Question

In Cyanophage, the genetic material is
A. RNA
B. DNA
C. RNA and DNA
D. Protein

Answer 1

Hint:-
- Cyanophages are viruses that infect cyanobacteria, also known as Cyanophyta or blue- green algae.
- Cyanophages can be found in both freshwater and marine environments. These are the viruses that infect cultivated mushrooms and cause die back disease.
- The first cyanophage was discovered in 1963 and is classified within the bacteriophage families.

Complete Answer:-Cyanophages have a tail and a protein capsid surrounding genetic material.
The double stranded DNA is the genetic material in cyanophages and is 45 kbp long approximately.
- In some cyanophages, DNA encodes for photosynthetic genes or genes involved with phosphate metabolism.
- The tail binds the virus to the host cell and transfers viral DNA to the host cell upon infection.
- The host range of cyanophages is very complex and plays an important role in controlling cyanobacterial populations.
- The cyanophage replication is heavily dependent on the diel cycle. The first step in the infectious cycle is for the cyanophage to make contact and bind the cyanobacteria, this absorption is heavily dependent on light intensity.
- After three hours of infection, degradation of the host DNA begins and by the end of 7 hours it is converted into acid soluble material.
- Sufficient amounts of degraded DNA material is used up in boiling of viral DNA.

A. RNA (Ribonucleic acid) is not genetic material as it is not dominant in cyanophages. So, option A is incorrect.
B. DNA (Deoxyribonucleic acid) is genetic material of cyanophages as it is predominant. Therefore, this option is correct.
D. Proteins surround the genetic material. Hence, it is not the correct option.

C. Only DNA is genetic material not RNA as explained above. So, this option is also incorrect.

Note:- Cyanophages were named after their hosts. However, the ability of cyanophages to infect multiple hosts and lack of a universal naming system can cause difficulties with their taxonomic classification. Cyanophages collide with bacteria and use the receptor binding proteins to recognize cell surface proteins.