54 The divergence between the two populations of Rhagoletis must have occurred very rapidly because

  • A) The apple tree was imported into North America with European settlement approximately 200 years ago
  • B) Flies were imported into North America with European settlement approximately 200 years ago
  • C) Long-distance rail transport of fruit increased only after the American Civil War (1861 -1865)
  • D) Heavy use of gunpowder during the American Civil War (1861 -1865) led to increased mutation rates in many natural populations of plants and animals
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55 A dog is following the scent of a jackrabbit. Which of the following accurately describes how the dog’s brain integrates information for smell?

  • A) Chemoreceptors in the brain send impulses for smell in the nasal cavity.
  • B) Chemoreceptor cells in the nasal cavity sends impulses to the appropriate area of the brain.
  • C) Chemoreceptors on epithelial cells of the tongue send hormones to the appropriate area of the brain.
  • D) Receptors originating in the nose send action potentials to the motor regions of the brain.
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57 Thrips are insects that feed on rose pollen. Scientists noted that the thrips population increased in the spring and decreased dramatically during the summer. The researchers hypothesized that food abundance was the limiting factor for the population. Which of the following types of data would be most useful for the scientists to collect at regular intervals on a designated test plot of rose plants?

  • A) Amount of sunlight (hours/day)
  • B) Mean temperature (°C)
  • C) Density of rose pollen produced (g/m²)
  • D) Amount of pollen produced by each flower (g/flower)
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