Questions

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. Scientific theories are not ever proved in the sense of being proved to be 100% correct.

Examples of some scientific theories are ::

Evolution, gravity, atomic theory, the germ theory of disease, relativity, quantum theory, electromagnetic theory, layered Earth theory, etc...

The branch of biology that studies the different structures and functions of the cell is called Cell Biology or Cytology.

 A cell is the smallest unit of life that can replicate independently, and cells are often called the "building blocks of life"

Cell Biology deals with :

• Life cycle 

• Structure and organisation of cell organelles and their physiological properties. 

• Metabolic processes 

• Interactions with their environment 

• Signalling pathways.

Viruses are responsible for some of the most dangerous and deadly diseases including influenza, ebola, rabies and smallpox.

Despite their potential to kill, these potent pathogens are in fact considered to be non-living.

Reasons:

1. Viruses don't have any cells, like living organisms do. They have protein coats but no organelles or other cellular machinery. Just a little DNA packet.

2. Viruses can't produce new proteins, DNA, or RNA and therefore are unable to reproduce on their own. They need infected cells' machinery to make all of these and produce new virons.

3. Viruses have no metabolic activity. They don't use or convert energy and have no ongoing interior processes. They're basically just inert structures until they impact a potential host cell.