|Plant Physiology (Biology 327) - Dr. Stephen G. Saupe; College of St. Benedict/ St. John's University; Biology Department; Collegeville, MN 56321; (320) 363 - 2782; (320) 363 - 3202, fax; firstname.lastname@example.org|
Quiz: Phloem Transport
Definition Question: Using a single sentence (or two), define or describe the following.
Multiple Choice Questions:
a. was once called slime
b. can occur in various forms including crystalline, granular and fibrous
c. is dispersed throughout the sieve element
d. is initially synthesized in the companion cells
e. just occurs in angiosperms
f. plugs sieve pores when the sieve elements are damaged
g. is comprised of amino acids
h. all of the above are correct except f & g
i. all of the above are correct
j. none of the above are correct
2. When damaged, sieve
elements are plugged by:
d. beta 1,3-glucans
e. guttation droplets
f. a & b are correct
g. a, b, and d are correct
h. a, b, c and d are correct
3. Phloem contents are
a. high water potential to low water potential
b. high pressure to low pressure
c. an area of low sugar concentration to an area of high sugar concentration
d. from a sink to a source
4. Which of the following
is most likely to be a source?
a. young leaves
b. developing fruits
c. taproots in the spring
d. taproots in the summer
5. Which of the following
materials would you least likely expect in the phloem of all plants?
Scratch Question: Put a line through the structures in the following list that are uncommon or not likely to be found in a sieve element.
Sequence Question: Draw a double osmometer. Label the left side A and the right side B. If the system is initially filled with water and then sucrose is added to side (A), number the following in the appropriate sequence of occurrence. The first one is done for you.
|1.||sucrose is added inside the membrane on Side A|
|flow stops (no net flow into/out of the membranes or from one side to the other)|
|pressure increases on Side A|
|pressure increases on Side B|
|sucrose is evenly distributed in the system|
|water and dissolved sucrose flows from Side A to Side B|
|water enters the membrane on Side A|
|water exits the membrane of Side B|
|water flows from Side B to Side A|
Short Answer Questions:
Explain the trapping
hypothesis for symplastic transport of sucrose into the sieve tubes
What is the
function of companion cells?
There are three
major types of companion cells. How are these similar?
Explain how solutes are
loaded in the phloem.
flooding the apoplast surrounding a sieve element with an alkaline buffer
inhibits phloem transport.
contrast how woody plants and herbaceous eudicot plants can be girdled.
Complete the Sentence Question:
Four types of
cells found in the phloem are . . .
Three things that
we learned about the phloem from studies with aphids are . . .
A source is . . .
03/09/2009 � Copyright by SG