A) It is a polymer made up of a string of amino acids.
B) Each different sequence folds into a different three-dimensional shape.
C) The two strands of a DNA molecule are held together by base pairing.
D) It contains nitrogenous bases known as A, C, G, and U.
14) The size of the mouse (M. musculus) genome is 2700 megabases (Mb) and it contains about 25,000 genes arranged on 40 chromosomes. If the genes are evenly distributed on chromosomes in the mouse, what is the average number of genes per chromosome?
A) 1
B) 9.3
C) 67.5
D) 625
15) Which statement about the structure of proteins is false?
A) Proteins are made of long strings of 20 different common amino acids in different orders.
B) The order of amino acids in a polypeptide determines the three-dimensional shape of the folded molecule.
C) The chemical properties of each amino acid are determined by the amino acid's side chain.
D) Most proteins consist of two amino acid polymers attached together by hydrogen bonding.
16) Which is a structural feature shared by DNA, RNA, and proteins?
A) The order of monomers is important for function.
B) Each sequence of monomers folds into a different three-dimensional shape.
C) Each molecule is a polymer of four different nucleotides.
D) Two strands of monomers are connected by hydrogen bonding.
17) A segment of a protein has the amino acid sequence Ser—Gly—Leu. Is it possible to infer the sequence of the RNA that encodes this amino acid sequence?
A) Yes, the sequence is UCU—GGA—CUC.
B) Yes, the sequence is TCT—GGA—CTC.
C) No; more than one type of RNA (more than one base sequence) could encode this amino acid sequence.
D) No; the sequence of bases in RNA is not related to the amino acid sequence.
18) A sequence of bases in the middle of an RNA used to encode a polypeptide has the sequence UUA—AUG—CGU. Is it possible to infer the sequence of the amino acids encoded by this RNA?
A) Yes, the sequence is Leu—Met—Arg.
B) Yes, the sequence is Asn—Tyr—Ala.
C) No, this RNA sequence could encode more than one amino acid sequence.
D) No; the sequence of amino acids in polypeptides is not related to the sequence of bases in RNA.
19) Mutation of a mouse gene results in mice that lack heart muscle. What characteristic would you expect to find in a human gene that has a common origin with this mouse gene?
A) The DNA sequence of the human gene will be identical to the DNA sequence of the mouse gene.
B) The human and mouse genes will specify proteins with similar amino acid sequences.
C) The human and mouse genes will specify unrelated sequences of amino acids, but both proteins will function to prevent the formation of heart muscle.
D) The human and mouse genes will specify unrelated sequences of amino acids, and the human gene will not be involved in heart muscle formation.
20) A mouse gene was identified and determined to be required for formation of heart muscle. A gene with a similar sequence was identified in the human genome. What experiment could scientists do to determine if the mouse and human genes have similar functions?
A) The scientist could search the human genome for genes that encode proteins that are identical to the protein encoded by the mouse gene.
B) The scientist could place the normal human gene into normal mice and see if the resulting mice are viable.
C) The scientist could place the normal human gene into mutant mice to see if heart muscle forms in the mouse.
D) The scientist could place the mutant mouse gene into humans to see if humans develop without heart muscle.
21) A sequence of amino acids found in a subunit of the ATP synthase enzyme in several species is shown below. Which amino acids are likely to be most important to the function of ATP synthase?
A) Those that are shaded dark blue because the amino acids are identical between species.
B) Those that are shaded light blue because the amino acids are similar, but not identical.
C) Those that are not shaded because the amino acid sequences are different between species.
D) Comparing sequence between species does not indicate which amino acids are important to function.