Question 1

Which of the following statements concerning ribosomes are true?

Accepted Answer

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. 
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

Question 2

While many body cells only replicate 40 to 60 times,cells that produce certain white blood cells may replicate many more times.It is,therefore,crucial that proofreading and repair occur so that the transfer of biological information is accurate.On the other hand,absolute accuracy in replication of biological information would cancel out mutations that are the raw material of evolution.Why is accuracy in transcription and translation less critical than accuracy in gene replication?

Accepted Answer

A mutation in a gene will be passed down to future generations of the cell and,in some instances,to future generations of organisms.If the mutation is detrimental,then all cells and/or organisms receiving the mutation will be adversely affected.If errors occur in transcription and translation,the gene product (protein)may be altered and may even be nonfunctional.If the DNA is unaltered,however,with the next occurrence of transcription and translation,the protein would be normal.Therefore,the effect of errors in transcription and translation are limited to that particular event and not to future generations.Each gene can make many mRNAs which can make many proteins,so errors in a single mRNA or protein don't generally matter very much.

Question 3

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

Accepted Answer

A) True 
 B)False  True

Question 4

Transformation of bacteria was shown to occur when ________ bacteria were injected into mice and the mice ________.

Accepted Answer

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 
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

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

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

Accepted Answer

A) True 
 B)False

Question 7

Why was the X-ray diffraction photography of Rosalind Franklin and Maurice Wilkins considered critical evidence in the study of DNA?

Accepted Answer

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) 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.

Question 8

Which statement is NOT true about DNA replication?

Accepted Answer

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. 
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.

Question 9

Which is NOT true about the genetic code?

Accepted Answer

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) 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.

Question 10

Which of the following items relate specifically to purines? Select all that apply.

Accepted Answer

A) nucleotides with a single ring 
B) adenine 
C) cytosine 
D) nucleotides with a double ring 
E) guanine 
A) nucleotides with a single ring 
B) adenine 
C) cytosine 
D) nucleotides with a double ring 
E) guanine

Question 11

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.

Accepted Answer

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. 
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.

Question 12

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

Accepted Answer

A) True 
 B)False

Question 13

Transcription begins when

Accepted Answer

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. 
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.

Question 14

During the elongation of a polypeptide chain,________ occurs when the mRNA moves to the next site on the ribosome to read the next codon.

Accepted Answer

A) translocation 
B) transcription 
C) translation 
D) transference 
A) translocation 
B) transcription 
C) translation 
D) transference

Question 15

What properties must a substance possess in order to serve as the genetic material? Select all that apply.

Accepted Answer

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. 
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.

Question 16

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.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following polypeptide chains would be sequenced from the mRNA code AGG-GAG-CCC?

Accepted Answer

A) arginine - glutamate - proline 
B) serine - leucine - proline 
C) arginine - glutamate - alanine 
D) serine - aspartate - proline 
A) arginine - glutamate - proline 
B) serine - leucine - proline 
C) arginine - glutamate - alanine 
D) serine - aspartate - proline

Question 18

For translation to take place,which of the following does NOT need to be present?

Accepted Answer

A) DNA 
B) mRNA 
C) tRNA-amino acid complex 
D) rRNA 
E) ribosome 
A) DNA 
B) mRNA 
C) tRNA-amino acid complex 
D) rRNA 
E) ribosome

Question 19

According to Watson and Crick's model,DNA consists of two strands of nucleotides that are antiparallel.What does this mean? What evidence supports the antiparallel nature of the strands?

Accepted Answer

Answers may vary.DNA consists of two str

Question 20

Which section of the pre-mRNA contains the protein-coding regions?

Accepted Answer

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) exons 
B) introns 
C) The entire pre-mRNA contains protein-coding regions. 
D) The pre-mRNA does not code for proteins at all.

Exam 12: Molecular Biology of the Gene

Which of the following statements concerning ribosomes are true?

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

Transformation of bacteria was shown to occur when ________ bacteria were injected into mice and the mice ________.

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

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

Why was the X-ray diffraction photography of Rosalind Franklin and Maurice Wilkins considered critical evidence in the study of DNA?

Which statement is NOT true about DNA replication?

Which is NOT true about the genetic code?

Which of the following items relate specifically to purines? Select all that apply.

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

Transcription begins when

During the elongation of a polypeptide chain,________ occurs when the mRNA moves to the next site on the ribosome to read the next codon.

What properties must a substance possess in order to serve as the genetic material? Select all that apply.

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.

Which of the following polypeptide chains would be sequenced from the mRNA code AGG-GAG-CCC?

For translation to take place,which of the following does NOT need to be present?

According to Watson and Crick's model,DNA consists of two strands of nucleotides that are antiparallel.What does this mean? What evidence supports the antiparallel nature of the strands?

Which section of the pre-mRNA contains the protein-coding regions?

A View of Life

Basic Chemistry

The Chemistry of Organic Molecules

Cell Structure and Function

Membrane Structure and Function

Metabolism: Energy and Enzymes

Photosynthesis

Cellular Respiration

The Cell Cycle and Cellular Reproduction

Meiosis and Sexual Reproduction

Mendelian Patterns of Inheritance

Regulation of Gene Expression

Biotechnology and Genomics

Darwin and Evolution

How Populations Evolve

Speciation and Macroevolution

Origin and History of Life

Taxonomy,systematics,and Phylogeny

Viruses,bacteria,and Archaea

Protist Evolution and Diversity

Fungi Evolution and Diversity

Plant Evolution and Diversity

Flowering Plants: Structure and Organization

Flowering Plants: Nutrition and Transport

Flowering Plants: Control of Growth Responses

Flowering Plants: Reproduction

Invertebrate Evolution

Vertebrate Evolution

Human Evolution

Animal Organization and Homeostasis

Circulation and Cardiovascular Systems

The Lymphatic and Immune Systems

Digestive Systems and Nutrition

Respiratory Systems

Body Fluid Regulation and Excretory Systems

Neurons and Nervous Systems

Sense Organs

Locomotion and Support Systems

Hormones and Endocrine Systems

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Animal Development and Aging

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Transformation of bacteria was shown to occur when bacteria were injected into mice and the mice .