Bio 212 Week 4 Test Questions with Correct Answers

The opening of depolarization gated potassium channels is a step in the closure of stomata through reducing pressure in guard cells You can count on a co transporter and not a channel being used when a cell is moving something _____ ______. against driving force Increasing the difference in concentration of K+ between animal cell cytoplasm and the surrounding interstitial fluid would... decrease the membrane potential of a cell (hyperpolarize it) What most directly opens potassium channels during stomatal responser to ABA? membrane depolarization During stomatal opening the ion moving through a channel is being driven by a membrane potential that is stronger than an opposing equilibrium potential. Which of the following provides evidence that the promotion of stomatal opening by High Temperature 1 (HT1) does not occur downstream of the activity of the proton pump? The fact that fusicoccin opens stomata in both wild type and HT mutant plants The response to ABA is about the same in wild type and HT1-2 mutant plants True The stomatal pore diameter (aperature) of an HT1-2 mutantplant in any CO2 environment is the same as The stomatal pore diameter of a wild type plant in low levels of CO2 Which of the following best fits the data from the Serna paper? HT1 regulates proton pump activity. It increases the level of pump activity when CO2 levels are ambient (neither high nor low), increases pump activity even more when CO2 levels are below ambient levels, but does not alter pump activity at high CO2 levels An HT1::GUS construct added to a wild type plant would... have blue stomata An animal cell treated with something that blocked sodium flow would have a resting potential... very close to the equilibrium potential of potassium