Questions and Answers

Water flows upward in some xylem tubes and downward in others.
a) True
b) False

Bacteria-containing nodules in the roots of legume plants aid in the utilization of:
a) trace elements.
b) carbon dioxide.
c) nitrogen.
d) water.
e) phosphates.

What cellular feature allows a mineral such as manganese to diffuse from cell to cell after being taken up by roots?
a) microfilaments
b) secondary cell walls
c) sieve plates
d) plasmodesmata
e) microtubules

All of the following are part of a plant’s shoot system EXCEPT:
a) mycorrhizae.
b) flowers.
c) stem.
d) buds.
e) leaves.

Diffusion doesn’t require energy. Why do plants expend energy in active transport to transport minerals into root hairs?
a) Minerals are strongly attracted to soil particles.
b) Mineral concentrations in the soil are too high for diffusion.
c) Minerals are too large for diffusion.
d) Mineral concentrations in the soil are too low for diffusion.

The concentration of nutrients in plants is approximately the same as the concentration of nutrients in the surrounding soil.
a) True
b) False

Based on this scenario, which plant is most likely a legume with nitrogen-fixing bacteria?
You found the following plants growing on campus during a field trip:
a) a small plant with a notable absence of root hairs;
b) a short, stubby plant with an enlarged taproot;
c) a tall annual herb with fungal strands extending from its roots;
d) a low-growing plant with nodules on the roots;
e) a woody shrub with an extensive fibrous root system.

The ________ theory explains the movement of water and minerals through xylem.
a) bulk-flow theory
b) assisted diffusion theory
c) cohesion-tension theory
d) translocation theory
e) pressure-flow theory

In the cohesion-tension theory, “cohesion” refers to the:
a) use of water in photosynthesis, resulting in a shortage of water in the leaf.
b) tendency of water molecules to be attracted to minerals in the water.
c) attraction of water molecules for one another.
d) evaporation of water from the stomata of the leaf.
e) process of osmosis that pulls water into the root.

When potassium ion is transported into guard cells, water:
a) enters by osmosis.
b) is actively transported out of the cells.
c) moves to the edge of the cell.
d) leaves by osmosis.
e) is actively transported into the cells.