MCQs on Expression of Coding Section in-Vitro
1 - Question
If an expression of the coding sequence is to be carried in the vitro, then which of the statement holds true?
a) The extract in which the host DNA constructs are incubated is capable of translation only
b) The extract in which the host DNA constructs are incubated is capable of transcription only
c) The extract is made up of lysate of E. coli cells, containing RNA polymerase, ribosomes, tRNAs etc
d) Non radiolabelled amino acids are used
Explanation: If an expression of the coding sequence is to be carried in vitro, then the extract in which host DNA constructs are incubated is capable of both transcription and translation. The extract is made up of lysate of E. coli cells, containing RNA polymerase, ribosomes, tRNAs etc. Radiolabelled amino acids are used and thus detection becomes easier.
2 - Question
If translation and transcription are taking place together, the reaction is called as ______ and if they are carried out separately, it is called as _______
a) coupled, linked
b) linked, coupled
c) grouped, separate
d) grouped, individual
Explanation: If translation and transcription are carried out together, it is known as a coupled reaction. If they are carried out separately then they are known as linked reactions.
3 - Question
If translation and transcription are carried out separately, then what is added to carry out translation?
a) DNA polymerase
b) RNA polymerase
c) Taq polymerase
d) Tfl polymerase
Explanation: The added RNA polymerase carries out the translation in a separate reaction by the use of lysate of wheat gram cells.
4 - Question
If the screening of the DNA constructs is carried out in pooled batches then it takes less time.
Explanation: If the screening of DNA constructs is carried out in pooled batches then less time is taken. Once the pooled batch is identified with recombinants then each member is screened.
5 - Question
Choose the incorrect statement for the open reading frame.
a) It is helpful in deciding whether the clone is correct or not
b) It consists of an initiation codon
c) It consists of a termination codon
d) The presence of introns doesn’t affect the open reading frame
Explanation: Open reading frame is very important in deciding whether the clone is correct or not. It consists of an initiation codon, followed by a stretch of DNA and termination codon. The presence of introns the open reading would be affected and makes detection difficult.
6 - Question
Introns are ________ in nature and the sequence is _______ than exons.
a) coding, less random
b) non-coding, less random
c) non-coding, more random
d) coding, more random
Explanation: Introns are non-coding in nature and thus the sequence is having a more random base composition than exons. Exons are coding sequences.
7 - Question
If the genome size is small, then sequencing of the entire genome is ___________
c) independent of the size of genome
d) not possible
Explanation: If the genome size is small, then the sequencing of entire genome is carried out easily. Hence, direct sequencing is carried out if the genome size is small.
8 - Question
Choose the correct statement with respect to the bacterial genome.
a) They are easy to sequence
b) They are difficult to sequence
c) Methods such as transcription and translation are satisfactory
d) Only transcription can be carried out
Explanation: Bacterial genome is of large size and thus it is difficult to carry out sequencing. Methods such as transcription and translation are unsatisfactory.
9 - Question
For identification of genes that are expressed under special conditions, _______ libraries are used.
Explanation: If genes are expressed under special conditions then specialized libraries should be used. These specialized libraries are subtractive. In this, driver and tracers are used.
10 - Question
In ______ organisms, firstly the gene is looked into model organisms.
c) both eukaryotic and prokaryotic
d) large sized
Explanation: In eukaryotic organisms, firstly the gene is looked into the model organism. In the model organism, the genome size is small. Eukaryotic organisms generally have a varying size of the genome.