Which of the following is a mechanism by which new susceptible individuals enter a population?
A. Birth of new individuals
B. Migration of individuals into the population
C. Birth of new individuals and migration of individuals into the population
D. Enhancement of immune systems through immunization
Answer: C
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A researcher is interested in studying gene X, but not gene Y, in Drosophila. What does she need to amplify only gene
X from the Drosophila genome?
a. some prior knowledge of the gene X sequence so appropriate primers can be designed b. a heat-stable restriction endonuclease c. restriction endonucleases that cut gene X but not gene Y d. a cloning vector that has multiple antibiotic resistance genes e. a cloning vector that will ligate to gene X but not to gene Y
Most of the tallgrass prairies have been converted ____
a. to grazing lands b. for citrus production c. to homesteads d. to croplands e. to vineyards
Your 81-year old grandfather has been diagnosed with cancer of the thymus. The doctor is urging surgical removal of the cancer, but you and the family are worried about the consequences of removing an entire organ such as the thymus. Which statement is correct?
A. Your grandfather will have a loss of T lymphocytes and will have an immune deficiency. B. There is nothing to worry about; thymus removal will not affect your grandfather's immune status at his age. C. Your grandfather would not be able to produce complement proteins necessary for pathogen control and inflammation. D. Your grandfather would not have sufficient phagocytic cells and would not be able to contain bacterial infections.
Ned is reading his newspaper by holding it at arm's length. Sandra asks him why he isn't holding it closer. He explains that he would not be able to see the print if he held it closer
Which of the following corrective measures would be the best solution for Ned? A) corneal ring segments B) retinal transplants C) convex lenses D) concave lenses