What are the different categories of exotoxins, and how do they function?
What will be an ideal response?
Answer: The three categories are AB toxins, cytolytic toxins, and superantigen toxins. The cytolytic toxins work by degrading cytoplasmic membrane integrity causing lysis. The superantigens work by stimulating large numbers of immune cells resulting in extensive inflammation and tissue damage. The AB toxins bind to host cell surface receptors and damage the cell when the A subunit is transferred across the targeted cytoplasmic membrane by the B subunit.
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Microarrays can be used to detect which one of the following? (Choose all that apply)
A. single nucleotide polymorphisms B. copy number variation C. restriction fragment length polymorphisms D. variable number tandem repeats
Mutations in the DFNA20/26 locus, which codes for the actin gamma 1 protein, are associated with congenital deafness. An irate senator complains that government money is being wasted on studies of this mutant gene -- in yeast! "I am no biologist," says the senator, "but I am pretty sure yeast don't have ears." How do you respond?
A. "You are right, Senator -- yeast do not have ears. We should revoke the funding immediately." B. "We can learn valuable information about the structure of the mutant protein by expressing it in yeast. It is difficult to collect large amounts of actin from tiny hair cells, and unethical to collect it from human patients." C. "We can learn valuable information about the transcription of the mutant gene in yeast. It is much more difficult to study transcription in human cells." D. "We can learn valuable information about sound transmission through the mutant yeast. By placing a speaker against a yeast vial and recording sound from the other side, we can infer how the mutant actin affects sound waves." Clarify Question What is the key concept addressed by the question? What type of thinking is required? Gather Content What do you already know about mutant genes? What other information is related to the question? Choose Answer Given what you now know, what information is most likely to produce the correct answer? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
One of the generalizations of cell theory is that ____
a. all living organisms are made up of cells b. all cells divide by meiosis c. all cells have a nucleus d. cells arise through spontaneous generation e. growth is solely the result of cell division
Which one of the following is true regarding viruses?
a) Virions contain both DNA and RNA. b) They multiply by binary fission. c) They are sensitive to antibiotics. d) They are not composed of cells.