chapter 14 ap bio
The genetic code is essentially the same for all organisms. Based on this information, one can logically assume which of the following statements to be correct?
A gene from an organism can theoretically be expressed into the same protein by any other organism.
Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression?
A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end.
Which component is not directly involved in translation?
DNA
A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine then binds to the growing polypeptide on the other tRNA (#2) already in the ribosome. Where does tRNA #2 move to after this bonding of lysine to the polypeptide?
E site
Which of the following is not true of RNA processing?
Exons are cut out before mRNA leaves the nucleus.
Which of the following statements correctly describes alternative RNA splicing?
It can allow the production of proteins of different sizes and functions from a single gene or its pre-mRNA
The tRNA shown in Figure 14.5 has its 3' end projecting beyond its 5' end. What will occur at this 3' end?
The amino acid will bind covalently.
Which of the following statements is true about protein synthesis in prokaryotes?
Translation can begin while transcription is still in progress.
Figure 14.5 represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid?
UUC
Which of the following DNA mutations is likely to have the most negative effect on the protein it specifies?
a base-pair deletion
The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the most likely result of this mutation in the protein product?
a polypeptide missing one amino acid
What is a ribozyme?
an RNA with enzymatic activity
Accuracy in the translation of mRNA into the sequence of amino acids in a polypeptide depends on specificity in which of the following?
bonding of the anticodon to the codon and the attachment of amino acids to tRNAs
The anticodon of a particular tRNA molecule is
complementary to the corresponding mRNA codon.
A part of an mRNA molecule with the following sequence is being read by a ribosome: 5'-CCG-ACG-3' (mRNA). The charged transfer RNA molecules shown in Figure 14.4 (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. The dipeptide that will form will be
proline-threonine
Initiation of transcription in eukaryotes requires which of the following in addition to RNA polymerase?
several transcription factors attached to the promoter.
There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that
the rules for base pairing between the third base of a codon and tRNA are flexible.
