Biology Exam Quiz Review Questions

Amino acids with hydrophobic R groups are most often found in the interior of folded proteins. A) True B) False

A) True

Some amino acids are specified by just one codon, whereas others are specified by multiple codons. A) True B) False

A) True

Deoxyribonucleic acid is used for: (select all that apply) A) transmission of information B) storage of information C) biological catalysis D) energy storage E) cell-to-cell communication

A) transmission of information B) storage of information

RNA polymerase complex can do which actions? Select all that apply a) separate DNA strands b) release a finished RNA transcript from a DNA template c) allow RNA-DNA hybrids to form d) restore the original DNA strands

All of the Above

Transcription is sometimes described as a process in which RNA is "copied" from the template strand of DNA. This statement is potentially misleading because: Select all that apply a) the RNA transcript has a complementary sequence of bases to the template strand b) the RNA transcript and the DNA template strand are antiparallel c) RNA molecules contain uracil instead of thymine d) RNA nucleotides contain ribose and so cannot be an exact copy of DNA

All of the above

Which of the following statements about DNA is (are) correct? Select all that apply A) Adenine is complementary to cytosine B) Successive nucleotides are attached by peptide bonds C) There are 10 base pairs per turn in a helical DNA molecule D) The strands in DNA wrap around each other in a helix that coils to the right E) DNA typically exists in cells as a double helix

C, D, and E

In a solution that has pH = 7.0, the ratio of protons (H+) to hydroxide ions (OH-) equals a) 1 b) 1/70 c) 70 d) 1/7 e) 7

a) 1

Which of the following is true of DNA? a) A purine always forms a complementary base pair with a pyrimidine. b) A phosphate group in a nucleotide is attached to the 3′ carbon in ribose. c) Successive nucleotides in a strand are connected by hydrogen bonds. d) The percentage of the purine A always equals the percentage of the purine G. e) It is used by ribosomes for translation

a) A purine always forms a complementary base pair with a pyrimidine.

Which step occurs in the A site of the ribosome during translation? a) An incoming charged tRNA binds to this site. b) The tRNA carrying the growing polypeptide moves to this site as the ribosome slides to the next codon. c) An uncharged tRNA is ejected from this site as the ribosome slides to the next codon.

a) An incoming charged tRNA binds to this site.

Which step occurs in the E site of the ribosome during translation? a) An uncharged tRNA is ejected from this site as the ribosome slides to the next codon. b) The tRNA carrying the growing polypeptide moves to this site as the ribosome slides to the next codon. c) An incoming charged tRNA binds to this site.

a) An uncharged tRNA is ejected from this site as the ribosome slides to the next codon.

Examples of amino acids with hydrophobic R-groups include (Check all that apply) a) Phenylalanine b) Valine c) Lysine d) Arginine e) Leucine

a) Phenylalanine b) Valine e) Leucine

Transcription continues until: a) a terminator sequence is encountered. b) all bases in the DNA are copied. c) a ribosome pulls RNA polymerase off the DNA. d) a transcription factor signals the end of the gene. e) a stop codon is encountered.

a) a terminator sequence is encountered.

An intron is: a) an RNA sequence that is removed during the processing of an RNA molecule in the nucleus b) part of an intact, mature mRNA that leaves the nucleus. c) part of an RNA transcript that is not present in the DNA template d) a type of transfer RNA. e) a polypeptide that is excised out of a larger protein post-translationally

a) an RNA sequence that is removed during the processing of an RNA molecule in the nucleus

Which choice correctly lists the five most abundant elements found in living organisms? a) carbon, hydrogen, oxygen, nitrogen, phosphorus b) carbon, hydrogen, oxygen, nitrogen, iron c) magnesium, carbon, hydrogen, oxygen, nitrogen d) sodium, carbon, oxygen, nitrogen, phosphorus

a) carbon, hydrogen, oxygen, nitrogen, phosphorus

In transcription, the energy to attach each successive ribonucleotide to the growing RNA chain comes from: a) cleavage of the high-energy phosphate bonds of the incoming nucleotide. b) cleavage of the high-energy phosphate bonds of the growing transcript. c) cleavage of the 2′ hydroxyl group on the ribose of the incoming nucleotide. d) the RNA polymerase itself

a) cleavage of the high-energy phosphate bonds of the incoming nucleotide.

A pair of atoms joined by a polar covalent bond: a) has a slight positive charge on one atom and a slight negative charge on the other. b) mixes well with non-polar solvents. c) is unlikely to form hydrogen bonds with water d) has the charge spread evenly across both atoms.

a) has a slight positive charge on one atom and a slight negative charge on the other.

