Exam 39: Plant Sensory Systems, signals, and Responses

In lettuce seeds,blue light initiates germination.If you measured hormone levels within the seed,which hormone would be produced upon exposure to blue light?

Based on the findings presented above,combined with what you have learned about the hypersensitive response,which sequence of events occurs when a pathogen infects a plant cell? (Only some of the events will be used) 1) The R protein binds to the avr protein. 2) The pathogen releases avr proteins. 3) The plant cell produces nitric oxide. 4) The pathogen produces reactive oxygen intermediates. 5) A signal transduction cascade occurs. 6) The plant cell and the pathogen die. 7) The pathogen dies,the plant cell lives. 8) The plant cell produces both nitric oxide and reactive oxygen intermediates.

If a Venus flytrap were treated with a drug that inhibited the H⁺-ATPase,which of the following would likely happen?

Suppose a plant had a photosynthetic pigment that absorbed far-red wavelengths of light.In which of the following environments could that plant thrive?

Why does Arabidopsis have 5 genes that code for phytochrome?

You grew reed canary grass seedlings in the dark and cut off their tips.You then placed the tips on agar blocks,one in dark and one in light.Based on your knowledge of auxin movement and stability in light,predict the concentration of auxin in the agar blocks.

You are out working in your garden,and you notice that one of your favorite flowering plants has black,dead spots on the leaves.You immediately suspect that the plant has been invaded by a pathogen and has initiated a

What do abscisic acid and gibberellins have in common?

What can you conclude based only on the information in the preceding paragraph?

If a particular species of bacterium were able to produce a substance that breaks down reactive oxygen intermediates and inhibits the production of nitric oxide,it would be less effective at infecting plant cells.

Which of the following is the correct sequence of events after a receptor perceives a signal?

If cells in the ________ are removed,roots will no longer respond to gravity.

Which of the following is the strongest evidence that cytokinins regulate cell divisions?

When tobacco plants were exposed to far-red light,they exhibited increased stem length,petiole length,and petiole angle.These three responses are part of the shade avoidance response.When the same plants were exposed to small concentrations of ethylene while being exposed to far-red light,they exhibited even greater increases in stem length,petiole length,and petiole angle.In a subsequent experiment,tobacco plants showed an increase in ethylene production in response to far-red light.Moreover,mutant plants that are insensitive to ethylene did not show a shade avoidance response when exposed to far-red light.Taken together,these data suggest that ethylene

You buy some fresh fruit at the grocery store.When you get home,you are in a hurry,and you put the fresh fruit in the crisper with some overripe fruit.At the end of the week you are disappointed to find that your new fruit has already become overripe.What happened?

Which of the following changes would be triggered by a signal transduction cascade?

Antisense gene sequences can be used to block the transcription of specific genes in a cell or group of cells.Suppose you treated a seed with an antisense sequence that blocked the transcription of GAMyb transcription factor.What would happen to the seed?

Put the following events of the acid growth hypothesis in order. 1. Cell wall softens and expands. 2) Sugar enters the cell via proton cotransporters. 3) Protons are pumped out of the cell by H⁺-ATPases. 4) Positively charged ions enter the cell. 5) New cellulose microfibrils are produced to extend cell length. 6) Water enters the cell via osmosis,and the cell swells.

A certain species of bacterium is not very effective at colonizing potato plants because the potato plants have a resistance gene that responds to the presence of the bacterium.Which of the following mutations would make the bacterium more successful at invading the potato plant?

A population of plants experiences several years of severe drought.Much of the population dies due to lack of water,but a few individuals survive.You set out to discover the physiological basis for their adaptation to such an extreme environmental change.You hypothesize that the survivors have the ability to synthesize higher levels of ________ than their siblings do.