Exam 11: DNA Biology and Technology

A) heterochromatin
B) intron
C) exon
D) euchromatin
E) nucleosome

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A) replication.
B) translation.
C) transcription.
D) transformation.
E) base pairing.

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A) transcription activators are required for RNA polymerase binding, while transcription factors slow RNA polymerase binding.
B) transcription activators accelerate transcription, while transcription factors assist RNA polymerase binding.
C) transcription activators slow transcription, while transcription factors accelerate transcription.
D) transcription factors prevent RNA polymerase binding, while transcription activators assist RNA polymerase binding.
E) transcription factors are required for RNA polymerase binding, while transcription activators accelerate transcription. Transcription factors are proteins that are required for RNA polymerase to bind to a promoter. RNA polymerase can bind a promoter and transcribe a gene when transcription activators are not present, but their presence accelerates the process when they bind DNA and promote transcription.

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A) rRNA
B) tRNA
C) mRNA
D) DNA
E) protein In translation, the anticodon of a tRNA carrying an amino acid hydrogen bonds with the codon on the mRNA. Thus, tRNA acts as an adaptor to enable the cell to read the genetic code contained within the mRNA.

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A) normal replication, but gaps remain in the sugar-phosphate DNA backbone.
B) failure to remove introns from the primary mRNA.
C) incompletely processed primary mRNA that does not get translated properly.
D) translation to initiate normally but fail to proceed to elongation.
E) DNA strands to separate normally but fail to join nucleotides in the growing nucleotide chain. DNA ligase is needed during DNA replication to seal breaks in the sugar-phosphate backbone after DNA polymerase joins nucleotides into a new chain. If it is defective, all other processes may occur normally, but there will be gaps remaining in the sugar-phosphate DNA backbone when DNA replication occurs.

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A) 2
B) 4
C) 8
D) 16
E) 64 There are four possible bases that could occur in each position, so this means that there are 4², or sixteen, possible combinations of these four bases that could occur.

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A) one of the two resulting DNA molecules is new.
B) the two resulting DNA molecules each have one new DNA strand and one old strand from the original DNA molecule.
C) both of the resulting DNA molecules are composed of new strands of nucleotides.
D) no extra nucleotides are incorporated into the replicated DNA molecules.
E) the sequence of nucleotides in one strand is conserved, whereas the new DNA molecule consists of a unique sequence of nucleotides. At the end of replication, each new DNA molecule contains one old DNA strand and one new DNA strand. The old strand was used as a template to build the new strand.

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A) chemical binds to receptor, signal transduction pathway stimulates transcription activator, target gene is transcribed and translated
B) signal transduction pathway stimulates receptor, transcription activator is activated by target gene
C) chemical binds to receptor, target gene is transcribed and translated, signal transduction pathway stimulates proteins that bring about desired changes
D) signal transduction pathway activates receptor, chemical binds to receptor, target gene stimulates transcription activator
E) chemical binds to receptor, signal transduction pathway stimulates target gene, target gene stimulates transcription activator Signal transduction pathways are initiated by the binding of a chemical signal by a receptor, which initiates the pathway. The pathway usually ends with the stimulation of a transcription activator, which brings about the needed response in the cell by causing the transcription of needed genes.

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A) cytosine
B) uracil
C) thymine
D) adenine
E) guanine In RNA, uracil replaces thymine.

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A) compacting the chromatin of one of their X chromosomes allows them to inactivate it and produce the same amount of gene product as a male.
B) unpacking one of their X chromosomes allows them to produce more gene product than a male.
C) compacting the chromatin in one of their X chromosomes allows them to conserve histone proteins.
D) compacting the chromatin in one of their X chromosomes allows them to produce more gene product than a male from the other X chromosome.
E) unpacking one of their X chromosomes allows them to choose which allele they wish to express, which a male cannot do. Barr bodies are formed because otherwise, a female would produce twice as much gene product as a male from genes on the X chromosome, and too much of some gene products can be harmful.

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A) is helical.
B) has a repeated pattern.
C) is both helical and has a repeated pattern.
D) contains beta sheets arranged in a repeated pattern.
E) contains alpha helices and beta sheets. Rosalind Franklin's DNA diffraction data demonstrated that it is helical, from the X pattern in the center, and that it is repeated over and over, from the dark portions at the top and bottom edges. James Watson and Francis Crick incorporated Franklin and Chargaff's work into their description of the structure of DNA.

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A) ensures that all amino acids are represented at least once by the code.
B) ensures that other organisms can read the code too.
C) ensures that DNA can replicate properly.
D) prevents the wrong amino acid from being incorporated into a protein.
E) prevents early termination of transcription.

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A) DNA to DNA to protein
B) mRNA to DNA to protein
C) DNA to mRNA to protein
D) DNA to tRNA to mRNA to protein
E) DNA to rRNA to protein Information contained within genes is transcribed into mRNA. The information contained within the mRNA is then translated by a ribosome into a protein.

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A) Barr bodies are still present.
B) histones still block the binding of RNA polymerase to the promoter.
C) euchromatin is always transcriptionally inactive.
D) transcription factors still block the binding of RNA polymerase to the promoter.
E) heterochromatin contains DNA with accessible promoters. Even euchromatin is inaccessible unless the nucleosomes are moved to make the promoter accessible to RNA polymerase.

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A) mRNA; DNA
B) DNA; mRNA
C) DNA; tRNA
D) mRNA; tRNA
E) mRNA; rRNA Transcription and DNA replication are separate processes. Transcription transfers the information contained within DNA into an mRNA, while DNA replication simply copies the information into another DNA molecule.

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