Deck 20: Chemistry Down on the Farm

Question 1

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.

Answer 1

biological magnification of DDT.

Question 2

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)

Answer 2

aldicarb (1)

Question 3

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.

Answer 3

Early agricultural practices rapidly depleted nutrients in the soil.

Question 4

An early source of phosphorus for agriculture was

A)urea.
B)bird droppings.
C)superphosphate.
D)all of the above

Question 5

Plants incorporate phosphorus into

A)amylopectin.
B)RNA.
C)bacteria.
D)phosphoric acid.

Question 6

Which fertilizer is also an explosive?

A)NBr₃
B)NH₄NO₃
C)NaI
D)Sr₃(PO₄)₂

Question 7

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.

Question 8

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.

Question 9

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

Question 10

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.

Question 11

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.

Question 12

The usual chemical form of potassium in commercial fertilizers is as

A)potassium bromide.
B)potassium phosphite.
C)potassium chloride.
D)potassium carbonate.

Question 13

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

Question 14

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.

Question 15

A 5-15-20 fertilizer has what percentage of N?

A)5%
B)15%
C)20%
D)none of these

Question 16

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.

Question 17

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.

Question 18

DDT was NOT effective against

A)foxes.
B)grapevine pests.
C)lice.
D)mosquitos.

Question 19

Sulfur is needed by plants for

A)nitrogen fixation.
B)nucleic acid synthesis.
C)amino acid and protein synthesis.
D)maintaining electrical neutrality.

Question 20

DDT is concentrated in living organisms because it is

A)water soluble.
B)fat soluble.
C)synthetic.
D)synthesized in the liver.

Question 21

Identify the compound that is NOT a pesticide.

A)carbaryl.
B)atrazine.
C)cryolite.
D)boric acid.

Question 22

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

Question 23

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.

Question 24

Organophosphorus pesticides are generally less ________ than DDT.

A)potent
B)insect resistant
C)persistent
D)fat soluble

Question 25

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.

Question 26

Which of the following is the least expensive method of controlling insects?

A)carbamates
B)juvenile hormones
C)pheromones
D)sterile insects

Question 27

Which is classified as a narrow spectrum pesticide?

A)DDT
B)an organophosphorus pesticide
C)a carbamate
D)lead arsenate

Question 28

Pheromones are

A)chemical substances excreted by insects.
B)a class of organophosphorus pesticides.
C)natural insecticides produced by plants.
D)human sex hormones.

Question 29

Which of the following is an herbicide?

A)2,4-D
B)parathion
C)carbaryl
D)diazinon

Question 30

A compound that causes leaves to fall off plants is a(n)

A)insecticide.
B)defoliant.
C)herbicide.
D)pesticide.

Question 31

A phosphorus-containing pesticide is

A)aldicarb.
B)diazinon.
C)methoprene.
D)paraquat.

Question 32

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

Question 33

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.

Question 34

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

Question 35

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.

Question 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

Question 37

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.

Question 38

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.

Question 39

Dioxin is a chemical contaminant produced during the manufacture of

A)2,4,5 -T.
B)aldicarb.
C)atrazine.
D)diazinon.

Question 40

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.

Question 41

Dioxin contaminants in Agent Orange have been linked to birth defects.

Question 42

Praying mantises and ladybugs are predatory insects and will destroy many garden pests.

Question 43

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.

Question 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.

Question 45

Herbicides are chemicals that are used to kill weeds.

Question 46

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.

Question 47

Using fresh manure as fertilizer for fruits and vegetables can result in food-borne illnesses.

Question 48

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

Question 49

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.

Question 50

The three primary plant nutrients found in fertilizers are nitrogen,magnesium and silicon.

Question 51

Paraquat is an example of a ________ herbicide.

A)narrow spectrum
B)broad spectrum
C)preemergent
D)postemergent

Question 52

Juvenile hormones act by speeding up insect development.

Question 53

More nitrogen is fixed by lightning than by bacteria.

Question 54

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

Question 55

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.

Question 56

In a modern society,approximately what percentage of human energy is used to produce food?

A)10%
B)25%
C)45%
D)65%

Question 57

A very successful approach to limiting insects is to breed insect-resistant plants.

Question 58

Atrazine disrupts normal estrogen function and has been linked to sexual abnormalities in frogs.

Question 59

A preemergent herbicide should be applied to fields when seedlings are at least six inches high.

Question 60

As the LD₅₀ of a substance decreases,the toxicity of the substance decreases.

Question 61

What does 20-5-15 on a bag of fertilizer mean?

Question 62

Organic farming uses no synthetic fertilizers or pesticides.

Question 63

Over 10% of the earth's population is seriously malnourished.

Question 64

Nano materials have been thoroughly tested and shown to be safe,because they are too small to be absorbed into cells

Question 65

Each U.S.farm worker currently produces enough food for 105 people.

Question 66

Explain the biological magnification of DDT and its impact on animal life.

Question 67

An early source of phosphorus for agriculture was ________.

Question 68

There is still much arable land on Earth that has not been used for cultivation.

Question 69

As the LD₅₀ of a substance decreases,the toxicity of the substance ________.

Question 70

In modern societies,70% of human energy is used to produce food.