Bio Chapter 12 Questions

3) The anticodon for the codon AUC is ________.

UAG

5) A mutation in which one nucleotide in the DNA sequence is substituted for another nucleotide is referred to as a ________ mutation.

point

40) Suppose one strand of a 'mini-gene' has the base sequence TACCCGGATTCA. If we assume no introns are involved, how many amino acids does the polypeptide encoded by this gene have? A) 2 B) 4 C) 6 D) 12

B) 4

58) Which point mutation would be most likely to have a catastrophic effect? A) A base substitution B) A base deletion near the start of the coding sequence C) A base deletion near the end of the coding sequence D) The deletion of three bases near the start of the coding sequence E) A base insertion near the end of the coding sequence

B) A base deletion near the start of the coding sequence

26) Which of the following contains four types of nucleotides but no uracil? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

B) DNA

27) Which of the following has two polynucleotide strands? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

B) DNA

28) Which of the following contains deoxyribose? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

B) DNA

2) Imagine that the short DNA base sequence GGCTGC is transcribed and then translated by a ribosome. The following activated tRNA molecules are available in the cytoplasm: tRNA Anticodon: GGC CGU UGC CCG ACG CGG Amino Acid: proline alanine threonine glycine cysteine alanine What resulting dipeptide will form? A) Cysteine-alanine B) Proline-threonine C) Glycine-cysteine D) Alanine-alanine E) Threonine-glycine

B) Proline-threonine

34) Which statement correctly describes transcription? A) RNA chains of different genes can be transcribed from either DNA strand, with RNA polymerase traveling from the 5' end and moving toward the 3' end. B) RNA chains of different genes can be transcribed from either DNA strand, with RNA polymerase traveling from the 3' end and moving toward the 5' end. C) RNA chains of all genes are synthesized from the same DNA strand, with the growing RNA strand always starting at the 5' end and moving toward the 3' end. D) RNA chains of all genes are synthesized from the same DNA strand, with the growing RNA strand always starting at the 3' end and moving toward the 5' end.

B) RNA chains of different genes can be transcribed from either DNA strand, with RNA polymerase traveling from the 3' end and moving toward the 5' end.

62) A 'mini-gene' has the base sequence TACCCGTGCACG. Which of the following sequences represents a single base substitution? A) TACCCGTGCACG B) TACCCGAGCACG C) TACCCGGCACG D) TACCCGTGTCACG E) TACCGTGCTACG

B) TACCCGAGCACG

21) What is an anticodon? A) Four consecutive bases in tRNA B) Three consecutive bases in tRNA C) The beginning of a DNA molecule D) Three consecutive bases in mRNA E) Three consecutive amino acids in a protein

B) Three consecutive bases in tRNA

5) Which of the following is found in RNA but NOT in DNA? A) Adenine B) Uracil C) Thymine D) Phosphate groups E) Deoxyribose

B) Uracil

60) A gene can be mutated with no resulting functional change in the protein that is produced from that gene if A) the mutation alters the active site of an enzyme. B) a codon has changed, but it codes for the same amino acid as the original codon. C) an entire codon has been removed. D) RNA polymerase can edit the mutation from the mRNA produced during translation.

B) a codon has changed, but it codes for the same amino acid as the original codon.

18) The nitrogenous base uracil pairs with A) thymine. B) adenine. C) guanine. D) cytosine. E) uracil.

B) adenine.

1) The sequence of nitrogen-containing bases on one strand of DNA most directly determines the sequence of A) fatty acids in a fat molecule. B) amino acids in a protein molecule. C) sugars in a polysaccharide molecule. D) bases in a protein molecule.

B) amino acids in a protein molecule.

47) A tRNA molecule brings ________ to the ribosome during protein synthesis. A) mRNA B) an amino acid C) a polypeptide D) RNA polymerase

B) an amino acid

22) Transfer RNA A) is a nucleic acid that carries the code for the primary structure of a protein. B) brings amino acids to the ribosome. C) is a subunit of ribosomes. D) transfers proteins into the nucleus.

B) brings amino acids to the ribosome.

17) Which of the following molecules transfers information from the nucleus to the cytoplasm? A) DNA B) mRNA C) tRNA D) Proteins E) Lipids

B) mRNA

55) A gene mutation is defined as change in the A) nucleotide sequence of RNA. B) nucleotide sequence of DNA. C) activation of a gene. D) structure of ribosomes.

B) nucleotide sequence of DNA.

