNA.
b) Like the great majority of mRNAs an miRNA is usually produced as a larger precursor RNA that is capped and has a 3’ poly(A) tail.
c) The precursor miRNA undergoes different types of post-transcriptional cleavage by endoribonucleases that are specific for double-stranded target sequences.
d) A nuclear endoribonuclease called dicer cleaves the miRNA precursor so that it forms a stem-loop RNA.