Masting Bio Chapter 17

In eukaryotic cells, transcription cannot begin until: -the two DNA strands have completely separated and exposed the promoter. -DNA nucleases have isolated the transcription unit. -several transcription factors have bound to the promoter. -the DNA introns are removed from the template. -the 59 caps are removed from the mRNA.

Which of the following is not true of a codon? -It never codes for more than one amino acid. -It is the basic unit of the genetic code. -It extends from one end of a tRNA molecule. -It consists of three nucleotides. -It may code for the same amino acid as another codon.

The anticodon of a particular tRNA molecule is: -catalytic, making the tRNA a ribozyme. -changeable, depending on the amino acid that attaches to the tRNA. -complementary to the corresponding mRNA codon. -complementary to the corresponding triplet in rRNA. -the part of tRNA that bonds to a specific amino acid.

Which of the following is not true of RNA processing? -Nucleotides may be added at both ends of the RNA. -RNA splicing can be catalyzed by spliceosomes. -Exons are cut out before mRNA leaves the nucleus. -A primary transcript is often much longer than the final RNA molecule that leaves the nucleus. -Ribozymes may function in RNA splicing.

Which component is not directly involved in translation? GTP Mrna DNA tRNA ribosomes

Which of the following mutations would be most likely to have a harmful effect on an organism? -a deletion of three nucleotides near the middle of a gene -a nucleotide-pair substitution -a single nucleotide deletion in the middle of an intron -a single nucleotide insertion downstream of, and close to, the start of the coding sequence -a single nucleotide deletion near the end of the coding sequence