Exam 2 Flashcards
The water lost during transpiration is a side effect of the plant’s exchange of gases. However, the plant derives some benefit from this water loss in the form of:
evaporative cooling and mineral transport
Plants often use changes in day length (photoperiod) to trigger events such as dormancy and flowering. It is logical that plants have evolved this mechanism because photoperiod changes:
are more predictable than air temperature changes
The following is true about nitrogen fixation in root nodules:
Leghemoglobin helps maintain a low oxygen concentration within the nodule
Leaf thickness represents a trade-off between:
water retention and CO2 absorbtion
Where are the youngest wood and youngest bark in a tree trunk?
Youngest wood is toward the outside, near the vascular cambium. youngest bark is the inner part, next to the vascular cambium
Cell-to-cell water movement always occurs from:
higher to lower water potential
The following is a source for products of photosynthesis in a tree that loses its leaves in winter
Roots in early Spring
The best ways to detect a lack of photosystem II in these organisms would be:
test for liberation of O2 in the light
Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will most directly affect the
synthesis of ATP
the following statement best represents the relationships between the light reactions and the Calvin cycle?
The light reactions provide ATP and NADPH to the Calvin cycle, and the Calvin cycle returns ADP, organic phosphate, and NADP+ to the light reactions.
CAM plants keep stomata closed in the daytime, thus reducing loss of water. They can do this because they
fix CO2 into organic acids during the night
The following sequence correctly represents the flow of electrons during photosynthesis:
H2O to NADPH to Calvin cycle
What will happen to a red blood cell (RBC), which has an internal ion concentration of about 0.9 percent, if it is placed into a beaker of pure water?
the cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC
How can you prune a tree to trigger it to increase the number of branches?
cut off the tips of the main shoots
the contestants must get their plant to grow in a pattern that matches the path through the maze. You need the money and feel confident that you can accomplish this task. Which of the following techniques will help you succeed?
Inject compounds that block auxin receptors into the part of the stem opposite from the direction you want the stem to bend.
