Bio 121 Chapter 12 (Final)

Growth at two replication forks arising from a single origin of replication produce a "bubble" as daughter DNA molecules form. T/F

TRUE

Telomerase is an enzyme that unwinds DNA during DNA replication. T/F

FALSE

A DNA molecule is considered antiparallel because the sugar-phosphate groups that are chained together to make each strand are oriented in opposite directions. T/F

TRUE

DNA replication is semiconservative because it uses one old strand as a template for the synthesis of a new strand. T/F

TRUE

Transfer RNA (tRNA) takes a message from DNA in the nucleus to the ribosomes in the cytoplasm. T/F

FALSE

During the replication of DNA, DNA polymerase has to synthesize the daughter strand in the 5' to 3' direction because DNA polymerase can only join nucleotides to the 3' end of the growing new strand. T/F

TRUE

Ribozymes are RNA molecules that function as enzymes, catalyzing reactions during RNA splicing. T/F

TRUE

Determine the number of codon sequences it would require to produce the following amino acid sequence: alanine - proline - serine - isoleucine - stop. A) It would take 5 codon sequences. B) It would take 3 codon sequences. C) It would take 6 codon sequences. D) It would take 4 codon sequences.

A

During the elongation of a polypeptide chain, ________ occurs when the mRNA moves to the next site on the ribosome to read the next codon. A) translocation B) transcription C) translation D) transference

A

For translation to take place, which of the following does NOT need to be present? A) DNA B) mRNA C) tRNA-amino acid complex D) rRNA E) ribosome

A

Match the following proteins to their function in DNA replication: unwinds DNA and separates parental strands A. DNA helicase B. DNA primase C. single- stranded binding protien D. DNA ligase E. DNA polymerase

A

One of Chargaff's rules states that A) A = T and G = C. B) A = C and T = G. C) A = G and T = C. D) A = T + G + C.

A

Which is NOT true about the genetic code? A) Most amino acids have only one codon. B) It is composed of triplet codes. C) Each codon consists of three bases. D) The groundwork for cracking the code began with the use of synthetic RNA. E) It contains start and stop codons as instructions.

A

Which of the following amino acid chains would be produced from the mRNA sequence AUA-CUU-CCU-AGU-UGA? A) Isoleucine - leucine - proline - serine - stop B) Isoleucine - leucine - stop - proline - serine C) Glycine - glutamate - lysine - lysine - stop D) Isoleucine - alanine - proline - serine - stop

A

Which of the following polypeptide chains would be sequenced from the mRNA code AGG-GAG-CCC? A) arginine - glutamate - proline B) serine - leucine - proline C) arginine - glutamate - alanine D) serine - aspartate - proline

A

Which of the following statements applies to the semiconservative nature of DNA replication? A) The old strands serve as a template for the new strand. B) The old strand is pulled apart and reformed into the new strand. C) The new strand serves as a template for the old strand. D) None of these statements apply to the semiconservative nature of DNA replication.

A

Which section of the pre-mRNA contains the protein-coding regions? A) exons B) introns C) The entire pre-mRNA contains protein-coding regions. D) The pre-mRNA does not code for proteins at all.

A

Why was the X-ray diffraction photography of Rosalind Franklin and Maurice Wilkins considered critical evidence in the study of DNA? A) The photographs indicated that DNA has a double helix structure. B) The photographs showed equal numbers of purines and pyrimidines. C) The photographs showed the bases of DNA were held together by hydrogen bonds. D) The photographs revealed the structure of the deoxyribose sugar. E) The photographs showed the location of each adenine, guanine, cytosine, and thymine.

A

Transcription of a DNA molecule with a nucleotide sequence of AAA-CAA-CTT results in an mRNA molecule with the complementary sequence of A) GGG-AGA-ACC. B) UUU-CUU-CAA. C) UUU-GUU-GAA. D) TTT-GAA-GCC. E) CCC-ACC-TCC.

C

A(n) ________ is a group of three bases on tRNA that is complementary to a specific mRNA codon. A) codon B) anticodon C) poly-A tail D) cap

B

Approximately how many base pairs are improperly matched before being repaired by the DNA polymerase? A) 1 in 10,000 B) 1 in 100,000 C) 1 in 1,000,000 D) 1 in 10,000,000 E) 1 in a billion

B

DNA replication is considered semiconservative because A) it will create three new identical strands when finished. B) it uses one old strand as a template for the synthesis of a new strand. C) it always replicates in the 3' to 5' prime direction. D) it never replicates in the 5' to 3' prime direction.

