Question

Which statement is wrong for viruses?
(a)All are parasites
(b)All of them have helical symmetry
(c)They have ability to synthesize nucleic acids
(d)Antibiotic have no effect on them

Answer 1

Hint: They are sub microscopic infective agents. They're cellular, that is, they contain no cytoplasm or cellular organelles. They perform no metabolism on their own and must replicate using the host cell's metabolic machinery. The overwhelming majority does possess either DNA or RNA but not both.

Complete answer:
Symmetry refers to the way during which capsomere units are arranged in viral capsid. Two sorts of symmetry are recognized within the viruses which corresponds to two primary shapes i.e. rod and spherical shape of virus. Rod shaped viruses possess helical symmetry and spherical shaped viruses possess icosahedral symmetry. So, all viruses don't possess helical symmetry.

Additional Information: Viruses are almost like obligate intracellular parasites as they lack the means for self-reproduction outside a number cell, viruses are generally not considered to be true living organisms. A primary reason is that viruses don't possess a cell membrane or metabolise on their own - characteristics of all living organisms. Examples of common human diseases caused by viruses include the cold, the flu, chickenpox and cold sores.
They have the ability to synthesize nucleic acids by replication. They insert their genetic material which replicates by utilizing host cell machinery and reform their structure and attain viable structure capable enough to affect other cells.
Antibiotics are strong medicines that treat bacterial infections. Antibiotics won't treat viral infections because they cannot kill viruses. Antibiotics don't act against viruses as they're made from polymorphic protein coat.
So, the correct answer is ‘All of them have helical symmetry’.

Note: Viruses are a crucial natural means of transferring genes between different species, which increases genetic diversity and drives evolution.
Viruses are the foremost abundant biological entity in aquatic environments. There are about ten million of them during a teaspoon of seawater. Most of those viruses are bacteriophages infecting heterotrophic bacteria and cyanophages infecting cyanobacteria and they are essential to the regulation of saltwater and freshwater ecosystems