1) In the fungus Neurospora, a metabolic pathway synthesizes the amino acid Z (which is essential for its survival) from the precursor W. The intermediates X and Y are also produced in this pathway. The enzymes E1, E2, and E3 catalyze three reactions in the process, as follows: E1 E2 E3 W→X→Y→Z X-ray radiation can be used to create a mutant strain of Neurospora that has a defective gene sequence for E2. Based on this scenario, the mutant strain will survive on media that contain A) only W or X. B) only Y or Z. C) W, X, Y, or Z. D) only X. E) only Z.

B) only Y or Z.

31) A transcription start signal is called a(n) A) initiation codon. B) promoter. C) origin. D) start site. E) nonsense codon.

B) promoter.

25) Ribosomes are a collection of A) small proteins that function in translation. B) proteins and small RNAs that function in translation. C) proteins and tRNAs that function in transcription. D) proteins and mRNAs that function in translation. E) mRNAs and tRNAs that function in translation.

B) proteins and small RNAs that function in translation.

15) The genetic code is A) different in different organisms. B) read in sets of three bases called codons. C) used during the translation of DNA to mRNA. D) a set of two base sequences coding for each amino acid.

B) read in sets of three bases called codons.

12) If the sequence of bases in a section of DNA is TAGGCTAA, what is the corresponding sequence of bases in mRNA? A) ATCCGATT B) TAGGCTAA C) CGAAUCGG D) AATCGGAT E) AUCCGAUU

E) AUCCGAUU

65) Which of the following is NOT a means of regulating gene expression? A) Regulating how long a protein lasts in a cell B) Modifying proteins after they are synthesized C) Varying the rate at which messenger RNAs are translated D) Varying the rate at which messenger RNAs are transcribed E) Deleting genes from cells in which they are not needed

E) Deleting genes from cells in which they are not needed

50) Which of the following is a protein made up of amino acids? A) Uracil B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

E) RNA polymerase

53) Which of the following synthesizes RNA molecules in the nucleus? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

E) RNA polymerase

24) What is the anticodon for AUC? A) TAG B) AUC C) GAU D) CUA E) UAG

E) UAG

42) Suppose the template DNA strand of a 'mini-gene' has the base sequence TACCCGGATTCA. The anticodon of the tRNA that carries the first amino acid to the ribosome will be A) AUG. B) UAC. C) UCA. D) AGU. E) UAG.

E) UAG.

41) The manufacture of proteins from RNA and amino acids is referred to as A) activation. B) transformation. C) replication. D) transcription. E) translation.

E) translation.

68) Your tongue does not grow hair because A) different genes are expressed in different tissues. B) skin cells have extra DNA that codes for hair proteins. C) the genes for hair proteins have been deleted from the cells of your tongue. D) saliva prevents hair from growing.

A) different genes are expressed in different tissues.

3) The 'one-gene, one-enzyme' hypothesis concluded that A) each allele codes for a single type of protein. B) specific enzymes give rise to specific genes. C) only certain genes function in cells. D) enzymes regulate gene activity. E) DNA is transcribed into RNA, which is translated into protein.

A) each allele codes for a single type of protein.

14) Which of the following has the fewest nucleotides in its strand? A) mRNA, having 75 nucleotides B) mRNA, having 50 codons C) Protein, having 40 amino acids D) Protein, with 2 polypeptides, each having 35 amino acids E) mRNA, having 100 bases

A) mRNA, having 75 nucleotides

13) How many bases are in a codon? A) 3 B) 4 C) 20 D) 64

A) 3

7) How many consecutive mRNA bases are needed to specify an amino acid? A) 3 B) 4 C) 20 D) 64

A) 3

2) As seen in this figure, how many exons were used to assemble the pre-mRNA sequence, and how many exons were used in the finished mRNA? A) 3; 3 B) 3; 2 C) 5; 3 D) 6; 3

A) 3; 3

61) A 'mini-gene' has the base sequence TACCCGTGCACG. If the T at the beginning of the sequence is deleted, what will be the consequence? A) All of the codons after that point will be changed. B) Only the amino acid coded for in that codon will be changed. C) RNA polymerase will skip that codon, but all the others will be read normally. D) RNA polymerase will correct the deletion, and a normal protein will be produced. E) The first nucleotide is always replaced anyway, so there will be no change.

A) All of the codons after that point will be changed.

11) Which of the following molecules functions to transfer genetic information from one generation to the next? A) DNA B) mRNA C) tRNA D) Protein molecules E) Lipid molecules

A) DNA

19) How can RNA be distinguished from DNA? A) RNA is single-stranded. B) RNA lacks the base uracil. C) RNA does not contain a sugar. D) RNA is never found in the nucleus

A) RNA is single-stranded.

10) The genetic material of some viruses, such as HIV, is not DNA but is instead A) RNA. B) protein. C) carbohydrate. D) lipid.

