AP BIOLOGY

Detailed explanation-1: -In the lytic cycle, the virus attaches to the host cell and injects its DNA. Using the host’s cellular metabolism, the viral DNA begins to replicate and form proteins. Then fully formed viruses assemble. These viruses break, or lyse, the cell and spread to other cells to continue the cycle.

Detailed explanation-2: -Retroviruses, such as the human immunodeficiency virus type 1, and orthomyxoviruses, such as influenza A virus, are RNA viruses that also deliver their genomes into the nucleus of the cells they infect.

Detailed explanation-3: -All enveloped viruses contain fusion proteins, which are the molecules responsible for fusing the envelope to a cellular membrane. These proteins are derived from the virion’s genetic sequence.

Detailed explanation-4: -They replicate only within cells of the host that they infect. Indeed, unlike any microorganism, many viruses can, in suitable cells, reproduce themselves from their genome, a single nucleic acid molecule; i.e., their nucleic acid alone is infectious.

Detailed explanation-5: -Viruses cannot replicate on their own, but rather depend on their host cell’s protein synthesis pathways to reproduce. This typically occurs by the virus inserting its genetic material in host cells, co-opting the proteins to create viral replicates, until the cell bursts from the high volume of new viral particles.