Answer:
a. Codons and anticodons are both related to the genetic code. A codon is a sequence of three nucleotides in DNA or RNA that corresponds to a specific amino acid. An anticodon is a sequence of three nucleotides in tRNA that is complementary to a codon in mRNA.
b. mRNA, tRNA, and rRNA are three types of RNA that play key roles in protein synthesis. mRNA carries the genetic information from DNA to the ribosome, where it is translated into protein. tRNA delivers the correct amino acids to the ribosome based on the codon sequence in the mRNA. rRNA makes up the ribosome itself, where protein synthesis occurs.
c. Promoters are DNA sequences that signal the start of a gene and the direction in which it is transcribed. Operators are regulatory sequences that control the expression of genes by binding to repressor proteins. Operons are groups of genes that are controlled by a single promoter and operator. Repressors are proteins that can bind to the operator to prevent transcription of the operon.
d. Exons and introns are regions of DNA that makeup genes. Exons are the coding regions of a gene that contain information for making a protein. In contrast, introns are non-coding regions of DNA that are transcribed into RNA but are removed during the process of splicing. Splicing involves the removal of introns and the joining together of exons to form a mature mRNA molecule that can be translated into protein.