Which bonds rely on the attraction of positive and negative charges? Select all that apply: a) ionic bonds b) covalent bonds c) hydrogen bonds

a) ionic bonds and c) hydrogen bonds

In a double-stranded DNA molecule, the strands are said to be antiparallel because a) one strand runs 5' to 3' and the other 3' to 5' b) they wind around one another c) they form an uneven pair of grooves on the outside of molecule d) each purine of one strand pairs with a pyrimidine of another

a) one strand runs 5' to 3' and the other 3' to 5'

In double-stranded DNA, the amount of A equals that of T and the amount of C equals that of G because: a) the strands have complementary sequences of bases. b) the strands wind around one another c) pyrimidines always pair with each other, as do purines d) one strand runs 5' to 3' and the other 3' to 5'

a) the strands have complementary sequences of bases.

In the DNA of certain bacterial cells, 16% of the nucleotides are adenine. What are the percentages of the other nucleotides in the bacterial DNA? a) 34% thymidine, 16% guanine, 34% cytosine b) 16% thymidine, 34% guanine, 34% cytosine c) 34% uracil, 16% guanine, 16% cytosine d) 34% thymidine, 34% guanine, 16% cytosine

b) 16% thymidine, 34% guanine, 34% cytosine

A template DNA strand contains 30% A, 20% T, 27% G, and 23% C. The RNA transcript contains: a) 30% A, 20% U, 27% G, and 23% C. b) 30% U, 20% A, 27% C, and 23% G. c) 30% T, 20% A, 27% C, and 23% G d) 30% A, 20% T, 27% G, and 23% C

b) 30% U, 20% A, 27% C, and 23% G.

RNA processing consists of the: a) addition of a cap. b) All of these choices are correct. c) addition of a poly(A) sequence. d) removal of introns.

b) All of these choices are correct.

Muscle cells make different proteins than nerve cells because they have different sequences of DNA a) TRUE b) FALSE

b) FALSE

Which step occurs in the P site of the ribosome during translation? a) An incoming charged tRNA binds to this site. b) The tRNA carrying the growing polypeptide moves to this site as the ribosome slides to the next codon. c) An uncharged tRNA is ejected from this site as the ribosome slides to the next codon.

b) The tRNA carrying the growing polypeptide moves to this site as the ribosome slides to the next codon.

The association of individual water molecules with other water molecules is called _____ and occurs through _____ bonds between water molecules a) adhesion; polar covalent b) cohesion; hydrogen c) cohesion; polar covalent d) adhesion; hydrogen

b) cohesion; hydrogen

In the process of transcription, the RNA transcript is synthesized: a) from the 3′ end to the 5′ end. b) from the 5′ end to the 3′ end

b) from the 5′ end to the 3′ end

A template DNA strand contains the sequence 5′-ATGCTGAC-3′. The corresponding sequence in the RNA transcript is: a) 5′-UACGACUG-3′ b) 5′-TACGACTG-3′. c) 5′-GUCAGCAU-3′. d) 5′-GTCAGCAT-3′.

c) 5′-GUCAGCAU-3′.

Why did scientists many years ago believe that protein was the storage molecule for genetic information instead of DNA? a) There are more building blocks for protein than there are for DNA. b) Proteins carry out a great range of cellular functions c) All of these choices are correct d) Proteins have a wider variety of three-dimensional shapes than DNA

c) All of these choices are correct

Two of the main ingredients in plant fertilizer are phosphorus and nitrogen. These elements are found in which classes of biomolecules? a) lipids and carbohydrates b) carbohydrates and DNA c) DNA and proteins d) proteins and carbohydrates

c) DNA and proteins

A mutation takes place in a protein‑coding gene that changes one codon resulting in a single amino acid replacement. Which type of replacement is least likely to result in a disruption of protein structure and function? a) a hydrophobic amino acid to a hydrophilic amino acid b) a polar amino acid to a hydrophobic amino acid c) a polar amino acid to a polar amino acid d) a hydrophilic amino acid to a hydrophobic amino acid

c) a polar amino acid to a polar amino acid

An exon is: a) a protein that is modified post-translationally b) a transfer RNA that binds to the codon c) part of an intact, mature mRNA that leaves the nucleus. d) RNA that is removed during the processing of an RNA molecule and remains inside the nucleu e) a series of amino acids at the end of a new polypeptide that directs transcription to the ER

c) part of an intact, mature mRNA that leaves the nucleus.

