Which molecules do not normally cross the nuclear membrane? - Nucleotide triphosphates - Proteins - mRNA. - DNA

Answer : DNA is the molecule that normally doesnot cross the nuclear membrane.

Explanation:

The functioning of DNA is always from inside the nucleus and it does not needs to be transported anywhere for its functioning. Hence, DNA would be the molecule that will most likely never cross the nuclear membrane.

Rest all molecules like the gene regulatory proteins, mRNA, RNA processing proteins etc are selectively monitored and they pass in and out of the nuclear membrane.

The nuclear membrane can be described as a lipid bi-layer membrane which surrounds the nucleus and is only present in the eukaryotic cells. The DNA is properly packed inside the nucleus enclosed by the nuclear membrane.