8(i)Name the infectious living fluid and the scientist who proposed it.
(ii) What are virions?
(iii]What are viroid and specify the genetic material
(iv) Name the genetic material in bacteriophage.
Answers
(i) He named the new pathogen virus to indicate its non-bacterial nature. Beijerinck asserted that the virus was somewhat liquid in nature, calling it "contagium vivum fluidum" (contagious living fluid)
(ii) The complete, infective form of a virus outside a host cell, with a core of RNA and a capsid.
(iii) An infectious entity affecting plants, smaller than a virus and consisting only of nucleic acid without a protein coat.Like some viruses, viroids are little more than a strand of genetic material called ribonucleic acid (RNA). ... Unlike most viral RNAs, viroids can't make proteins, nor do they wear a protective protein shell to avoid being torn apart by a host plant's powerful enzymes.
(iv) Like all viruses, phages are simple organisms that consist of a core of genetic material (nucleic acid) surrounded by a protein capsid. The nucleic acid may be either DNA or RNA and may be double-stranded or single-stranded.
Answer:
(i) Tobacco was the infectious living fluid and the scientist was Martinus beijerinck .
(ii)A virions is an entire virus particle consisting of an outer protein shell called a capsid and an inner core of nucleic acid ( either ribonucleic or dioxyribonucleic acid - RNA and DNA).
(iii)Viroid are the smallest infectious pathogen known. like some viruses ,Viroids are little more than a strand of genetic material called ribonucleic acid (RNA)
(iv)Bacterial virus( bacteriophage or phages have DNA or RNA as genetic material.
Hope it will help you..........