17.4–17.7: Most plants have common structural features.

The body plans of plants are organized around three structures: roots, stems, and leaves.

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Question 17.26

For a typical green plant to thrive, it needs:

  • a) sunlight, water, carbondi oxide, oxygen, and minerals.
  • b) only water.
  • c) only minerals.
  • d) only sunlight.
  • e) only sunlight, water, oxygen, and minerals.

Question 17.27

Plants do not grow well in pure clay soils because:

  • a) the soil packs so tightly that the roots cannot penetrate it.
  • b) the soil packs so tightly that the amount of oxygen reaching the roots is limited
  • c) water drains too rapidly.
  • d) the mineral content is very low.
  • e) clay holds water and will not release it to the roots.

Question 17.28

The enzyme known as __________ catalyzes the fixation of nitrogen in nitrogen-fixing bacteria.

  • a) nitrogen reductase
  • b) nitrogenase
  • c) rhizobiase
  • d) ammoniase
  • e) nitrogen fixase

Question 17.29

All of the following statements about carnivorous plants are correct except:

  • a) The carnivorous structures (such as pitchers) contain chloroplasts and are photosynthetic.
  • b) The carnivorous structures are less efficient at photosynthesis than typical leaves.
  • c) Increasing the amount of nitrogen available to a pitcher plant causes a decrease in the plant’s investment in carnivorous structures.
  • d) Carnivorous plants usually cannot outcompete non-carnivorous plants in nutrient-rich soils.
  • e) Carnivorous plants thrive in nitrogen-rich tropical habitats.