Chemistry for Changing Times, 14e (Hill/McCreary)
Chapter 20 Chemistry Down on the Farm . . .
20.1 Multiple Choice Questions
1) Green plants are the ultimate source of our food. Which of the following statements about the source
of the raw materials that plants incorporate into food is NOT correct?
A) Sunlight provides the plant with energy to convert carbon dioxide and water into sugars.
B) Plants obtain carbon, hydrogen and oxygen from air and water.
C) Plants obtain molecular oxygen from the air and incorporate it into sugars.
D) Plants obtain nutrients such as trace metals from the soil.
2) Which of the following statements about early societies is NOT true?
A) One unit of human energy could produce up to ten units of food energy.
B) Most of the energy came from renewable resources.
C) Early agricultural practices rapidly depleted nutrients in the soil.
D) A portion of the energy from food was invested in shelter and clothing.
3) Which fertilizer is also an explosive?
A) NBr3
B) NH4NO3
C) NaI
D) Sr3(PO4)2
2
4) An early source of phosphorus for agriculture was
A) urea.
B) bird droppings.
C) superphosphate.
D) all of the above
5) Plants incorporate phosphorus into
A) amylopectin.
B) RNA.
C) bacteria.
D) phosphoric acid.
6) The conversion of phosphate rock and bone to “superphosphate” was significant because it
A) increased the phosphorus content of the rock or bones.
B) made the material more soluble.
C) incorporated phosphorus from the atmosphere.
D) did all of the above.
7) Sulfur is needed by plants for
A) nitrogen fixation.
B) nucleic acid synthesis.
C) amino acid and protein synthesis.
D) maintaining electrical neutrality.
8) Uptake of potassium ions from the soil by a plant requires the loss of a hydronium ion from the plant.
The soil, therefore, becomes
A) more acidic.
B) more basic.
C) neutral.
D) nitrogen rich.
9) The usual chemical form of potassium in commercial fertilizers is as
A) potassium bromide.
B) potassium phosphite.
C) potassium chloride.
D) potassium carbonate.
10) A 5-15-20 fertilizer has what percentage of N?
A) 5%
B) 15%
C) 20%
D) none of these
11) Nitrogen must be “fixed” to convert it into a form which plants can use. Which of the following forms
of nitrogen CANNOT be used by plants?
A) N2
B) NH3
C) NH4NO3
D) (NH4)2SO4
12) The Haber process results in
A) the conversion of N2 and H2 to NH3.
B) the fixation of N2 to form NO3–.
C) the combination of bone phosphate with sulfuric acid to form superphosphate.
D) the mining of potassium chloride deposits by using an environmentally friendly method.
13) Which of the following statements about humus is NOT correct?
A) Humus aids in water retention.
B) Humus both increases the loss of nutrients through leaching and increases erosion.
C) Humus is a dark-colored material consisting of partially decayed plant or animal matter.
D) Humus provides a good environment for earthworms.
14) The three primary plant nutrients are
A) phosphorus, nitrogen and calcium.
B) phosphorus, potassium and nitrogen.
C) magnesium, phosphorus and nitrogen.
D) calcium, potassium and magnesium.
15) Of the following pesticides and their LD50s (milligrams of pesticide/kg of rat) in rats, which pesticide
is most toxic to rats?
A) pyrethrins (200-2600)
B) nicotine (230)
C) lindane (91)
D) aldicarb (1)
16) The LD50 for aldicarb in rats is 1 mg per kg of body mass. Assuming that the LD50 is the same for
humans, how much aldicarb would it take to kill an 80 kg person?
A) 2 mg
B) 80 mg
C) 160 mg
D) 1600 mg
17) DDT is concentrated in living organisms because it is
A) water soluble.
B) fat soluble.
C) synthetic.
D) synthesized in the liver.
18) DDT is particularly harmful to birds because it
A) interferes with digestion.
B) interferes with calcium metabolism and egg production.
C) accumulates in the heart.
D) is fat insoluble.
6
19) DDT was NOT effective against
A) foxes.
B) grapevine pests.
C) lice.
D) mosquitos.
20) In 1957, Clear Lake in California was sprayed with DDT such that the water contained 0.02 ppm of
DDT. After a period of time, fish in the lake were found to have DDT levels as high as 2000 ppm. This is
an example of
A) biological magnification of DDT.
B) species resistance to DDT.
C) natural decomposition of DDT.
D) species tolerance of DDT.
21) In 1957, Clear Lake in California was sprayed with DDT such that the water contained 0.02 ppm of
DDT. After a period of time, large fish in the lake were found to have DDT levels as high as 2000 ppm.
Which of the following animals would be predicted to have DDT levels > 2000 ppm?
A) algae
B) hummingbirds
C) small fish
D) eagles
22) A phosphorus-containing pesticide is
A) aldicarb.
B) diazinon.
C) methoprene.
D) paraquat.
23) Organophosphorus pesticides are generally less ________ than DDT.
A) potent
B) insect resistant
C) persistent
D) fat soluble
24) Which is classified as a narrow spectrum pesticide?
A) DDT
B) an organophosphorus pesticide
C) a carbamate
D) lead arsenate
25) Carbaryl is one type of carbamate pesticide. A major problem associated with carbaryl is its
A) persistence in the environment.
B) toxicity towards honeybees.
C) broad range of action.
D) interference with egg production in birds.
26) Which of the following types of compounds do NOT accumulate in fatty tissues?
A) carbamates
B) chlorinated hydrocarbons
C) organic phosphorus compounds
D) All of the above accumulate in fatty tissues.
27) Which of the following types of compounds are narrow-spectrum insecticides?
A) carbamates
B) chlorinated hydrocarbons
C) organic phosphorus compounds
D) None of the above is a narrow-spectrum insecticide.
