How can the use of chemical control agents (antibiotics, herbicides, pesticides) lead to their decreased effectiveness?
What will be an ideal response?
By changing the environment, these chemicals selectively kill only the bacteria, weeds, and pests that are not immune to them, leaving mostly those with a natural immunity. The resistant individuals survive and reproduce, giving rise to a new generation that may also be resistant to the drug. Eventually, the chemical is no longer effective against any of them.
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A man visits a doctor, and discovers that, due to tumors, he needs to get both of his carotid bodies removed. What processes will their removal affect in his body? Select all correct
A. His body will not be able to sense the oxygen concentration of brain-bound blood. B. His body will not be able to sense the CO2 concentration of brain-bound blood. C. His body will not be able to sense the oxygen concentration of body-bound blood. D. His body will not be able to sense the CO2 concentration of body-bound blood.
Which of the following statements is true?
a. The fossil record supports Cuvier’s theory of catastrophism. b. According to the theory of catastrophism, more species were alive at the beginning of the world than are now present. c. According to the theory of catastrophism, new species developed out of the survivors of the catastrophes. d. The theory of catastrophism was based upon observable responses that organisms made to catastrophes. e. According to catastrophism there were several distinct periods of creation following each catastrophe.
You notice that over the past month, many students on campus have started wearing a new style of school sweatshirt. You think to yourself that perhaps the bookstore has recently started selling this new sweatshirt style. This is an example of a(n)
A) experimental question. B) type of observation. C) hypothesis. D) experiment.
Which of the following has the largest surface-to-volume ratio?
a. Escherichia coli b. influenza virus c. Roseobacter denitrificans d. Staphylococcus aureus