Chapter 17 (Gene Expression) Concepts

The flow of information in a cell proceeds in what sequence?

from DNA to RNA to protein

A particular triplet of bases in the template strand of DNA is 5'-AAA-3'. The anticodon on the tRNA that binds the mRNA codon is ________.

3'-AAA-5'

Which of the following molecules is/are produced by translation? Include molecules that are subject to further modification after initial synthesis 1. Aminoacyl-tRNA synthetase 2. RNA polymerase 3. The amino acid glycine

Aminoacyl-tRNA synthetase, RNA polymerase

Which of the following processes correctly describes alternative RNA splicing? 1. It is a mechanism for increasing the rate of translation. 2. It increases the rate of transcription. 3. It can allow the production of similar proteins from different RNAs. 4. It can allow the production of proteins of different sizes and functions from a single mRNA.

It can allow the production of proteins of different sizes and functions from a single mRNA.

Which of the following statements about the function of RNA polymerase is correct? 1. It relies on other enzymes to unwind the double helix. 2. It unwinds the double helix and adds nucleotides to a growing strand of RNA. 3. It adds nucleotides to the 5′ end of the growing mRNA molecule. 4. It proceeds slowly along the DNA strand, requiring about a minute to add two nucleotides to the growing mRNA molecule. 5. All of the listed choices are correct.

It unwinds the double helix and adds nucleotides to a growing strand of RNA.

What best describes the redundancy in the genetic code?

More than one codon can specify the addition of the same amino acid.

The average length of a transcription unit along a eukaryotic DNA molecule is about 27,000 nucleotide pairs, whereas an averaged-sized protein is about 400 amino acids long. What is the best explanation for this fact?

Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that are not translated

If a bacteria contained a mutant aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA, what would occur?

Proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU.

Which of the following processes occurs as part of transcription? 1. proteins are synthesized 2. mRNA attaches to ribosomes 3. DNA is replicated 4. RNA is synthesized

RNA is synthesized

Which of the following molecules are produced by transcription? 1. Ribozymes 2. Messenger RNA 3. Ribosomal proteins

Ribozymes and mRNA

What is a ribozyme?

a biological catalyst made of RNA

Which of the following mutations would be most likely to have a harmful effect on an organism? 1. a deletion of three nucleotides near the middle of a gene 2. a single nucleotide deletion near the end of the coding sequence 3. a single nucleotide insertion downstream of, and close to, the start of the coding sequence 4. 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

Which of the following molecules carries information from DNA and directs incorporation of amino acids at the ribosome? 1. enzymes 2. tRNA 3. rRNA 4. mRNA

mRNA

Which molecules directly participate in the process of translation?

mRNA, tRNA, and rRNA

A codon consists of __________ bases and specifies which __________ will be inserted into the polypeptide chain.

three, amino acid