28) A worker at an experimental agricultural station spills a substance on her lab coat. The next morning
her lab coat is covered with sex crazed moths. The spilled substance was probably
A) fertilizer.
B) DDT.
C) juvenile hormone.
D) a pheromone.
29) Pheromones are
A) chemical substances excreted by insects.
B) a class of organophosphorus pesticides.
C) natural insecticides produced by plants.
D) human sex hormones.
30) Identify the compound that is NOT a pesticide.
A) carbaryl.
B) atrazine.
C) cryolite.
D) boric acid.
31) An experimental pesticide with a very specific action that is harmless to humans and other animals
and completely biodegradable is
A) diazinon.
B) parathion.
C) chlorpyrifos.
D) a viral pesticide.
32) Juvenile hormones are chemicals
A) that speed up the maturation of insects.
B) that slow down the maturation of insects.
C) that halt maturation of insects.
D) that kill juvenile insects before they mature.
33) Which of the following does NOT involve using a biological insect control method?
A) releasing sterile males into the wild
B) treating insects with juvenile hormones
C) using organic phosphorus compounds
D) attracting insects with pheromones
34) Which of the following is the least expensive method of controlling insects?
A) carbamates
B) juvenile hormones
C) pheromones
D) sterile insects
10
35) Which of the following would be a characteristic of a green chemistry pesticide?
A) biodegradable
B) minimal effect on the environment
C) toxic only to a specific pest
D) all of the above
36) Which insecticide was first used by Allied soldiers to combat lice, ticks and mosquitos during World
War II?
A) DDT
B) carbofuran
C) nicotine
D) acetic acid
37) Organophosphates and chlorinated hydrocarbons have both been used as insecticides. Which of the
following statements about these two types of compounds is true?
A) Chlorinated hydrocarbons break down faster in the environment than organophosphates do.
B) Organophosphates break down faster in the environment than chlorinated hydrocarbons do.
C) Chlorinated hydrocarbons and organophosphates both break down very quickly in the environment
and at about the same rate.
D) Chlorinated hydrocarbons and organophosphates both break down very slowly in the environment
and at about the same rate.
38) Dioxin is a chemical contaminant produced during the manufacture of
A) 2,4,5 –T.
B) aldicarb.
C) atrazine.
D) diazinon.
39) Which of the following is an herbicide?
A) 2,4-D
B) parathion
C) carbaryl
D) diazinon
40) A compound that causes leaves to fall off plants is a(n)
A) insecticide.
B) defoliant.
C) herbicide.
D) pesticide.
41) Paraquat is an example of a ________ herbicide.
A) narrow spectrum
B) broad spectrum
C) preemergent
D) postemergent
42) All of the following are natural organic herbicides EXCEPT
A) acetic acid.
B) gluten meal.
C) bone meal.
D) eugenol, an ingredient in oil of cloves.
43) In a modern society, approximately what percentage of human energy is used to produce food?
A) 10%
B) 25%
C) 45%
D) 65%
44) All of the following are goals of sustainable agriculture EXCEPT
A) farm profitability.
B) maintaining a healthy environment.
C) not using commercial fertilizers.
D) social and economic equity.
45) Which of the following nanoscale applications have been used for fertilizer and micronutrients?
A) distribution into ground that has been worked to have nano-sized pores.
B) polystyrene nanoparticles
C) zeolites
D) zirconium oxide
46) Which of the following statements best describes the land available world-wide for increasing
farming and food production?
A) Only about 50% of the world’s arable land is currently being used for agriculture.
B) The amount of land available for growing food is decreasing, because some land has been converted to
producing crops that can be used to make biofuels.
C) Increased efficiency will allow us to quadruple our food production in the next 25 years.
D) Converting more acres to organic farming practices will result in a large increase in food production.
13
47) If the world’s population is growing at the rate of 1.5% per year, how many years will it take for the
world’s population to double?
A) 16
B) 32
C) 48
D) 64
48) The ultimate solution to the Malthusian dilemma is
A) ever increasing natural resources production.
B) population control.
C) better pesticides.
D) more land available for farming.
1) The three primary plant nutrients found in fertilizers are nitrogen, magnesium and silicon.
2) More nitrogen is fixed by lightning than by bacteria.
3) Using fresh manure as fertilizer for fruits and vegetables can result in food-borne illnesses.
4) As the LD50 of a substance decreases, the toxicity of the substance decreases.
5) Juvenile hormones act by speeding up insect development.
6) Praying mantises and ladybugs are predatory insects and will destroy many garden pests.
7) A very successful approach to limiting insects is to breed insect-resistant plants.
8) The new spinosad pesticides utilize an active ingredient which is derived from naturally occurring
bacteria and is harmful to the nervous system of targeted insects.
9) Herbicides are chemicals that are used to kill weeds.
10) Dioxin contaminants in Agent Orange have been linked to birth defects.
11) A preemergent herbicide should be applied to fields when seedlings are at least six inches high.
12) Atrazine disrupts normal estrogen function and has been linked to sexual abnormalities in frogs.
13) Organic farming uses no synthetic fertilizers or pesticides.
14) In modern societies, 70% of human energy is used to produce food.
15) Nano materials have been thoroughly tested and shown to be safe, because they are too small to be
absorbed into cells
16) Each U.S. farm worker currently produces enough food for 105 people.
17) Over 10% of the earth’s population is seriously malnourished.
18) There is still much arable land on Earth that has not been used for cultivation.
1) An early source of phosphorus for agriculture was ________.
2) What does 20-5-15 on a bag of fertilizer mean?
3) As the LD50 of a substance decreases, the toxicity of the substance ________.
20.4 Essay Questions
1) Explain the biological magnification of DDT and its impact on animal life.