Biology

6. The biological process of copying DNA so a cell can divide; produces two identical DNA molecules from one.
7. A sequence of three mRNA nucleotides that encodes a single amino acid or a stop signal during translation.
8. The process by which unspecialized cells become specialized in structure and function.
14. A three‑nucleotide sequence on tRNA that is complementary to an mRNA codon and ensures correct amino acid placement.
16. The process of making an RNA copy of a DNA sequence (gene) using RNA polymerase.
17. A DNA sequence upstream of a gene where RNA polymerase and transcription factors bind to initiate transcription.
18. A cluster of prokaryotic genes under control of a single promoter and operator, transcribed together as one mRNA.

1. A chain of amino acids linked by peptide bonds; one or more polypeptides fold to form a functional protein.
2. Repetitive DNA sequences at the ends of linear chromosomes that protect coding DNA and shorten with each cell division.
3. A heritable change in the nucleotide sequence of DNA.
4. A change in a cell’s genotype and phenotype caused when it takes up foreign DNA from its environment.
5. A virus that infects and replicates within bacteria.
9. A coding sequence within a gene that remains in mRNA after splicing and is translated into protein.
10. The process by which ribosomes read mRNA codons to assemble a polypeptide chain from amino acids.
11. A DNA regulatory sequence in an operon where a repressor protein can bind to block transcription.
12. A noncoding sequence within a eukaryotic gene that is transcribed into RNA but removed by splicing.
13. A condition in which an organism has more than two complete sets of chromosomes (e.g., triploid, tetraploid).
15. An agent (chemical, physical, or biological) that increases the frequency of mutations.