| The non-coding sequences of a gene or pre-mRNA are ____. |
aromatic |
| A ____ is a regulatory sequence upstream (5') of a gene. |
helicase |
| Purines have two ____ rings, whereas pyrimidines have one. |
histones |
| A mutation can be an insertion, deletion, or ____ of nucleotides. |
introns |
| The primary structure of DNA is its ____ sequence. |
mutation |
| During replication, ____ separates the DNA strands. |
nucleotide |
| A change in the sequence of a chromosome is a ____. |
promoter |
| In chromatin, DNA is spooled around proteins called ____. |
substitution |
