AP BIOLOGY

Detailed explanation-1: -Viruses are ultramicroscopic because they range in size from 2 mm to 450 mm. A specific animal virus has the ability to attach to and enter almost any animal host cell. Viruses are the most common cause of acute infections that do not result in hospitalization. Viruses are simple, noncellular, and lack mRNA.

Detailed explanation-2: -A virus is conventionally defined as an ultramicroscopic particle of organic matter that can only multiply with the help of a cell. Viruses that multiply inside bacteria (non-nucleated cells or prokaryotes) are called bacteriophages.

Detailed explanation-3: -Viruses are generally ultramicroscopic, typically from 20 nm to 900 nm in length. Some large viruses have been found. Virions are acellular and consist of a nucleic acid, DNA or RNA, but not both, surrounded by a protein capsid.

Detailed explanation-4: -Virus and cell size comparison. Human viruses can vary in size but are generally in the range of 20–200 nm in diameter. In comparison, bacteria are generally 2–3 M in length, and an average human cell is 10–30 M.

Detailed explanation-5: -Size of virus particles commonly is determined three ways: (1) Electronmicroscopy (2) Ultrafiltration and (3) Ultracentrifugation. and density gradient ultracentrifugation to determine size of a virus believed to be one cause of Infectious Bovine Keratitis (IBK). cells.