ON A TEST
Viral infections are difficult to treat medically because: (a) viruses do not respond to treatment with antibiotics (b) viruses have smaller ribosomes than the host cell (c) the symptoms of infection are always of short duration (d) viruses never elicit a response of antibody attack by the body's immune system

(a) viruses do not respond to treatment with antibiotics

lesson summarykaryotypes a genome is the full set of all the genetic information that an organism carries in its dna. chromosomes arebundles of dna and protein found in the nucleus of a eukaryotic cell.

the correct answer is option d.

an appositive is a noun, noun phrase or noun clause which follows another noun or noun phrase in order to describe it or name it another way. they are usually used between commas, brackets or dashes.

the example sentence with the correct use of commas is the following:

her uncle, the man over there in the red shirt, owns the hardware store in town.