Question

What is true about viruses?
(a)They can be crystallized and stored for several years
(b)Viruses do not occur as parasites in living cells
(c)They can be cultured on artificial media
(d)They are devoid of the genetic material of their own

Answer 1

Hint: To study their structural features, viruses may undergo a procedure that is widely used with the help of an X-ray. They are generally cultivated in cell culture. Outside the host cell, viruses are inert. It is possible to conserve viruses. Cryopreservation is often used for this purpose. Either DNA or RNA is found in viruses.

Complete answer:
-Crystallization refers to the mechanism by which viral components are converted into structured solid particles. They can store these crystallized viruses for many years.
-The first virus to be crystallized is the tobacco mosaic virus in 1935. Viruses may be precipitated from suspensions and, in the form of crystals, can be crystallized. The crystallized forms maintain their infection ability.

Additional Information: -Viruses are infectious particles that are non-cellular and ultramicroscopic. Only when they are within the living host cells are they active. They are good chemical substances outside the host. So, they do not have an autonomous life of their own. There is only one form of nucleic acid in the vast majority of viruses: DNA or RNA, but not both. Viruses are fully dependent (i.e., they are strict intracellular parasites) on a host cell for replication. They are considered as perfect obligate parasites.
-To go from one host cell to another, viral pieces must be assembled into complete viruses (virions). Since viruses lack their metabolic machinery and are fully dependent on their host cell for replication, they can not be produced in the media of synthetic culture. In animals, embryonic eggs, or in cell cultures where animal host cells are grown in a synthetic medium, animal viruses are usually grown and the viruses are then grown in these cells. In an artificial medium, viruses cannot be grown.
So, the correct answer is, ‘They can be crystallized and stored for several years’.

Note: Infectious agents with both living and nonliving features are viruses. Animals, plants, and even other microorganisms may be infected by them. Bacteriophages are called viruses that infect only bacteria and those that infect only fungi are called mycophages. Some viruses infect other viruses, called virophages. Based on the large number of protein folds encoded by viral genomes that are shared with the genomes of cells, viruses have been declared as living entities. This suggests that from several ancient cells, viruses probably emerged.