Plant Structure/Growth and Nutrient Acquisition

Which part of a plant absorbs most of the water and minerals taken up from the soil?

• root cap

• root hairs

• the thick parts of the roots near the base of the stem

• storage roots

Which of the following have unevenly thickened primary walls that support young, growing parts of a plant?

• parenchyma cells

• collenchyma cells

• sclerenchyma cells

• tracheids

One important difference between the anatomy of roots and the anatomy of leaves is that

• only leaves have phloem and only roots have xylem.

• root cells have cell walls and leaf cells do not.

• a waxy cuticle covers leaves but is absent from roots.

• vascular tissue is found in roots but is absent from leaves.

Plants contain meristems whose major function is to

• produce more cells.

• attract pollinators.

• absorb ions.

• photosynthesize.

Carbon dioxide enters the inner spaces of the leaf through the

• cuticle.

• epidermal trichomes.

• stomata.

• walls of the guard cells.

Given that early lad plants most likely share a common ancestor with green algae, the earliest land plants were most likely

• nonvascular plants that grew leafless shoots above the shallow fresh water in which they lived.

• species that did not exhibit alternation of generations.

• vascular plants with well-defined root systems.

• plants will well-developed leaves.

Which of the following would be LEAST likely to affect osmosis in plants?

• proton pumps in the membrane

• a difference in solute concentrations

• receptor proteins in the membrane

• aquaporins

The value for Ψ in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (Ψ = -0.23 MPa), the net water flow would

• be from the tissue into the sucrose solution.

• be from the sucrose solution into the tissue.

• be in both directions and the concentrations would remain equal.

• occur only as ATP was hydrolyzed in the tissue.

Compared to a cell with few aquaporins in its membrane, a cell containing many aquaporins will

• have a lower water potential.

• have a higher water potential.

• have a faster rate of active transport.

• have a faster rate of osmosis.

Photosynthesis begins to decline when leaves wilt because

• chloroplasts within wilted leaves are incapable of photosynthesis.

• CO₂ accumulates in the leaves and inhibits the enzymes needed for photosynthesis.

• there is insufficient water for photolysis during the light reactions.

• stomata close, restricting CO₂ entry into the leaf.