A) RNA.

45) What molecule is responsible for translation of the four-letter 'nucleic acid language' (A, T, G, and C nucleotides) into the 20 'amino acid language' of proteins by bringing in amino acids to the ribosome? A) Transfer RNA B) Ribosomal RNA C) Messenger RNA D) DNA

A) Transfer RNA

66) The fact that calico cats are only female supports the theory of A) X-chromosome inactivation and Barr bodies in females. B) two X chromosomes being required for coat color in cats. C) testosterone inactivation of Y-chromosome genes. D) mutations in all genes on one X chromosome.

A) X-chromosome inactivation and Barr bodies in females.

46) A tRNA that carries a specific amino acid enters the protein-synthesizing machinery at the ribosomes and pairs with the appropriate A) codon. B) anticodon. C) charge. D) amino acid.

A) codon.

35) In eukaryotes, a promoter that signals the beginning of the gene typically consists of A) the bases TATAAA and response elements. B) rRNA and tRNA. C) the base sequence AUG and transcription factor binding sites. D) both DNA and RNA.

A) the bases TATAAA and response elements.

37) The process of converting the 'message' of mRNA into a sequence of amino acids is called A) translation. B) transcription. C) activation. D) replication. E) repression.

A) translation.

29) The function of the promoter is to signal the RNA polymerase A) where to start transcribing the DNA. B) which strand of the DNA to read. C) where to start translating the DNA. D) where to add the first amino acid to the protein.

A) where to start transcribing the DNA.

6) In females, an entire X chromosome is inactivated in each cell. The inactivated X chromosome is called the ________ ________.

Barr body

9) If a bacterial protein is made from 30 amino acids, how many nucleotides are needed to code for its production? A) 30 B) 60 C) 90 D) 120 E) 600

C) 90

33) Suppose one strand of a 'mini-gene' has the base sequence TACCCGGATTCA. The last codon in the mRNA sequence will be A) UGA. B) AGT. C) AGU. D) TCA.

C) AGU.

32) What does mRNA carry away from the nucleus? A) Enzymes B) Ribosomes C) Information D) Amino acids E) tRNA

C) Information

52) Which of the following contains codons? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

C) Messenger RNA

69) Which of the following is NOT a theory of epigenetics explaining how cells can change gene function without changing the DNA base sequence? A) Modification of DNA B) Modification of chromosomal proteins C) Mutations causing new beneficial alleles D) Altering transcription and translation with noncoding RNA

C) Mutations causing new beneficial alleles

59) What kind of mutation occurs when one base is changed to another at a single location in the DNA? A) Insertion B) Deletion C) Substitution D) Neutral

C) Substitution

44) In a wild-type strain of fruit flies, the length of a gene from the start to the stop codon is 2,000 DNA bases. Suppose an experiment indicated that the mRNA molecule transcribed from this gene is much shorter (only 1,200 bases). What is the most likely explanation for this? A) A mutation caused the formation of an extra stop codon in the gene. B) The mRNA was prematurely degraded. C) There are introns in the DNA that were cut out of the mRNA. D) The first 800 bases of DNA are always cut out as it is transcribed into mRNA.

C) There are introns in the DNA that were cut out of the mRNA.

1) Based on this table, which polypeptide would be synthesized from the mRNA base sequence AUGCCUGACUUA? A) phe-met-pro-leu B) met-pro-asp-tyr C) met-pro-asp-leu D) ile-pro-ala-tyr E) met-phe-glu-leu

C) met-pro-asp-leu

70) What is an advantage to an organism producing microRNA? A) microRNA can protect against heart disease and cancer. B) microRNA causes mutations in unused genes. C) microRNA can protect against viral infections. D) microRNA allows for the inactivation of Barr bodies.

C) microRNA can protect against viral infections.

54) A random change in a DNA nucleotide base sequence A) cannot have an influence on genetic variation. B) is never apparent in the organism. C) represents a mutation. D) is never beneficial to the organism. E) always kills the cell.

C) represents a mutation.

30) Transcription is the process of A) synthesizing a DNA molecule from an RNA template. B) assembling an RNA molecule without a template. C) synthesizing an RNA molecule using a DNA template. D) synthesizing a protein using information from mRNA. E) replicating a single-stranded DNA molecule.

C) synthesizing an RNA molecule using a DNA template.

23) The type of RNA that binds to a specific amino acid is A) messenger RNA. B) ribosomal RNA. C) transfer RNA. D) nuclear RNA.

C) transfer RNA.

