Assuming the same pressure gradient, flow through a xylem conduit with a diameter of 100 F1F1F1S1F1F1F10m is _____ times faster than a similar conduit with a 25-F1F1F1S1F1F1F10m diameter.

A) 4 B) 16 C) 64 D) 256 A) 4 B) 16 C) 64 D) 256 D

CAM photosynthesis improves the CO2/H2O exchange ratio because:

A) organic acids are decarboxylated at night. B) organic acids are decarboxylated in daylight. C) CO2 capture occurs at night when the gradient for diffusion of H2O out of the leaf is smaller. D) CO2 capture occurs at night when the gradient for diffusion of CO2 into the leaf is larger. A) organic acids are decarboxylated at night. B) organic acids are decarboxylated in daylight. C) CO2 capture occurs at night when the gradient for diffusion of H2O out of the leaf is smaller. D) CO2 capture occurs at night when the gradient for diffusion of CO2 into the leaf is larger.

The timing of _____ is a feature that distinguishes CAM and C4 photosynthesis.

A) stomatal opening B) carbohydrate production C) rubisco activity and the Calvin cycle D) mitochondrial respiration A) stomatal opening B) carbohydrate production C) rubisco activity and the Calvin cycle D) mitochondrial respiration

Which of the following statements is TRUE regarding CO2 capture and the Calvin cycle in CAM plants?

A) CO2 capture occurs at night, and the Calvin cycle takes place in the day. B) CO2 is captured in mesophyll cells, and the Calvin cycle occurs in bundle-sheath cells. C) CO2 capture and the Calvin cycle both occur in the same cell. D) CO2 capture and the Calvin cycle both occur during the day (in sunlight). A) CO2 capture occurs at night, and the Calvin cycle takes place in the day. B) CO2 is captured in mesophyll cells, and the Calvin cycle occurs in bundle-sheath cells. C) CO2 capture and the Calvin cycle both occur in the same cell. D) CO2 capture and the Calvin cycle both occur during the day (in sunlight).

A) are modified cell walls that connect sieve elements. B) do not contain plasmodesmata. C) dissolve at sieve tube maturity. D) have solid, impermeable surfaces. E) contain mitochondria and chloroplasts. A) are modified cell walls that connect sieve elements. B) do not contain plasmodesmata. C) dissolve at sieve tube maturity. D) have solid, impermeable surfaces. E) contain mitochondria and chloroplasts.

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