Final example

Rubisco is more likely to perform the oxygenase reaction during the night than during the day. T/F
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Terms in this set (22)
Rubisco is more likely to perform the oxygenase reaction during the night than during the day. T/F
False
Rubisco is inactive at night
The Calvin Benson Cycle is active during the day in C3, C4 and CAM plants. T/F
True
The Calvin Benson cycle is active during the day in all plants that use it
You discover a mutant that is defective in gravitropism but has normal phototropism. What is most likely to be defective in the mutant?
The mutant lacks starch.
Since phototropism is normal, things related to polar auxin transport and response must be functioning normally. Gravity is perceived by amyloplasts containing starch and this is something specific to gravitropism. Therefore, a defect in starch accumulation is the best answer.
Starting with the outer whorl and moving inward, the organs of a flower of a plant lacking both the B and C class floral organ identity proteins will be...
Sepal, Sepal, Sepal, Sepal
Mutating C function allows A function to be expressed on all whorls. Since B and C are absent, all whorls only express A function. A function alone in a whorl specifies sepal organ identity. Therefore all whorls will be sepals.
Bulk flow of water in the xylem cannot occur when stomates are closed and the plant transpiration rate is zero. T/F
False
Water can move in the xylem even when there is no transpiration because water can move between the phloem and xylem. Water exiting the phloem at the sink can enter the xylem and move to another location, likely the source since the source is where the phloem is loaded and water enters the phloem.
Which of the following will likely lead to a reduction in transpiration?
A decrease in the water potential around the guard cells.
Closing stoma will decrease transpiration. The one condition that does this is reducing the water potential around guard cells, which causes water to exit the guard cells and closing of the stoma. The change in ABA and solute potential in surrounding cells will not do this. Decreasing the water potential of the air will tend to increase transpiration.
Mark all of the statements about glyceraldehyde 3-phosphate that are true.
- Glyceraldehyde 3-phosphate is produced by the reduction phase of the Calvin-Benson cycle.
- Glyceraldehyde 3-phosphate is more reduced than the 3-carbon compounds produced by Ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco).
- Some glyceraldehyde 3-phosphate is removed from the Calvin-Benson cycle and converted to starch or sucrose.
Increasing the chloroplast lumen pH will activate processes that reduce the production of singlet oxygen. T/F
False
Reducing not increasing the lumen pH activates processes that protect the plant by preventing excess absorbed light energy being used to produce singlet oxygen
On a volume basis, phloem contents have more energy than the xylem contents. T/F
True
The phloem has more solute and the solute is rich in reduced carbon compounds.
Ethylene
The only gaseous plant hormone. Among its many effects are response to mechanical stress, programmed cell death, leaf abscission, and fruit ripening.
Image: Ethylene
Auxin (IAA)Promotes plant growth by increasing H+ concentration activating enzymes that loosen cellulose fibers thereby expanding the cell wall also plays a role in phototropism and gravotropismGibberellin (GA)plant hormone that stimulates shoot elongation, seed germination, and the maturation and dropping of fruit and flowersAbscisic acid (ABA)A plant hormone that slows down growth, promotes seed dormancy and facilitates drought tolerance.Some green revolution semidwarf varieties have a mutant form of the DELLA protein that is stabilized by the mutation. Stabilizing the DELLA protein can slow or even inhibit germination? Reducing the concentration of what hormone could improve the germination of these DELLA mutants?Abscisic acid (ABA) DELLA proteins are involved in GA signaling. The mutant has reduced GA signaling and thus reduced germination. Since ABA and GA act oppositely during germination reducing ABA levels would promote germination.During germination of barley seeds, gibberellin is released from the __________. When this GA reached the ______________, it triggers the synthesis and release of alpha-amylase from this tissue. Alpha-amylase hydrolyzes ____________ that is stored in the endosperm tissue.1. embryo 2. aleurone layer 3. starchMutating which of these photoreceptors will prevent the induction of photomorphogenesis in by far-red light?Phytochrome A (phyA) phyA mutants do not undergo photomorphogenesis under far-red light. Therefore phyA is the photoreceptor for far-red light.Root have spatially distinct zones. These zones are the meristematic zone, cell expansion zone and maturation zone. Which of the following would be a good marker that you could look for to identify the maturation zone? (Which feature is unique to the maturation zone?)Secondary cell wall Since cells in the meristematic zone and elongation zone can grow but this is not necessarily true of the maturation zone. Secondary cell wall would only occur in the maturation zone. The other possibilities are found in almost all cells.Insect feeding on tomato leaves causes a protein to be cleaved, releasing ____________, a peptide hormone. This peptide hormone induces the synthesis of jasmonic acid. Jasmonic acid moves to other parts of the plant in the phloem and cells receiving this hormone begin producing ____________ inhbitors. These inhibitors interfere the insect's ability to digest plant material, making the plant less nutritious. Through the mechanism tomato defends itself against herbivory.1. systemin 2. proteaseWhich of these hormones promotes the ripening of climateric fruit?ethylenePulses of light can entrain a rhythm that is free running constant darkness. T/FTrueStratification is a cold treatment that induces flowering. T/FFalse Vernalization not stratification is a cold treatment that induces flowering. Stratification is a cold treatment that induces seed germination.The presence of which of the following would indicate a cell cannot increase in size?Lignin Lignin is found in cells with secondary cell walls. Lignin makes the wall rigid and unable to expand.