201 - _____ = _____ / 191 = 73.4%

Biology 332
Spring 2000

Exam II

Name___________________

This test is designed to assess your learning about plant anatomy and associated physiology.

In the space below, make a sketch of a mesophytic dicot leaf cross-section. You need to show only a few cells in each area of the cross section. Label this sketch with the name and major function of each labeled area. 24 points

Any 12 of the following:

If the leaf above were to be changed to a xerophytic (C-4) monocot leaf cross-section, what would be different? List each area of the leaf above that would be changed and then tell how it would be different (structurally or functionally). 12 points

Any 6 of the following:

If the leaf you sketched were to be changed to a hydrophytic leaf cross-section, what would be different? List each area of the leaf above that would be changed and then tell how it would be different (structurally or functionally). 10 points

Any 5 of the following:


How does a leaf on the sunny side of a tree differ from one on the shaded side? 10 points

The leaf in the sun...

Any 5 of the following:

Aside from photosynthesis, what is the other major function of a leaf? 2 points

evaporative cooling/associated transpiration "pull"

In the space below, make a sketch of a herbaceous dicot stem cross-section. You need to show only a few cells in each area of the cross section. Label this sketch with the name and major function of each labeled area. 14 points

Any 7 of the following:

If the stem you sketched above were changed to a monocot stem, what would be the three major differences? 6 points

Any 3 of the following:


The secondary plant body has two sections.... 14 points
    For the vascular section:

Name the tissue responsible for producing this section. cambium

Name the sclerenchyma-type derivative in this section. 2° xylem

Name the parenchyma-type derivative in this section. 2° phloem

Which derivative is produced most abundantly? 2° xylem

Does that derivative mature toward the inside or the outside of the meristem? inside

What is the major wall additive in these abundant derivatives? lignin

What is the common name for the layers of these abundant derivatives? growth rings/wood

    For the dermal section:
Name the tissue responsible for producing this section. cork cambium (pericycle, cortex)

Name the sclerenchyma-type derivative in this section. cork

Name the parenchyma-type derivative in this section. phelloderm

Which derivative is produced most abundantly? cork

Does that derivative mature toward the inside or the outside of the meristem? outside

What is the major wall additive in these abundant derivatives? suberin

What is the technical name for this dermal section? periderm

The two meristems of the secondary plant body are composed of three quite-different cell types (in total). Describe the shape of the meristematic cells you observed in each of the two meristems. 6 points
fusiform initial-elongate, tapered at ends

ray initial-cubical

cork cambium initial-cubical

What is the product when a fusiform initial divides by laying down a new wall in the... 3 points

radial plane? fusiform initial

tangential plane? secondary xylem or phloem

transverse plane? ray initial

How does a mature tree get sugar and amino acids from the phloem to the pith? Where do the responsible conductive cells come from...be specific! Besides conduction direction, how do these cells differ from the other cells in that region between phloem and pith? 8 points

It goes from phloem sieve tube to phloem ray parenchyma, through the cambium, through xylem ray parenchyma, to the pith. The cells handling this pathway are mostly xylem parenchyma conducting inwardly rather than upwardly in sclerenchyma type cells. The xylem and phloem ray parenchyma cells elongate in lateral dimensions.


In the space below, make a sketch of a monocot root cross-section. You need to show only a few cells in each area of the cross section. Label this sketch with the name and major function of each labeled area. 14 points
Any 7 of the following:

How would your sketch above change if I had asked you for a herbaceous dicot root cross section? 6 points

How would your sketch above change if I had asked you for a mature woody dicot root cross section? 10 points
Any 5 of the following:

In the remaining space, sketch a longitudinal section of a root tip. Show and label all appendages, all tissue layers, all zones, etc. For each area, tell what it does or what it becomes. 22 points
Any 11 of the following:


How would you demonstrate that... 4 points each

xylem conducts water and minerals through the stem?
sever a plant shoot and stand it in a 1% Eosin Y solution
look for pink stripes up the stem and pink veins in the leaf, check for pink xylem with sections

endodermis is involved in selective uptake?
flood a rooted plant with a 1% Eosin Y solution
after sufficient time for severed shoot to turn pink, uproot plant
check for Eosin Y penetration in root sections
evaporation occurs from leaves?
continue observation of severed shoot in Eosin Y
look for inter-vein areas of blade to turn very dark red as water is evaporated

a plant organ grows only in certain areas but not others?
mark organ evenly with Sharpie marker
measure changes in spacing of the marks after growth in growing areas

seedlings use starch to grow but mature plants store starch?
make cross sections of mature and immature stems, or from base to apex on a single stem, stain starch black with iodine stain
if seedlings use up all their imported photosynthate, there will be no black deposits; if mature stems store starch you would expect to find black deposits in the cortex just outside the phloem of vascular bundles.

a leaf carries out photosynthesis?
aspirate leaves in a bicarbonate buffer to infuse them...they will sink...then place in bright light
if photosynthesis occurs, oxygen will be made and the leaves will refloat...
to be sure, after they refloat move them to darkness and respiration should use up the oxygen trapped in gas spaces and the leaves should sink.

the duration of each part of mitosis?
observe a section of a meristematic zone in a field of the microscope, count the total number of cells in the field, count the number of cells in each phase of mitosis, express the number in a phase as a decimal of the total
the relative duration is determined by comparing these percentages among the phases

roots carry out respiration?
pack the roots in a small test tube, with a paper separator include a few pellets of NaOH or KOH to absorb CO2, plug the tube with a one-hole stopper fitted with a calibrated micropipette
the uptake of oxygen can be observed by placing a drop of ink at the end of the pipette and observing the changes in the volume of gas inside the container.

xylem maturation is endarch?
make a longisection through the organ, stain with phloroglucinol HCl or toluidine blue
look for xylem cells with annular or helical wall thickenings (protoxylem) and compare their position to pitted or just-maturing xylem cells (metaxylem)
if protoxylem is closer to the pith and metaxylem is closer to the epidermis, then xylem maturation is endarch

a leaf is compound?
determine what is the extent of a leaf; petioles have an axillary bud in their axil, then count the blades on the petiole
if there is more than one blade per petiole (rachis) then it is compound



This page © Ross E. Koning 1994.

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Koning, Ross E. "Exam 2 2000". Plant Physiology Website. 1994. http://koning.ecsu.ctstateu.edu/plant_biology/ex2.00.html (your visit date).

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