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Biology help part 2 please!?

• Question 14 Marks: 1 A virus infects a cell and randomly inserts many short segments of DNA containing a stop codon throughout the organism's chromosomes. This will probably cause _____. Choose one answer. a. manufactured proteins to be short and defective b. the DNA to break up into thousands of short segments c. incorrect pairing between mRNA codons and amino acids d. no bad effects, as long as the stop codons are not also inserted into tRNA e. all of the above Question 15 Marks: 1 The structures called snRNPs are _____. Choose one answer. a. part of a spliceosome b. involved in the removal of exons from DNA c. a type of specialized carbohydrate d. a critical component of the initiation complex e. all of the above Question 16 Marks: 1 In a eukaryotic cell, transcription takes place _____. Choose one answer. a. on the cell membrane b. in the rough endoplasmic reticulum c. in the cytoplasm d. on free ribosomes e. in the nucleus Question 17 Marks: 1 In eukaryotes, which of the following mechanisms of gene regulation operates after transcription, but before translation of mRNA into protein?
      
  Choose one answer. a. RNA splicing b. DNA packaging into nucleosomes c. action of repressors and activators d. protein degradation e. all of the above Question 18 Marks: 1 Bacteria can transcribe and translate human genes to produce functional human proteins because _____. Choose one answer. a. the genetic code is universal b. bacterial ribosomes and eukaryotic ribosomes are identical c. eukaryotes do not really need a nucleus d. RNA has catalytic properties e. bacterial and eukaryotic RNA polymerases are identical Question 19 Marks: 1 Polysomes may be defined as _____. Choose one answer. a. microfilaments and microtubules b. groups of lysosomes c. groups of ribosomes d. groups of chromosomes e. groups of peroxisomes Question 20 Marks: 1   During the transcription of a given portion of a DNA molecule _____. Choose one answer. a. mRNA is synthesized on both chains of the DNA molecule at once b. mRNA is synthesized on both chains of the DNA molecule, but first on one side and then the other c. mRNA is synthesized on only one of the chains d. half of the mRNA is synthesized on half of one chain; then the other half of the mRNA is made on the other half of the DNA e. Any of the above patterns may be found. Question 21 Marks: 1 When RNA is being made, the RNA base _____ always pairs with the base _____ in DNA. Choose one answer. a. U;T b. T;G c. U;A d. A;U e. T;A Question 22 Marks: 1 A cell biologist found that two different proteins with largely different structures were translated from two different mRNAs. These mRNAs, however, were transcribed from the same template within the cell nucleus. Which mechanism below could best account for this? Choose one answer. a. Different systems of DNA unpacking could result in two different mRNAs. b. A point mutation might have altered the gene. c. Exons from the same gene could be spliced in different ways to make different mRNAs. d. Different transcription factors were involved in the transcription of the two mRNAs. e. The two proteins have different functions in the cell. Question 23 Marks: 1  Nuclei of eukaryotic cells contain spliceosomes that are made up of _____. Choose one answer. a. snRNA b. snRNA and tRNA c. snRNA and DNA d. snRNA and protein e. DNA and protein Question 24 Marks: 1 In transcription, _____. Choose one answer. a. the promoter region acts as an initial binding site for RNA polymerase b. only one of the DNA strands is used as the template c. the RNA nucleotides used are produced by the cell d. all of the above e. none of the above Question 25 Marks: 1 Cells are able to distinguish proteins destined for secretion or for segregation to specific intracellular compartments from those that will remain in the cytoplasm because _____. Choose one answer. a. there are two types of ribosomes: one group that synthesizes cytoplasmic proteins only, and another type that synthesizes secreted or compartment-specific proteins only b. some proteins, as they begin to be synthesized, contain a signal region that causes the ribosome with its growing polypeptide to attach to the ER and translocate the polypeptide into the lumen (space) of the ER c. proteins destined for secretion or for a specific compartment are all synthesized in the nucleus, whereas cytoplasmic proteins are all synthesized in the cytoplasm d. each compartment in the cell (the nucleus, lysosome, and so forth) has its own set of ribosomes that synthesize proteins unique to that compartment e. ribosomes contain two types of subunits

• Answer:

  A,A,E,A,A,C,C,C,C,D,D, B