Question

___________ are an exception to cell theory.
A. Bacteria
B. Fungi
C. Virus
D. Lichen

Answer 1

Cell is the structural, functional, biologic unit of all organisms, the cell is the basic unit of life, and cells are also called as building blocks of life, and the study of cells is called cell biology or cytology. It contains the fundamental molecule of life, of which all living things are composed.

Complete answer:
History
Cells were discovered in 1665 by Robert Hooke.
Cell theory was developed in the year 1839 by Matthias Jakob Schleiden.
The three tenets to the cell theory are given below:
All living organisms are composed of one or more cells.
The cell is the basic unit of structure, function, and organization in organisms.
Cells arise from a pre-existing cell.
From the above-given theory, the first point is not valid or not acceptable for virus
Virus violates cell theory
Because viruses are not made up of any cells, and these viruses do not affect cells in any process, so viruses are not related to cell theory.
A virus is nothing but a protein coat, which surrounds DNA or RNA.
Those virus can adapt to the environment and respond to the stimuli, and they do not use any energy to grow, so virus is exception for cell theory
Normal Components of cell
The components of the cell are enveloped by a membrane called plasma membrane or biological membrane, which controls in and out the movement of particles and maintains the electric potential.
Most of the cell volume is made up of cytoplasm.
Both prokaryotes and eukaryotes consist of cell organelles, whereas in prokaryotes, they are very simple and not bound by a membrane.
The nucleus of prokaryotes is made of either DNA or RNA.
In eukaryotes, the nucleus consists of chromosomes, and the synthesis of DNA and RNA takes place in the nucleus only and enveloped by a nuclear membrane.
It consists of organelles like mitochondria, Golgi apparatus, endoplasmic reticulum, Mitochondria, peroxisomes, Lysosomes, chloroplast, etc.
Cells are multiplied either by mitosis or meiosis.
From the given explanation of cell theory, the virus is the answer.

Note: In higher organisms like humans, all cells are mainly categorized into 4 types, which are epithelial cells, Nerve cells, muscle cells, and Connective tissue cells. Whereas the human body is totally made up of 40 trillion number of cells, out of which the human brain includes the 80 billion cells. But this type of organization is absent in viruses.