Lecture 9 Flashcards
Plant hormonal regulation differs from animal hormonal regulation in that _____.
a. there are no dedicated hormone-producing organs in plants as there are in animals
b. all production of hormones is local in plants with little long-distance transport
c. only animal hormones may have either external or internal receptors
d. only animal hormone concentrations are developmentally regulated
a. there are no dedicated hormone-producing organs in plants as there are in animals
Plant hormones produce their effects by _____.
I) altering the expression of genes
II) modifying the permeability of the plasma membrane
III) modifying the structure of the nuclear envelope membrane
a. only I
b. only II
c. only III
d. only I and II
d. only I and II
Which of the following statements best summarizes the acid-growth hypothesis in an actively growing shoot?
a. Auxin stimulates proton pumps in the plasma membrane and tonoplast.
b. Auxins and gibberellins together act as a lubricant to help stretch cellulose microfibrils.
c. Auxins activate aquaporins that increase turgor pressure in the cells.
d. Auxin-activated proton pumps lower the pH of the cell wall, which breaks bonds and makes the walls more flexible.
d. Auxin-activated proton pumps lower the pH of the cell wall, which breaks bonds and makes the walls more flexible.