1. GENE REGULATION prokaryotic cells – have about 2,000 genes
human genome – has about 30,000

2. Prokaryotes – genes are usually an unbroken stretch of nucleotides that code for a protein
Eukaryotes – genes are interrupted by. . . introns – long segments of nucleotides that have no coding information.
exons - the portion of a gene that are translated or expressed into proteins.
After transcription the introns on the mRNA are cut or spliced, and the exons are then joined together and translated.

4. Evolutionary Advantage: by having introns and exons cells can occasionally shuffle exons between genes and make new genes.

5. Not all genes are transcribed and translated all of the time; this would waste the cell’s energy and materials. Cells, therefore, are able to regulate which genes are expressed and which are not depending on the cell’s needs.

6. 2
1. Which step below represents transcription? 2. Which step below represents translation? 3. Which step below represents DNA replication? 3 1
(Proteins)

7. Anticodons: AAU AUG GUC
5. What are the codons that correspond to the following segment of DNA? DNA: CAG TAT GAT 6. What are the anticodons that correspond to the following segment of mRNA codons? mRNA: UUA – UAC – CAG
Codons: GUC AUA CUA
Anticodons: AAU AUG GUC