Name: 
 

Chapter 37



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

Which two elements make up more than 90% of the dry weight of plants?
a.
carbon and nitrogen
b.
oxygen and hydrogen
c.
nitrogen and oxygen
d.
oxygen and carbon
e.
carbon and potassium
 

 2. 

In the nutrition of a plant, which element is classified as a macronutrient?
a.
zinc
b.
chlorine
c.
calcium
d.
molybdenum
e.
manganese
 

 3. 

Which of the following best describes the general role of micronutrients in plants?
a.
They are cofactors in enzymatic reactions.
b.
They are necessary for essential regulatory functions.
c.
They prevent chlorosis.
d.
They are components of nucleic acids.
e.
They are necessary for the formation of cell walls.
 

 4. 

What is meant by the term chlorosis?
a.
the uptake of the micronutrient chlorine by a plant
b.
the formation of chlorophyll within the thylakoid membranes of a plant
c.
the yellowing of leaves due to decreased chlorophyll production
d.
a contamination of glassware in hydroponic culture
e.
release of negatively charged minerals such as chloride from clay particles in soil
 

 5. 

What soil(s) is(are) the most fertile?
a.
humus only
b.
loam only
c.
silt only
d.
clay only
e.
both humus and loam
 
 
The figure below shows the results of a study to determine the effect of soil air spaces on plant growth. Use these data to answer the following questions.

chpt_37_files/i0070000.jpg
 

 6. 

The best conclusion from the data in the figure above is that the plant
a.
grows best without air in the soil.
b.
grows fastest in 5 to 10% air.
c.
grows best in air levels above 15%.
d.
does not respond differently to different levels of air in the soil.
e.
would grow to 24 grams in 40% soil air.
 

 7. 

Nitrogen fixation is a process that
a.
recycles nitrogen compounds from dead and decaying materials.
b.
converts ammonia to nitrate.
c.
releases nitrate from the rock substrate.
d.
converts nitrogen gas into ammonia.
e.
both A and B
 

 8. 

Why is nitrogen fixation such an important process?
a.
Nitrogen fixation can only be done by certain prokaryotes.
b.
Fixed nitrogen is most often the limiting factor in plant growth.
c.
Nitrogen fixation is very expensive in terms of metabolic energy.
d.
Nitrogen fixers are sometimes symbiotic with legumes.
e.
Nitrogen-fixing capacity can be genetically engineered.
 

 9. 

Among important crop plants, nitrogen-fixing root nodules are most commonly an attribute of
a.
corn.
b.
legumes.
c.
wheat.
d.
members of the potato family.
e.
cabbage and other members of the brassica family.
 

 10. 

A woodlot was sprayed with a fungicide. What would be the most serious effect of such spraying?
a.
a decrease in food for animals that eat mushrooms
b.
an increase in rates of wood decay
c.
a decrease in tree growth due to the death of mycorrhizae
d.
an increase in the number of decomposing bacteria
e.
both A and B
 

 11. 

Dwarf mistletoe grows on many pine trees in the Rockies. Although the mistletoe is green, it is probably not sufficiently active in photosynthesis to produce all the sugar it needs. The mistletoe also produces haustoria. Thus, dwarf mistletoe growing on pine trees is best classified as
a.
an epiphyte.
b.
a nitrogen-fixing legume.
c.
a carnivorous plant.
d.
a symbiotic plant.
e.
a parasite.
 

 12. 

What are epiphytes?
a.
aerial vines common in tropical regions
b.
haustoria used for anchoring to host plants and obtaining xylem sap
c.
plants that live in poor soil and digest insects to obtain nitrogen
d.
plants that grow on other plants but do not obtain nutrients from their hosts
e.
plants that have a symbiotic relationship with fungi
 

 13. 

Carnivorous plants have evolved mechanisms that trap and digest small animals. The products of this digestion are used to supplement the plant's supply of
a.
energy.
b.
carbohydrates.
c.
lipids and steroids.
d.
minerals.
e.
water.
 



 
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