18.4–18.6
18.4–Flowers have several roles in plant reproduction.
Sexually reproducing angiosperms produce flowers as the chief structure for sexual reproduction.
760
Q
“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.
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.
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
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.
