In electron micrographs of HSV infection, the intact virus initially reacts with cell-surface proteoglycans, then with specific receptors. This is later followed by viral capsids docking with nuclear pores. Afterward, the capsids go from being full to being "empty." Which of the following best fits these observations?A) The viral envelope mediates entry into the cell, the capsid mediates entry into the nuclear membrane, and the genome is all that enters the nucleus. B) Only the genetic material of the virus is involved in the cell's infectivity, and is injected like the genome of a phage. C) The viral capsid mediates entry into the cell, and only the genomic DNA enters the nucleus, where it may or may not replicate. D) The viral envelope is not required for infectivity, since the envelope does not enter the nucleus.

The correct answer is (A) The viral envelope mediates entry into the cell, the capsid mediates entry into the nuclear membrane and the genome is all that enters the nucleus.

Explanation:

The herpes simplex virus, or HSV, causes herpes. This virus affects the external genital, oral mucosa and other mucosal surfaces and skin in other parts of the body.They are of two types: HSV-1 and HSV-2 Enveloped herpes viruses enters the host cell via fusion between viral envelope and cell membrane of the host cell. Once inside the cell, the viral capsid is released into the nuclear membrane, where its degraded and releases the viral genome, which enters into the nucleus through the nuclear pore complex, where it is ready for its next stage, i.e for replication and transcription. Hence option A is correct.

it would lead to upper respiratory infections and pneumonia.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.