Name: 
 

Ch 23 Roots, Stems and Leaves.


Multiple Choice (Value 20)
Identify the choice that best completes the statement or answers the question.
 

 1. 
If some of the xylem of a young oak tree were destroyed, it would most likely interfere with the tree’s ability to
a.
conduct water to the leaves.
c.
conduct sugars to the roots.
b.
absorb water from the soil.
d.
absorb sunlight.
 

 2. 
The closing of a plant’s stomata will
a.
cause less water to be pulled up from the plant’s roots.
b.
increase transpiration pull.
c.
increase capillary action in the plant’s stem.
d.
cause wilting.
 

 3. 
Which of the following describes the heartwood of a tree?
a.
produces protective layers of cork
b.
old, nonfunctioning xylem
c.
active xylem that transports water and minerals
d.
old, nonfunctioning phloem
 

 4. 
A seed plant is anchored in the ground by its
a.
leaves.
c.
roots.
b.
stems.
d.
trichomes.
 

 5. 
The stomata of leaves are usually open in
a.
darkness if a plant has enough water.
c.
light if a plant has enough water.
b.
light if a plant has too little water.
d.
darkness if a plant has too little water.
 
 
nar001-1.jpg

Figure 23–1
 

 6. 
Figure 23–1 shows cross sections of monocot and dicot
a.
stems.
c.
root hairs.
b.
roots.
d.
leaf veins.
 

 7. 
Which of the following is most likely to be used as a food source?
a.
root with many root hairs
c.
root of a monocot
b.
fibrous root
d.
root of a dicot
 

 8. 
A carrot is a(an)
a.
monocot.
c.
extensive root system.
b.
taproot.
d.
fibrous root.
 

 9. 
Unlike tracheids, vessel elements
a.
are found in phloem.
c.
die before they conduct water.
b.
form a continuous tube.
d.
are found in angiosperms.
 

 10. 
The outer covering of a plant consists of
a.
dermal tissue.
c.
meristematic tissue.
b.
vascular tissue.
d.
ground tissue.
 

 11. 
What type of tissue is the first tissue in a plant seedling?
a.
vascular
c.
meristematic
b.
dermal
d.
ground
 

 12. 
The attraction of water molecules to other molecules is called
a.
capillary action.
c.
cohesion.
b.
transpiration pull.
d.
adhesion.
 
 
nar002-1.jpg

Figure 23–2
 

 13. 
In Figure 23–2, the water pressure in the
a.
guard cells is high.
c.
stoma is high.
b.
guard cells is low.
d.
stoma is low.
 

 14. 
Root pressure
a.
is produced within the cortex of the root.
b.
forces water in xylem downward.
c.
is produced in the vascular cylinder by active transport.
d.
causes a plant’s roots to absorb water.
 

 15. 
Water will move higher in a narrow glass tube than in a wide glass tube because of
a.
pressure.
c.
capillary action.
b.
cohesion only.
d.
adhesion only.
 

 16. 
Vascular tissue in plants consists of
a.
parenchyma and collenchyma cells.
c.
meristem.
b.
xylem and phloem.
d.
epidermal cells.
 

 17. 
Most of the photosynthetic activity in plants takes place in the
a.
guard cells.
c.
xylem.
b.
stomata.
d.
mesophyll.
 

 18. 
Which one of the following statements is true?
a.
The vascular bundles of monocot and dicot stems are continuous from the root’s vascular cylinder.
b.
The tissues in a monocot stem are different from those in a dicot stem.
c.
Xylem and phloem cells of monocots are arranged in a cylinder.
d.
The pith and cortex of dicot stems consist of meristematic cells.
 

 19. 
In many plants, stomata are found only on the lower surface of the leaf.  The most likely explanation for this observation is that
a.
water loss would be less on the shady lower surface than in direct sun.
b.
gas exchange is more efficient from the lower surface.
c.
photosynthesis only occurs in the spongy mesophyll near the bottom of the leaf.
d.
stomata are closer to vascular bundles that bring water into the leaf.
 

 20. 
The movement of sugars in a plant can be explained by
a.
root pressure.
c.
capillary action.
b.
transpiration pull.
d.
the pressure-flow hypothesis.
 

Modified True/False (Value 10)
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
 

 21. 
When plants pump nutrients from their roots to their branches, the roots are the sink. _________________________

 

 22. 
Meristematic tissue produces new cells by mitosis. _________________________

 

 23. 
The thin, flat part of a leaf is called the petiole. _________________________

 

 24. 
When the guard cells of a leaf lose water, the stomata open. _________________________

 

 25. 
A decrease in the active transport of minerals into a root would not cause the root to release water into the soil. _________________________

 

 26. 
The secondary growth of a dicot stem results from cell divisions in the stem’s vascular cambium and xylem. _________________________

 

 27. 
In plants, the opening and closing of stomata balance water loss with the need for carbon dioxide. _________________________

 

 28. 
The principal organs in which plants carry out photosynthesis are leaves. _________________________

 

 29. 
In a tree, the heartwood increases in width over time. _________________________

 

 30. 
The vascular bundles in a dicot stem are arranged randomly. _________________________

 

Completion (Value 5)
Complete each statement.
 

 31. 
As the relative concentration of mineral ions in a root’s epidermal cells increases, the relative concentration of water molecules ____________________.
 

 
 
nar003-1.jpg

Figure 23–3
 

 32. 
Figure 23–3 shows a cross section of a(an) ____________________.
 

 

 33. 
Stomata open into the _________________________ layer of a leaf.
 

 
 
nar001-1.jpg

Figure 23–1
 

 34. 
In Figure 23–1, B is pointing to _________________________.
 

 

 35. 
The phloem cells called ___________________ are arranged end to end to form a long pipeline.
 

 

Short Answer (Value 10)
 

 36. 
How is the function of a stem similar to that of a root?
 

 37. 
Contrast the growth of fibrous roots and taproots in soil.
 

 38. 
Contrast the flow of materials in xylem and phloem.
 

 39. 
Contrast the arrangement of vascular bundles in monocot stems and dicot stems.
 

 40. 
What do roots absorb from the soil?
 



 
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