8) What is the total number of different possible combinations of bases in a codon? A) 3 B) 4 C) 20 D) 64

D) 64

4) Which of the following is noted when comparing DNA and RNA? A) No sugar is present in either molecule. B) Hydrogen bonding is important only in DNA. C) Only DNA has a backbone made up of sugars and phosphates. D) Adenine pairs with different bases in DNA and RNA. E) Thymine pairs with different bases in DNA and RNA.

D) Adenine pairs with different bases in DNA and RNA.

36) Which of the following occurs in the nucleus? A) Transcription only B) Translation only C) Replication of genetic material only D) Both transcription and replication of genetic material E) Both translation and replication of genetic material

D) Both transcription and replication of genetic material

39) All of the following are directly involved in translation EXCEPT: A) ribosomes. B) tRNA. C) amino acids. D) DNA. E) mRNA.

D) DNA.

64) Which of the following is true regarding gene expression? A) Gene expression remains constant throughout an organism's life span. B) Different individuals of the same species express all of the same genes. C) Gene expression is not influenced by the environment. D) Different tissues within an organism express different genes.

D) Different tissues within an organism express different genes.

20) If a tRNA molecule that is specialized for the transfer of the amino acid valine has the anticodon CAG, it will couple with the codon A) GAC. B) GTC. C) TUG. D) GUC. E) CAG.

D) GUC.

38) What is the site of protein synthesis in the cell? A) Smooth endoplasmic reticulum B) Nucleus C) Nucleolus D) Ribosome E) Eukaryotic chromosome

D) Ribosome

67) How can a single gene code for more than one protein? A) Different RNA polymerases transcribe it and produce different proteins. B) Different types of ribosomes translate the resulting mRNA, producing different proteins. C) Different amino acid chains can be coded by the same mRNA. D) The exons within an mRNA can be spliced together in different ways.

D) The exons within an mRNA can be spliced together in different ways.

48) Which of the following attaches to specific amino acids? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

D) Transfer RNA

49) Which of the following has anticodons? A) Ribosomal RNA B) DNA C) Messenger RNA D) Transfer RNA E) RNA polymerase

D) Transfer RNA

51) Which of the following binds to codons? A) RNA polymerase B) DNA C) Messenger RNA D) Transfer RNA

D) Transfer RNA

43) A sequence of three RNA bases can function as a(n) A) codon only. B) anticodon only. C) gene only. D) codon or anticodon.

D) codon or anticodon.

6) Both DNA and RNA A) are single-stranded molecules. B) contain the same four types of nitrogen-containing bases. C) have the same five-carbon sugars. D) contain phosphate groups. E) cannot be present in a cell simultaneously.

D) contain phosphate groups.

57) A mutation that results in a change in the codon reading pattern could result from A) a base insertion only. B) a base deletion only. C) a base substitution only. D) either an insertion or a deletion of a base.

D) either an insertion or a deletion of a base.

56) For a mutation to affect the evolution of an animal species, it must occur within A) somatic cells. B) prokaryotic cells. C) diploid cells. D) gametes.

D) gametes.

2) The sequence of nitrogen-containing bases on one strand of DNA could determine all of the following EXCEPT the sequence of A) nitrogen-containing bases in mRNA. B) amino acids in a protein molecule. C) nitrogen-containing bases in the other DNA strand. D) ribose and phosphate molecules in tRNA.

D) ribose and phosphate molecules in tRNA.

63) 'Gene expression' is a term that relates to A) how genes are passed from parent to offspring. B) the unique set of genes in an individual. C) the karyotype of a chromosome set. D) the flow of genetic information from DNA to proteins. E) DNA replication.

D) the flow of genetic information from DNA to proteins.

16) The process of copying genetic information from DNA to RNA is called A) translation. B) transformation. C) replication. D) transcription.

D) transcription.

5) Each ribosome is specific for a particular type of protein. True or False?

false

6) tRNA is necessary for transcription to occur. True or False?

false

8) The Barr body is the X chromosome in the cell that is expressed, whereas the other X chromosome is inactivated. True or False?

false

4) A random change in the DNA nucleotide base sequence is called a ________.

mutation

1) The strand of the DNA molecule that is transcribed is called the ________ strand.

template

2) In eukaryotic cells, ________ occurs in the nucleus, resulting in the production of mRNA, which then travels to the ribosome for ________ into an amino acid chain.

transcription; translation

1) Messenger RNA is single-stranded. True or False?

true

2) In general, each gene codes for a specific protein. True or False?

true

3) A codon of mRNA consists of three bases that code for an amino acid. True or False?

true

4) The site of protein synthesis in the cytoplasm is the ribosome. True or False?

true

7) Steroid hormones have the ability to regulate transcription. True or False?

true