Copying of the information in DNA into mRNA, which can leave the nucleus, is called

A. a segment of DNA that carries the instructions for one protein:A gene is a functional unit of DNA that contains the necessary coding sequence to produce a specific protein. It includes exons, which code for amino acids, and regulatory regions that control expression.

B. a strand of introns only:Introns are non-coding segments within a gene that are removed during RNA processing. A gene is not composed solely of introns, as it also contains exons that determine protein structure.

C. an RNA messenger that codes for a particular polypeptide:Messenger RNA is the transcript produced from a gene. While it carries the code for a protein, the gene itself is the DNA sequence, not the RNA product.

D. a three-base triplet that specifies a particular amino acid:A three-base triplet is a codon in mRNA, which specifies a single amino acid during translation. A gene consists of many codons and encompasses the full sequence necessary for the entire protein.

True:Vellus hair is soft, fine, and lightly pigmented, covering much of the body surface. It is most noticeable in children and adult females, where it serves a protective function without providing significant insulation.