Question

what is the best description of the structure of a chromosome in the nucleus of a non - dividing cell?
two long dna molecules wound around each other, associated with many proteins.
two long dna molecules wound around each other, with no proteins.
one long dna molecule, associated with many proteins.
one long dna molecule, with no proteins.

Explanation:

In a non - dividing cell nucleus, a chromosome consists of one long DNA molecule associated with many proteins (such as histones) which help in packaging and regulating DNA. There are not two long DNA molecules in a non - dividing cell's chromosome structure, and DNA is always associated with proteins in the nucleus.

Answer:

One long DNA molecule, associated with many proteins.