Week 11 Homework

Which of the following statements is TRUE regarding CO2 capture and the Calvin cycle in CAM plants? (Select all that apply.) Correct! A. CO2 capture occurs at night, and the Calvin cycle takes place in the day. B. CO2 capture and the Calvin cycle both occur during the day (in sunlight). C. CO2 capture and the Calvin cycle both occur in the same cell. D. CO2 is captured in mesophyll cells, and the Calvin cycle occurs in bundle-sheath cells.

A. CO2 capture occurs at night, and the Calvin cycle takes place in the day. C. CO2 capture and the Calvin cycle both occur in the same cell.

If the two guard cells of a stoma increase their concentration of potassium (K+) ions, what will happen to the corresponding pore? A. The pore will open, allowing CO2 to diffuse into the leaf. B. The pore will close, preventing water vapor from diffusing out of the leaf. C. The pore will open, allowing water vapor to diffuse into the leaf. D. The pore will close, preventing CO2 from diffusing out of the leaf.

A. The pore will open, allowing CO2 to diffuse into the leaf.

Why may young leaves that are just emerging from the bud be considered "sinks" for phloem transport? A. They consume more carbohydrates than they produce. B. They produce carbohydrates through photosynthesis. C. They do not have developed sieve tubes. D. The sucrose concentration is too high.

A. They consume more carbohydrates than they produce.

Land plants are descended from: A. green algae. B. cyanobacteria. C. brown algae. D. mosses.

A. green algae.

When stomata are open and a plant is transpiring normally, water moves from the soil into the root xylem: (Select all that apply.) A. in a flow that is ultimately driven by evaporation from the shoot. B. without the plant doing any additional work on the fluid. C. due to a force generated by the partial dehydration of cell walls in leaves. D. due to the action of ATP driven pumps in the endodermis.

A. in a flow that is ultimately driven by evaporation from the shoot. B. without the plant doing any additional work on the fluid. C. due to a force generated by the partial dehydration of cell walls in leaves.

Which of the following would be considered a carbohydrate sink in vascular plants? (Select all that apply.) A. roots B. stems C. flowers D. mature leaves

A. roots B. stems C. flowers

_____ are the structures formed by roots that house nitrogen-fixing bacteria. A. Root caps B. Root nodules C. Mycorrhizae D. Root hairs

B. Root nodules

In many soils, there is more than enough phosphorus to support plant growth, but that element is tightly bound to soil particles and thus largely unavailable. Which of the following are potential solutions to this problem for vascular plants? (Select all that apply.) A. They can raise soil pH. B. They can pump H+ into the soil. C. They can form symbiotic relationships with bacteria. D. They can form symbiotic relationships with mycorrhizae.

B. They can pump H+ into the soil. D. They can form symbiotic relationships with mycorrhizae.

Which of the following are classified as land plants, but not as vascular plants? A. gymnosperms B. liverworts C. algae D. angiosperms E. lycophytes

B. liverworts

Which of the following are NOT a correct match of cells and their function? A. companion cells: protein synthesis and cell metabolism B. parenchyma cells: transport of water C. vessel elements: transport of water D. sieve elements: transport of sugars E. tracheids: transport of water

B. parenchyma cells: transport of water

The structure(s) that allow(s) gasses, such as CO2, to diffuse into and out of a leaf is/are the: A. veins. B. stomata. C. vascular bundles. D. mesophyll cells. E. cutlcle.

B. stomata.

Nitrogen fixation: A. is performed by biochemical pathways in the plant cells. B. releases N2 gas to the atmosphere. C. converts N2 to ammonia, making it available for incorporation into amino acids and nucleotides. D. incorporates molecular nitrogen (N2) taken from the air into amino acids and nucleotides. E. is necessary for the electron-transport chain because nitrogen acts as the final electron acceptor.

C. converts N2 to ammonia, making it available for incorporation into amino acids and nucleotides.

One of the earliest evolutionary adaptations that helps plants to retain water in a terrestrial environment is the: A. leaf. B. phloem. C. cutlcle. D. root. E. xylem.

C. cutlcle.

In which direction would phloem sap flow if there were a greater concentration of sucrose molecules in the root phloem compared with the leaf phloem? A. in the opposite direction to xylem flow B. from leaf to root C. from root to leaf D. There would not be enough turgor pressure to move the sap.

C. from root to leaf

A researcher discovers a mutant pea plant that is missing the Casparian strip. What process will be affected in this mutant? A. the diffusion of CO2 into the leaves of the plant B. the ability of the plant to perform CAM C. the entrance of nutrients into the roots of the plant D. both the diffusion of CO2 into the leaves of the plant and the opening and closing of stomata E. the opening and closing of stomata

C. the entrance of nutrients into the roots of the plant

If water molecules (H2O) suddenly stopped forming hydrogen bonds with each other, how would water transport in vascular plants change (if at all)? A. It would remain the same, because water transport only depends on osmosis. B. It would increase, because hydrogen bonds inhibit water transport. C. It would remain the same, because H2O molecules also form oxygen bonds. D. It would stop, because water transport relies on H2O molecules being connected by hydrogen bonds.

D. It would stop, because water transport relies on H2O molecules being connected by hydrogen bonds.

Assuming the stomata are open to the same degree, the rate of transpiration should _____ on a rainy day compared with a sunny day because the H2O concentration gradient from the inside to the outside of the leaf would _____. A. increase; decrease B. increase; increase C. decline; increase D. decline; decrease E. remain the same; not change

D. decline; decrease

Photorespiration: A. is a process similar to cellular respiration, producing energy for plants. B. generates ATP. C. occurs in equal parts with photosynthesis. D. is due to rubisco being able to bind O2 as well as CO2. drives photosynthesis.

D. is due to rubisco being able to bind O2 as well as CO2. drives photosynthesis.

Which of the following are produced by roots in order to increase surface area, allowing greater access to nutrients in the soil? A. root nodules B. root Casparian strips C. root parenchyma D. root hairs

D. root hairs

Which of the following statements is FALSE regarding the relationship of xylem and phloem? A. The number and volume of xylem conduits greatly exceeds the number and volume of sieve tubes. B. In phloem, the plant's metabolic activity generates the force that drives transport, whereas movement in xylem is largely driven by transpiration. C. The volume of water moving through the phloem is small compared with that moving through the xylem. D. Water exiting the phloem may enter the xylem and be transported to leaves. E. Phloem cells are dead at maturity, whereas xylem cells are alive at maturity.

E. Phloem cells are dead at maturity, whereas xylem cells are alive at maturity.