The “race for sunlight” in plants led to the evolution of the tallest living things in existence, trees. But sunlight is not the only thing that stands to make a tree successful or not in reproducing. Think about how plants function and then answer this question: What are the costs of being taller, as opposed to shorter?

Plants take in _____ and _____ through their roots, but take in ____ primarily through tiny pores on their leaves.

a. minerals; carbon dioxide; water

b. oxygen; carbon dioxide; water

c. water; carbon dioxide; minerals

d. oxygen; minerals; carbon dioxide

e. minerals; water; carbon dioxide

It’s sometimes said that plants are much more efficient organisms than animals, in that they consume fewer resources and produce fewer waste products. Evaluate this statement in light of what you have learned about the functioning of angiosperms.

Which of the following are not functions of roots? (Select all that apply.)

a. nutrient storage

b. loss of water through transpiration

c. loss of oxygen in photosynthesis

d. grow to water supplies

e. absorption of water

Gardeners often speak of outdoor plants having become “established,” meaning the plants have reached a point at which they need less human care. What threshold does a plant have to cross to become established?

Dermal tissue _________, while vascular tissue ________.

a. protects the plant; conducts fluids

b. provides strength; facilitates growth

c. facilitates reproduction; protects the plant

d. facilitates growth; provides strength

e. protects the plant; facilitates reproduction

Which of the following statements about the ascent of water in tall trees is true? (Select all that apply.)

a. Plants must expend their own metabolic energy to power the ascent of water into treetops.

b. The evaporation of water from leaf surfaces pulls water from the roots to the canopy of a tall tree.

c. The ascent of water in the xylem is fastest when the stomata are closed.

d. The ultimate source of energy for the ascent of water is the sun.

e. All of the above are true.

Pressure develops inside phloem sieve tubes because:

a. osmotic uptake of water occurs when sugars are loaded into the sieve elements.

b. sieve elements lack a nucleus.

c. sieve elements are dead at maturity.

d. sucrose is a bulky molecule that exerts a pressure against the sieve tube walls.

e. All of the above are true.

Which of the following statements about plant spores is true? (Select all that apply.)

a. They are another name for gametes.

b. The multicellular gametophyte generation develops from them.

c. They produce the eggs and sperm that fuse to produce a new sporophyte generation.

d. They are part of the sporophyte generation.

e. They are much smaller than gametes.

Which of these is a gametophyte plant? (Select all that apply.)

a. petal

b. stigma

c. embryo sac

d. sepal

e. pollen grain

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.