SOLVED

20. With both bacterial and eukaryotic cells constantly dying and breaking down around us, and with a tremendous load of fragmentary DNA washing around in the fluid world, why aren’t genes being transferred among various living organisms at a massive scale daily? A. DNA that is not protected inside a protein coat or membrane is very vulnerable. B. Living cells maintain a very effective barrier to the introduction of large molecules. C. Since a vector appears necessary to snatch up DNA from one protected source and inject it into a cell, “naked” DNA is apparently vulnerable and unable to cross membranes easily. D. All of the choices are correct. E. None of the choices are correct, since DNA is readily exchanged among all organisms in nature. 21. When bone marrow stem cells are removed from the patient, infected with a virus that carries a normal gene, and returned to the patient, this is an example of A. PCR. B. chemotherapy. C. viral disinfection. D. in vivo gene therapy. E. ex vivo gene therapy. 22. Transgenic plant products include all of the following EXCEPT A. soybeans that are resistant to a common herbicide. B. an antibody produced by soybeans to treat genital herpes. C. suicide genes that cause the plants to self destruct after their product has been produced. D. antibodies produced by corn plants that deliver radioisotopes to tumor cells. 23. All of the following are true regarding transgenic animals EXCEPT A. foreign genes are micro-injected into eggs, fertilized in vitro, and the zygotes are placed in host females to develop. B. the process has created mice that have a phenotype similar to that of a person with cystic fibrosis. C. the process has been used to develop organisms that are partially animals and partially plant. D. the product desired by the transgenic procedure may be secreted in the milk of female offspring. 24. Gene pharming is the use of A. transgenic plants to produce larger vegetables and sweeter fruits. B. bacteria to produce organic compounds like aspartame and phenylalanine. C. STR profiling to determine evolutionary relationships among organisms. D. transgenic farm animals to produce pharmaceuticals. 25. It is estimated that humans have approximately ______ base pairs in our genome. A. 3 billion B. 2.5 million C. 180 million D. 12 trillion  Â