Endosperm is formed when:

a. two sperm from the pollen grain fuse with each other.

b. two nuclei from the embryo sac fuse with each other.

c. a sperm nucleus from the pollen fuses with the egg nucleus in the embryo sac.

d. a pollen grain lands on a stigma.

e. a sperm nucleus from the pollen grain fuses with two central cell nuclei in the embryo sac.

The difference between a seed coat and fruit is that (select all that apply):

a. fruit is always edible; seed coats are not.

b. seed coats are always hard; fruits are always soft.

c. seed coats develop from ovules while fruit tissue develop from ovaries.

d. dicots produce seed coats while monocots produce fruit.

e. fruit is tissue that develops outside the seed coat.

The pollen of gymnosperms generally is transported by _______, while the pollen of angiosperms generally is transported by _______.

Plants respond to gravity, touch, and the direction of sunlight through the _______ growth of roots or stems.

Plants in temperate climates make seasonal adjustments based on the relative length of the _______ they are experiencing.

A seed is a plant structure that includes a plant ______, its _____ supply, and a tough ______.

Of the following plants, which produce(s) seeds? (a) moss, (b) fern, (c) spruce tree, (d) orchid.

In their role as the male gametophyte generation of seed plants, pollen grains contain plant ____.

Which of the following traits is «of characteristic of plants? (a) fixed-in-place, (b) no cell wall, (c) photosynthesizing, (d) mostly land-dwelling.

All plants go through an alternation of generations in which one generation produces the reproductive cells called _______, while the alternate generation produces the reproductive cells that fuse in reproduction, _______ and _______.

As readers of the evolution section of this book know, a lack of genetic diversity can be harmful to a population of living things (see Chapter 17, page 308, for more). Can you think of an aspect of plant functioning that (a) has grown more sophisticated over evolutionary time and that (b) helps ensure genetic diversity among plants?