quiz2akey - a. latent heat loss from the leaf. b. sensible...

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Quiz 2a – IntroBio152, Lec 2, Spring2010 1. To “freshen” some completely wilted spinach leaves ( Ψ = Ψ s = -1.4 MPa), you soak them in tap water with a Ψ s = -0.3 MPa. Assuming that the spinach equilibrates with the solution, what is the resulting pressure potential ( Ψ p ) of spinach cells? (Don’t worry about solute dilution associated with cell water uptake.) a. 0.3 MPa b. 1.4 MPa c. –1.4 MPa d. 1.1 MPa 2. Which of the following typically causes leaf stomates to close? a. an increase in atmospheric CO 2 concentration b. an increase in light intensity c. a decrease in the vapor pressure difference between leaf and atmosphere d. an increase in soil moisture content 3. Leaf water potential ( Ψ ) is typically highest (least negative) a. at dusk b. in the middle of the day c. in late morning d. just before dawn 4. Guard cells directly regulate
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Unformatted text preview: a. latent heat loss from the leaf. b. sensible heat loss from the leaf. c. infrared heat loss from the leaf. d. absorption of solar radiation by the leaf. 5. In order to utilize the “raffinose trap” in phloem loading, symplastic loaders a. convert sucrose to raffinose in the leaf mesophyll. b. use ATPase to load raffinose into the companion cell. c. convert sucrose into raffinose in the companion cell or sieve-tube member. d. load raffinose into the mesophyll apoplast, and convert it into sucrose before loading into the companion cell. 6. P-protein in sieve-tube members serves as a a. short-term plug of sieve plates immediately following phloem injury. b. permanent plug of sieve plates following phloem injury. c. regulator of apoplastic phloem loading. d. regulator of symplastic phloem loading....
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This note was uploaded on 02/19/2010 for the course CHEMISTRY 343 taught by Professor Clauss during the Spring '10 term at Wisconsin.

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