B

During DNA replication, the enzyme ________ catalyzes the elongation of new DNA strands. A) helicase B) DNA polymerase C) DNA ligase D) ATP synthase

B

If a DNA sample contains 13% adenine, what percentage of the sample contains cytosine? A) 13% B) 37% C) 26% D) 74%

B

If one strand of DNA has the base sequence AAG-CAA, the complementary strand has which of the following sequences? A) UUC-GUU B) TTC-GTT C) AAG-CAA D) UTC-GTU E) TTC-GTG

B

In the Watson and Crick model of DNA, the "steps" of the ladder are composed of A) sugars. B) a purine and a pyrimidine. C) two purines. D) two pyrimidines. E) a sugar and a phosphate molecule.

B

Match the following proteins to their function in DNA replication: places short pieces of RNA on the DNA strands to be replicated A. DNA helicase B. DNA primase C. single- stranded binding protien D. DNA ligase E. DNA polymerase

B

Scientists have created genetically modified organisms (GMOs) by isolating and then transferring the jellyfish gene for green fluorescent protein into pigs, bacteria, plants, and mice. The result was bioluminescent organisms! These experiments demonstrate that A) jellyfish genes may be transferred into other aquatic ectotherms, but not mammals. B) genes have no difficulty crossing the species barrier. C) animal genes from one species will not function if transferred into other animals. D) genes can only be transferred to other organisms within the same species.

B

Which of the following statements about DNA replication is NOT correct? A) Unwinding of the DNA molecule occurs as hydrogen bonds break. B) Replication occurs as each base is paired with another exactly like it. C) The process is known as semiconservative replication because one old strand is conserved in the new molecule. D) The enzyme that catalyzes DNA replication is DNA polymerase. E) Complementary base pairs are held together with hydrogen bonds.

B

Which of the following statements is NOT true about the debate over the nature of genetic material? A) Many scientists believed that DNA was not the genetic material because, with only four types of nucleotides, DNA did not have enough variability to store information. B) Scientists focused on carbohydrate and protein in their studies of possible genetic material since they knew that genes were on chromosomes and that chromosomes were made of carbohydrate and protein. C) Many scientists thought that proteins had a greater capacity for storing information because proteins contain 20 amino acids that could be sequenced differently. D) Some scientists thought that RNA was likely to be the genetic material.

B

Which of the following would be transcribed into mRNA? A) a noncoding gene B) a protein-coding gene C) a promoter D) a ribozyme

B

Transcription begins when A) initiation factors assemble ribosomal subunits, mRNA, and initiator tRNA. B) RNA polymerase comes to a stop sequence. C) RNA polymerase binds to a region of DNA called the promoter. D) new nucleotides are added to an existing strand of nucleotides.

C

Which of the following statements are true about DNA replication in eukaryotes? Select all that apply. A) Replication of the entire genome takes about ten minutes. B) A replication fork occurs at each growing point of the replicating chromosome(s). C) Eukaryotes have many different chromosomes, with replication occurring in each at the same time. D) Replication occurs at the rate of about 500-5000 base pairs per minute. E) Multiple sites of replication are present on each chromosome.

B, C, D, E

What properties must a substance possess in order to serve as the genetic material? Select all that apply. A) It must consist of many different types of subunits in order to code for the large variety of characteristics of a living organism. B) It must be able to store information that pertains to the development,structure, and metabolic activities of the cell or organism. C) It must be stable, so that it can be replicated with high accuracy during cell division and be transmitted from generation to generation. D) It must be able to catalyze chemical reactions at very high speeds in order to direct the metabolic activities of the cell. E) It must be able to undergo rare changes, called mutations, that provide the genetic variability required for evolution to occur.

B, C, E

You come across an article on alien nucleic acid structure. The article states that researchers have discovered a new single-ring nucleotide. Based on your knowledge of nucleic acids here on Earth, which of the following characteristics might apply to this new nucleotide? Select all that apply. A) The new nucleotide is probably a purine. B) The new nucleotide is probably a pyramidine. C) The new nucleotide may be similar to cytosine. D) The new nucleotide may be similar to guanine. E) The new nucleotide may be similar to uracil.

B, C, E

Which of the following items relate specifically to purines? Select all that apply. A) nucleotides with a single ring B) adenine C) cytosine D) nucleotides with a double ring E) guanine

B, D, E

An unknown chemical is analyzed and found to contain the bases thymine and guanine. This chemical is most likely A) tRNA. B) mRNA. C) DNA. D) rRNA.