Which choice correctly pairs the particles in an atom with its electrical charge? a) proton-negatively charged; neutron-uncharged; electron-negatively charged b) proton-uncharged; neutron-uncharged; electron-negatively charged c) proton-positively charged; neutron-uncharged; electron-negatively charged d) proton-positively charged; neutron-negatively charged; electron-negatively charged

c) proton-positively charged; neutron-uncharged; electron-negatively charged

When a peptide bond is created between two amino acids: a) the amino group of the first amino acid is joined to the carboxyl group of the second. b) the amino group of the first amino acid is joined to the amino group of the second. c) the carboxyl group of the first amino acid is joined to the amino group of the second. d) the carboxyl group of the first amino acid is joined to the carboxyl group of the second.

c) the carboxyl group of the first amino acid is joined to the amino group of the second.

READ CAREFULLY: Which choice most accurately describes the ratio of oxygen to carbon to hydrogen in a simple 6-carbon sugar such as glucose? a) 1:3:2 b) 1:2:1 c) 1:2:3 d) 1:1:2 e) 2:1:1

d) 1:1:2

In a nucleotide, the phosphate is attached to the _______ carbon of the sugar, and the base is attached to the carbon of the sugar a) 1'; 5' b) 3'; 5' c) 2'; 3' d) 5'; 1' e) 5'; 3'

d) 5'; 1'

Assuming that transcription and translation both proceed from left to right, which is the correct orientation of the DNA template, the RNA transcript, and the protein product? a) DNA template 5′- ......... -3′ RNA transcript 3′- ......... -5′ Protein product HOOC-......... -NH2 b) DNA template 3′- ......... -5′ RNA transcript 5′- ......... -3′ Protein product HOOC-......... -NH2 c) DNA template 5′- ......... -3′ RNA transcript 5′- ......... -3′ Protein product H2N-......... -COOH d) DNA template 3′- ......... -5′ RNA transcript 5′- ......... -3′ Protein product H2N- ......... -COOH

d) DNA template 3′- ......... -5′ RNA transcript 5′- ......... -3′ Protein product H2N- ......... -COOH

You obtain three samples of nucleic acid and would like to determine each sample's chemical identity (single-stranded or double-stranded DNA or RNA). You analyze the base composition of each sample and get the results shown in the table above, with the numbers indicating percentage of each base in the strand. What can you conclude from these results? a) Sample 1 is single-stranded DNA, sample 2 is RNA, and sample 3 is double-stranded DNA. b) Both samples 1 and 3 are single-stranded DNA, and sample 2 is RNA. c) Sample 1 is double-stranded DNA, sample 2 is single-stranded DNA, and sample 3 is RNA. d) Sample 1 is double-stranded DNA, sample 2 is RNA, and sample 3 is single-stranded DNA. e) Sample 1 is RNA, sample 2 is double-stranded DNA, and sample 3 is single-stranded DNA

d) Sample 1 is double-stranded DNA, sample 2 is RNA, and sample 3 is single-stranded DNA.

A mutation takes place in a protein‑coding gene that changes one codon resulting in a single amino acid replacement. Which type of replacement is most likely to result in a disruption of protein structure and function? a) a hydrophobic amino acid to a hydrophobic amino acid b) a polar amino acid to an acidic amino acid c) a polar amino acid to a basic amino acid d) a hydrophobic amino acid to a hydrophilic amino acid

d) a hydrophobic amino acid to a hydrophilic amino acid

Alternative splicing allows for: a) increased stability of a mature mRNA b) multiple genes to be used to code for a single polypeptide chain c) enhanced recognition of an mRNA by a ribosome. d) different polypeptides to be made from a single gene

d) different polypeptides to be made from a single gene

The oxygen and hydrogens of a water molecule contains what type of bond? a) van der Waals interactions b) ionic c) hydrogen d) polar covalent

d) polar covalent

When a mixture of debris from killed virulent bacteria and live nonvirulent bacteria are injected into mice: a) half the mice are killed, and the other half survive. b) the mice survive because none of the living bacteria are virulent. c) the mice survive for a period of a few weeks and then die from an unrelated illness. d) the mice are killed because the nonvirulent bacteria are transformed into virulent bacteria e) the mice are killed because the virulent bacteria are revived

d) the mice are killed because the nonvirulent bacteria are transformed into virulent bacteria

A _______ substance could contain __________ bonds which allow it to interact with water a) hydrophobic; hydrogen b) hydrophilic; hydrogen c) hydrophilic; non-polar covalent d) hydrophobic; non-polar covalent e) hydrophilic; polar covalent

e) hydrophilic; polar covalent