Final answer:
The incorrect statement about viruses is that all viruses are obligatory intercellular parasites. Viruses are actually obligate intracellular parasites, needing to be within host cells to replicate.
Step-by-step explanation:
The statement about viruses that is not true is b) All viruses are obligatory intercellular parasites. This statement is incorrect because viruses are obligate intracellular parasites, meaning they must enter the cells of a host organism to replicate; they cannot replicate between cells or outside of host cells. Let's address the truth in the other options briefly:
- a) All viruses are obligatory intracellular parasites. - This is true as viruses require host cells to replicate.
- c) Viruses occur in a wide variety of very different shapes, sizes and constructions. - This is true; viruses can have helical, polyhedral, or complex shapes.
- d) A viral host may be a plant, an animal or a bacterial cell. - This is true; viruses can infect a wide range of host organisms, including plants, animals, and bacteria.
- e) Viral genetic material can be either RNA or DNA. - This is also true; viruses can have either RNA or DNA as their genetic material.
Option b) All viruses are obligatory intercellular parasites. should be disregarded as it misrepresents the nature of viral replication.