C

DNA was shown to be the transforming substance when only the ________ enzymes could inhibit transformation. A) proteinase B) RNAase C) DNAase D) lipase

C

Match the following proteins to their function in DNA replication: attach to newly separated DNA and prevent it from re-forming the helix so replication can occur. A. DNA helicase B. DNA primase C. single- stranded binding protien D. DNA ligase E. DNA polymerase

C

The first codon to be deciphered was ________, which codes for ________. A) AAA; proline B) GGG; alanine C) UUU; phenylalanine D) TTT; arginine E) CCC; glycine

C

Which statement is NOT true about DNA replication? A) It proceeds in a 5'-to-3' direction only. B) One strand of new DNA is replicated faster than the other strand at the replication fork. C) DNA can only replicate at one point on a chromosome at one time. D) It occurs more rapidly in bacteria than in eukaryotes. E) DNA replication is considered semiconservative because there is always an old strand acting as a template for a new strand.

C

Approximately how many base pairs are still improperly matched in the bacterial genome after the DNA polymerase proofreads the DNA strand? A) 1 in 10,000 B) 1 in 100,000 C) 1 in 1,000,000 D) 1 in 100,000,000 E) 1 in a billion

D

Before Watson and Crick described DNA structure, Linus Pauling proposed a possible model with three strands of support running down the middle and the bases extending out the sides. How did Pauling's model differ from Watson and Crick's? A) Pauling proposed three support strands while Watson and Crick proposed two strands. B) Pauling proposed the support strands ran down the middle of the molecule while Watson and Crick proposed the support strands ran down the sides. C) Pauling proposed that the bases stick out the sides of the molecule while Watson and Crick proposed the bases were paired in the middle. D) All of the choices describe how Pauling's model was different than Watson and Crick's model.

D

Codons A) are each comprised of a triplet of nucleotides. B) are unambiguous. C) provide the instructions for synthesizing proteins. D) All of the choices are correct.

D

Match the following proteins to their function in DNA replication: binds Okazaki fragments together A. DNA helicase B. DNA primase C. single- stranded binding protien D. DNA ligase E. DNA polymerase

D

Nucleotides contain all of the following except A) a phosphate group. B) a 5-carbon sugar. C) a nitrogen base. D) histones.

D

Transformation of bacteria was shown to occur when ________ bacteria were injected into mice and the mice ________. A) live S strain; died B) live R strain; didn't die C) live S and R strain; died D) live R strain and dead S strain; died E) live S strain and dead R strain; didn't die

D

In order to help firmly establish DNA as the genetic material, Hershey and Chase performed an experiment using viruses and mice. T/F

FALSE

In order to help firmly establish DNA as the genetic material, Hershey and Chase radioactively tagged viral protein in one experiment and radioactively tagged viral RNA in the other experiment. T/F

FALSE

All of the following are associated with translation EXCEPT A) Growth of a polypeptide chain. B) Attachment of a ribosome to mRNA. C) Binding of two tRNA molecules per ribosome. D) Liberation of polypeptide from the ribosome. E) Production of mRNA.

E

Match the following proteins to their function in DNA replication: synthesizes and proofreads DNA strand A. DNA helicase B. DNA primase C. single- stranded binding protien D. DNA ligase E. DNA polymerase

E

The correct sequence of events in translation is A) initiation, termination, elongation. B) elongation, termination, initiation. C) termination, elongation, initiation. D) elongation, initiation, termination. E) initiation, elongation, termination

E

Which of the following statements concerning ribosomes are true? A) Several ribosomes are often attached to and translating the same mRNA. B) Ribosomes join amino acids to form a polypeptide. C) Ribosomes have a binding site for mRNA and three binding sites for tRNA molecules. D) No protein synthesis within a cell would occur without ribosomes. E) All of the above statements are true.

E

Which statement is NOT true about DNA replication in prokaryotes? A) Replication begins at a single origin of replication. B) Replication is bidirectional from the origin(s). C) Replication occurs at about 1 million base pairs per minute. D) Since bacterial cells replicate so rapidly, a second round of replication may begin before the first has been completed. E) There are many bacterial chromosomes, with replication occurring in each at the same time.

E

In order for a new nucleotide to be joined to a growing nucleic acid, it must be linked to the phosphate group on the 5' end of the previous nucleotide. T/F

FALSE