Following are certain statements regarding furanocoumarins;

 a) furanocoumarins have an attached furan ring

 b) These compounds are toxic until they are activated by sunlight in the ultraviolet A (UV-A) region (320–400 nm)  

 c) Light activated furanocoumarins can insert themselves into the double helix of DNA and bind to the pyrimidine bases, thus blocking transcription and repair and leading eventually to cell death   

 d) Phototoxic furanocoumarins are especially abundant in members of the Umbelliferae family, including celery, parsnip, and parsley.

 Which of the following combination from the above statements is correct?

#Question id: 3685

#Unit 3. Fundamental Processes

In prokaryotes, DNA replication begins at a single site that is rich in AT nucleotide sequence, where two strands unwind and separate. This ATP dependent process catalyzed by a protein

#Question id: 3686

#Unit 3. Fundamental Processes

The short strand of ........ primer is required for the replication of DNA:

#Question id: 3687

#Unit 3. Fundamental Processes

As the two strands of the double helix are separated, the positive supercoiling interferes with the further unwinding of DNA. Which of the following enzyme makes a break in a strand of DNA to release the supercoiling and facilitate the replication to occur?

#Question id: 3688

#Unit 3. Fundamental Processes

Which of the following enzyme has a unique ability to introduce positive and negative supercoiling of the DNA and it is the target for antibacterial agents such as ciprofloxacin/quinolones?

#Question id: 3689

#Unit 3. Fundamental Processes

DNA replication is bidirectional and anti-parallel. Which of the statement is FALSE regarding the DNA replication?

#Question id: 3690

#Unit 3. Fundamental Processes

The DNA polymerase is a template-directed enzyme that synthesizes new complementary strand from a parent strand but it requires the existing short nucleotide sequence for its elongation. Which of the following enzyme is required for the synthesis of this primer?