Chapter 33

Which best describes a micronutrient? a.It makes up \(96 \%\) of the plant's dry mass. b. It cannot be replaced artificially. c. It is early on the periodic chart compared with macronutrients. d. It is required in large amounts during sunlight hours. e. It is an essential element.

Nutrient runoff from fertilizing lush lawns often causes "al. gal blooms" in nearby lakes, making swimming impossible. The fertilizer components most likely to have caused the blooms are: a. iron, magnesium, and nitrogen. b. \(\quad\) nitrogen, phosphorus, and sulfur. c. nitrogen, potassium, and phosphorus. d. selenium, magnesium, and potassium. e. nitrogen, magnesium, and nickel.

Which of the following is/are not among the ideal soil conditions for growing crops? a. extremely large air spaces b. sandy or silty loam c. blend of sand and clay d. thick top soil e. less than \(5 \%\) humus

Which of the following processes contributes to the uptake of mineral ions by plant roots? a. chlorosis b. osmosis c. anion exchange d. cation exchange e. growth of root hairs

Which of the following does not influence soil pH? a. rainfall b. hydroponic growth c. release of sulfur and nitrogen oxides into the air d. decomposition of organisms e. weathering of rock

Which of the following is a process that helps plants utilize nitrogen? a. nitrogen-fixing bacteria synthesizing nitrate b. \(\quad\) ammonifying bacteria using ammonium to produce nitrate c. nitrifying bacteria converting \(\mathrm{NH}_{4}^{+}\) to \(\mathrm{NO}_{3}^{-}\) d. the absorption of \(\mathrm{NH}_{4}+\) by root hairs the absorption of atmospheric \(\mathrm{N}_{2}\) into the xylem

The nod genes in the bacteria in soybean nodules allow the bacteria to fix nitrogen. Which of the following is not a step in this process? a. The products of nod genes cause cells of the root cortex to divide and become the root nodule in which bacteroids fix nitrogen for the plant. b. In the cortex cells bacteria enlarge and become immobile, forming bacteroids. c. Bacteria enter the root hair cell and multiply, causing the cell plasma membrane to form an infection thread that extends into the root cortex. d. Roots release flavonoid, which turns on the expression of bacterial nod genes. Products of nod genes cause the tip of the root hair to curl toward the bacteria. e. Root hairs trigger release of bacterial enzymes that break down root hair cell walls. f. All of the above are steps in the process.

Carnivorous plants are deficient in: a. oxygen. b.phosphorus. c. potassium. d. nitrogen. e. carbon.

Haustorial roots are characteristic of plants that are: a. \(\quad\) parasites. b. epiphytes. c. nitrate fixers. d. leghemoglobin users. e. carnivorous.

Identify the correct match of a nutrient with its function. a. \(\quad\) chlorine: component of several enzymes b. potassium: component of nucleic acids c. phosphorus: component of most proteins d. manganese: role in shoot and root growth e. calcium: maintenance of cell walls and membrane permeability