Biology Questions and Answers – Transcription Unit and the Gene

«
»

This set of Biology Multiple Choice Questions & Answers (MCQs) focuses on “Transcription Unit and the Gene”.

1. It is difficult to define a gene in terms of its DNA sequence.
a) True
b) False
View Answer

Answer: a
Explanation: Genes are the functional units of a living organism. They are the information carriers that are present on the DNA. But a gene cannot be entirely defined based on its DNA sequence alone. The DNA sequence coding for either the tRNA or the rRNA also defines the gene.
advertisement

2. What is a cistron?
a) A gene coding for RNA
b) A segment of DNA responsible for producing the nuclear coat
c) A segment of DNA coding for polypeptides
d) A gene coding for the template strand of DNA
View Answer

Answer: c
Explanation: A cistron is the segment of a DNA. It is responsible for coding polypeptide chains. This is seen during the process of protein synthesis.

3. Which of the following is monocistronic?
a) Fungi
b) Eukaryotes
c) Bacteria
d) Virus
View Answer

Answer: b
Explanation: Cistrons are the segments of the DNA helical structure which code for polypeptide chains. The structural gene in the transcription unit can be either monocistronic or polycistronic. The monocistronic genes are mostly present in eukaryotes.
advertisement
advertisement

4. Which of the following is polycistronic?
a) Bacteria
b) Rats
c) Snakes
d) Hamster
View Answer

Answer: a
Explanation: The polycistronic organisms can code for more than one polypeptide sequence as individuals inside the RNA molecule. Examples of such are the bacteria and prokaryotes.

5. The genes in eukaryotic organisms are split.
a) True
b) False
View Answer

Answer: a
Explanation: The presence of monocistronic structural genes results in the formation of interrupted coding sequences. The monocistronic structural genes are present in the eukaryotes. So, their genes are split.
advertisement

6. Which of the following is the key difference between exons and introns?

S. No Exons Introns
I They are non-coding sequences They are the coding sequences
II They are interrupted by Introns They appear in mature RNA
III They appear in mature RNA They interrupt the sequences of the exons
IV They are the unexpressed sequences They appear in non-coding sequences

a) I
b) II
c) III
d) IV
View Answer

Answer: c
Explanation: The sequences of the genes which appear in the mature or processed RNA are called as exons. They are the coding sequences of the gene. These sequences are interrupted by introns. Introns are the intervening sequences which aren’t present in both the mature or the processed RNA.
advertisement

Sanfoundry Global Education & Learning Series – Biology – Class 12.

To practice all areas of Biology, here is complete set of 1000+ Multiple Choice Questions and Answers.

advertisement

Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

advertisement
advertisement
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn | Youtube | Instagram | Facebook | Twitter