Virus and Viroids
Virus and Viroids: Overview
This Topic covers sub-topics such as Viruses, Bacteriophage, Structure of Viruses, Viral Diseases, Classification of Viruses, Viroids, Lytic Cycle, Viral Diseases in Plants and, Lysogenic Cycle of Phages
Important Questions on Virus and Viroids
Which one of the following statements about viruses is correct?
Enzymes are absent in
Influenza virus has –
Genetic material of TMV is:
Who first reported the existence of viruses?
The tail part of a bacteriophage is a narrow cylindrical part that contains a hollow tube inside it which helps it to inject the DNA into the host.
The head of the bacteriophage has a protein coat called capsid which encloses a highly folded double-stranded DNA.
Bacteriophages are the viruses that infect the bacteria.
Name the following.
The Virus that has single-stranded RNA and lacks a protein coat.
Identify the correct statement/s about viruses.
Assertion (A): DNA from Bacteriophage head passes through tail core through plasma membrane and enters bacterial cell.
Reason (R): Plasma membrane of the host cell gets dissolved due to lysozyme and releases the new virions.
Assertion (A): Enveloped viruses like measles, Rubella and Adenovirus attached to the susceptible host by spikes.
Reason Influenza virus is an enveloped virus attached to susceptible host by spikes.
The infectious diseases which are emerging include
I. Severe Acute Respiratory Syndrome
II. Dengue Fever
III. Mad Cow Disease
IV. Tuberculosis
The correct combination is:
In the Bacteriophage the arrangement of its parts (Top to bottom) are as follow:
I. Head containing
II. Sheath
III. Collar
IV. Tail fibres
V. Base plate
The correct sequence is:
Arrange the following steps in the order of their occurance in the lytic cycle of a phage.
i) Maturation phase
ii) Penetration phase
iii) Attachment
iv) Release phase
v) Biosynthesis
The correct combination is
Which among the following is incorrect with respect to virus?
On the basis of host attacked, types of viruses are
