36. Plant Reproduction

The ABC model of flower formation suggests that __________.

The male structures of angiosperms are called __________, and they produce __________.

In the alternation of generations in plants, __________.

Which of the following associations is correct?

Evaluate these statements about double fertilization. Select True or False for each sentence.T/FTwo zygotes are formed, but only one survives.T/FOne sperm fuses with an egg while the other sperm fuses with polar nuclei.T/FIt results in the formation of a diploid embryo and triploid endosperm.T/FBoth sperm involved in double fertilization form within the same pollen tube.

Double fertilization means thata. flowers must be pollinated twice to yield fruits and seeds.b. every egg must receive two sperm to produce an embryo.c. one sperm is needed to fertilize the egg, and a second sperm is needed to fertilize the polar nuclei.d. every sperm has two nuclei.

In angiosperms, each pollen grain produces two sperm. What do these sperm do? a. Each one fertilizes a separate egg cell. b. One fertilizes an egg, and the other is kept in reserve. c. Both fertilize a single egg cell. d. One fertilizes an egg, and the other fertilizes a cell that develops into stored food.

In angiosperms, are sperm and eggs produced by mitosis or meiosis? Which cells are spores? Which structures are gametophytes?