NEET BIOLOGY

Detailed explanation-1: -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-2: -Most viruses vary in diameter from 20 nanometres (nm; 0.0000008 inch) to 250–400 nm; the largest, however, measure about 500 nm in diameter and are about 700–1, 000 nm in length. Only the largest and most complex viruses can be seen under the light microscope at the highest resolution.

Detailed explanation-3: -Mimivirus is the largest and most complex virus known. Is it an evolutionary bridge between nonliving viruses and living organisms, or is it just an anomaly? Viruses are small and fairly simple.

Detailed explanation-4: -AAV is the smallest DNA virus with an average size of 20 nm. AAV was discovered in 1965 as a defective contaminating virus in an adenovirus stock (Atchison et al., 1965).