18.4–18.6: Flowers have several roles in plant reproduction.

Sexually reproducing angiosperms produce flowers as the chief structure for sexual reproduction.

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Question 18.24

“Double fertilization” in angiosperm plants refers to the:

  • a) release of two sperm from a single pollen grain.
  • b) production of two or more eggs in the ovary.
  • c) fusion of the ovary with the anther.
  • d) fusion of a sperm cell with two nuclei of the endosperm-forming cell.
  • e) fusion of one sperm cell with the egg and another with two nuclei of the endosperm-forming cell.

Question 18.25

Which of the following is a likely way in which plants increase dispersal of their fruit?

  • a) Fruits are conspicuously colored.
  • b) Fruits taste good.
  • c) Fruit stems are highly elastic.
  • d) Both a) and b) are true.
  • e) Both a) and c) are true.

Question 18.26

Which of the following is the proper sequence of events when a flowering plant reproduces?

  • a) meiosis; pollination; fertilization; embryo formation
  • b) fertilization; meiosis; nuclear fusion; endosperm formation
  • c) growth of the pollen tube; pollination; germination; fertilization
  • d) meiosis; fertilization; growth of the pollen tube; germination
  • e) mitosis; embryo formation; pollination; seed development

Question 18.27

For angiosperms, which of the following statements about growth is the most correct?

  • a) Vascular cambium increases girth; cork cambium increases length.
  • b) Apical meristems increase length; vascular cambium increases girth.
  • c) Cork cambium increases length; apical meristems increase girth.
  • d) Apical meristems increase length; apical meristems increase girth.
  • e) Apical meristems increase girth; vascular cambium increases length.