Viruses don't exist

How did the first person to see a virus know that it was a virus without any references as to what a virus looks like?

How do viruses find their host if they have no legs, arms, eyes, ears, brains, sense of touch or means of locomotion?

During the lytic cycle of virulent phage, the bacteriophage takes over the cell, reproduces new phages, and destroys the cell. T-even phage is a good example of a well-characterized class of virulent phages. There are five stages in the bacteriophage lytic cycle (see Figure 1). Attachment is the first stage in the infection process in which the phage interacts with specific bacterial surface receptors (e.g., lipopolysaccharides and OmpC protein on host surfaces). Most phages have a narrow host range and may infect one species of bacteria or one strain within a species. This unique recognition can be exploited for targeted treatment of bacterial infection by phage therapy or for phage typing to identify unique bacterial subspecies or strains. The second stage of infection is entry or penetration. This occurs through contraction of the tail sheath, which acts like a hypodermic needle to inject the viral genome through the cell wall and membrane. The phage head and remaining components remain outside the bacteria.

This figure outlines the stages of the lytic cycle.

Step 1 is attachment when the phage attaches to the surface of the host. The bacteriophage is shown sitting on the surface of the bacterial host cell.
Step 2 is penetration when the viral DNA enters the host cell. The image shows DNA from within the virus being injected into the host DNA.

Step 3 is biosynthesis when the phage DNA replicates and the phage proteins are made.

Step 4 is maturation when the new phage particles are assembled. This shows the viral components being put together in the cell.

Step 5 is lysis when the cell lyses and the newly made phages are released. This shows the cell bursting and built viruses being released. A virulent phage shows only the lytic cycle pictured here. In the lytic cycle, the phage replicates and lyses the host cell.

The third stage of infection is biosynthesis of new viral components. After entering the host cell, the virus synthesizes virus-encoded endonucleases to degrade the bacterial chromosome. It then hijacks the host cell to replicate, transcribe, and translate the necessary viral components (capsomeres, sheath, base plates, tail fibers, and viral enzymes) for the assembly of new viruses. Polymerase genes are usually expressed early in the cycle, while capsid and tail proteins are expressed later. During the maturation phase, new virions are created. To liberate free phages, the bacterial cell wall is disrupted by phage proteins such as holin or lysozyme. The final stage is release. Mature viruses burst out of the host cell in a process called lysis and the progeny viruses are liberated into the environment to infect new cells.

In a lysogenic cycle, the phage genome also enters the cell through attachment and penetration. A prime example of a phage with this type of life cycle is the lambda phage. During the lysogenic cycle, instead of killing the host, the phage genome integrates into the bacterial chromosome and becomes part of the host. The integrated phage genome is called a prophage. A bacterial host with a prophage is called a lysogen. The process in which a bacterium is infected by a temperate phage is called lysogeny. It is typical of temperate phages to be latent or inactive within the cell. As the bacterium replicates its chromosome, it also replicates the phage’s DNA and passes it on to new daughter cells during reproduction. The presence of the phage may alter the phenotype of the bacterium, since it can bring in extra genes (e.g., toxin genes that can increase bacterial virulence). This change in the host phenotype is called lysogenic conversion or phage conversion. Some bacteria, such as Vibrio cholerae and Clostridium botulinum, are less virulent in the absence of the prophage. The phages infecting these bacteria carry the toxin genes in their genome and enhance the virulence of the host when the toxin genes are expressed. In the case of V. cholera, phage encoded toxin can cause severe diarrhea; in C. botulinum, the toxin can cause paralysis. During lysogeny, the prophage will persist in the host chromosome until induction, which results in the excision of the viral genome from the host chromosome. After induction has occurred the temperate phage can proceed through a lytic cycle and then undergo lysogeny in a newly infected cell.

The sequence of events that occurs when you come down with the flu or a cold is a good demonstration of how a virus works:

1. An infected person sneezes near you.
   
2. You inhale the virus particle, and it attaches to cells lining the sinuses in your nose.
   
3. The virus attacks the cells lining the sinuses and rapidly reproduces new viruses.
   
4. The host cells break, and new viruses spread into your bloodstream and also into your lungs. Because you have lost cells lining your sinuses, fluid can flow into your nasal passages and give you a runny nose.
   
5. Viruses in the fluid that drips down your throat attack the cells lining your throat and give you a sore throat.
   
6. Viruses in your bloodstream can attack muscle cells and cause you to have muscle aches.
   

3. How can something that is dead, suddenly come to life?

4. How can viruses survive in the atmosphere and sunlight without any walls for protection? (very fragile)

5. How does a entity (virus) that kills its host pass on its genes and what does it gain by killing the host?

6. If viruses are proteins, then why don't small insects like ants find them and eat them all?

The Discovery of the Virus was done by Process of Elimination, not Direct Observation.

How do viruses find their host if they have no legs, arms, eyes, ears, brains, sense of touch or means of locomotion?

Pro is conceding that they can exist, and is merely asking me to clarify some specifics here.

Question 1: What makes viruses end up infecting one type of host-cell per type of virus?

Question 2: How do they do that and even move if they have no limbs or nerve-based senses?

Overall, viruses are NOT land 'animals' so to speak. They are much more fish-like in their operations. They move via fluid carrying them around and explore the cells, hoping to find one matching their Capsid-protein configuration.

They move via fluid carrying them around and explore the cells, hoping to find one matching their Capsid-protein configuration.

3. How can something that is dead, suddenly come to life?

4. How can viruses survive in the atmosphere and sunlight without any walls for protection? (very fragile)

5. How does a entity (virus) that kills its host pass on its genes and what does it gain by killing the host?

6. If viruses are proteins, then why don't small insects like ants find them and eat them all?

'They just do/don't' is literally the overall answer-mechanism to these. Please expand on why we should have speculation here and why that would lead us to conclude they don't exist (rather than that they exist and that we have yet to work these out). I will counter these either by explaining the answer or explaining why we don't know yet.