MCB 2010C Microbiology REAL Exam 2VERIFIED WITH ACTUAL SOLUTION 100%

Are Viruses Living or Nonliving? They are only considered living when they are inside of a host cell, using their resources and energy. Outside of a host they are considered intert. When are Viruses considered to be "alive"? When they are inside of a host cell. When inside, their nucleic acid (ONLY RNA OR DNA) become active. *Virus replicates Obligatory Intracellular Parasites Require livinghost cell in order to multiply - Such as Viruses. Defining a Virus 1) Contains 1 Nucleic Acid (DNA or RNA) 2) Protein coat surrounds the DNA or RNA 3)Multiply within host using host machinery ---because they don't have the ways of making/obtaining their own nutrients. like ATP or enzymes. Virus Characteristics *Some are enclosed by an envelope which consists of lipids, proteins, carbohydrates *some have spikes *only infect the cells of ONE host. Host Range The spectrum of host cells that a virus can infect. -invertebrates -vertebrates -plants -protist -fungi -bacteria The virus must be able to attach to a the particular host's cell.