Animal extracellular matrices contain each of the following except
A) collagens.
B) proteoglycans.
C) pectins.
D) fibronectins.
E) elastins.
Answer: C
You might also like to view...
Place the steps of biofilm formation in the correct order. _____ Surface (substratum) is preconditioned by environmental molecules. _____ Quorum sensing and the establishment of the extracellular matrix commences as microbes attach more stably. _____ Biofilm matures and some microorganisms escape to the planktonic state. _____ Microbes attach and detach from the preconditioned surface.
Fill in the blank(s) with the appropriate word(s).
A patient has a staphylococcal infection of the blood; a septicemia - very serious and possibly deadly. As the doctor, you would like to prescribe a relatively non-toxic and inexpensive drug out of the cephalosporin family. However, if the patient harbors a strain of Staphylococcus that is resistant to a variety of antibiotics, you would prefer to use vancomycin-- which is highly effective against Staphylococcus. Which of the following explains why the cephalosporin drug is preferred for use over the vancomycin?
A. Vancomycin is very toxic, and the Staphylococcus strain could become resistant leaving no back-up drugs with which to treat the infection. B. You really do not know that much about vancomycin, so you would rather go with a drug that you can find out more about. C. You would rather give an inexpensive drug to save the family money. D. Vancomycin is one of the most selectively toxic drugs there is, so you would prefer one that has a more broad-spectrum effect.
A plasmid cloning vector and DNA fragments containing the XYZ gene, each digested with the same restriction
enzyme, are mixed with DNA ligase. Which product(s) will result?
a. recombinant plasmids only b. nonrecombinant plasmids only c. joined-together copies of the DNA fragment containing the XYZ gene only d. a mixture of recombinant plasmids, nonrecombinant plasmids, and joined-together copies of the DNA fragment containing the XYZ gene e. no reaction will occur because DNA polymerase rather than DNA ligase is needed to insert the DNA fragments into the plasmid cloning vector
What is the major difference between ionic and covalent bonds?
a. Ionic bonds are reversible; covalent bonds are not. b. Ionic bonds only occur between non-metallic elements. c. In ionic bonds one or more electrons are transferred between atoms, whereas atoms in covalent bonds share electrons. d. Covalent bonds only occur in the presence of radioisotopes.