Quizes for Plant Sci Exam 2

All of the quizzes after Exam 1

The author states that prairie plants were (almost universally) considered ______________ until only a decade ago.

Weeds

Requirements for fertilizers, pesticides, and water are typically less for prairie plants compared to traditional lawns and gardens.

True

What happened to the vast majority of eastern tallgrass prairie in North America?

it became rich farmland in the late 1800s

The first efforts at prairie restoration occurred in the ____ at _______ by ________

The first efforts at prairie restoration occurred in the 1930s at University of Wisconsin by Aldo Leopold

Improved cultivars are utilized in prairie plantings since they offer the best adaptations to today's conditions.

False

Soil conditions may be enhanced by adding

organic matter

Which of the following shape the final composition of the prairie?

all of the above, including weather, soil conditions, predation by wildfire, and the seeds originally planted

All animal life is encouraged in prairie plantings, not only those located lower on the food chain (such as bees and insects) but also the critters that eat those (rodents, snakes, etc.)

True

What is one of the four groups of herbaceous native perennials listed in the first sentence of the reading?

rushes, wildflowers

Dry stratification involves exposing seed to _____ temperatures for at least ______ days.

Dry stratification involves exposing seed to freezing temperatures for at least 30 days.

Of the species listed for moist stratification,______ has the shortest requirement at____ days, while ____ has the longest at___ days. All of the grasses, sedges and rushes (and most of the wildflowers) listed require___ days.

Of the species listed for moist stratification, lupine has the shortest requirement at 10 days, while iris has the longest at 90 days. All of the grasses, sedges, and rushes (and most of the wildflowers) listed require 30 days.

Which of the following inert materials does the author specifically suggest for moist stratification?

sawdust (oak or pine)

Seeds with hard seed coats often require scarification. The author suggests using ____ to accomplish this.

Seeds with hard seed coats often require scarification. The author suggests using sandpaper to accomplish this.

Seeds that are contained in a fleshy fruit are often treated by _______________ in order to increase germination.

removing the fleshy fruit part over a screen

Most summer-blooming prairie flowers and grasses (including indiangrass and wild ryes) are cool season (or C3) plants.

False

The book describes soil as being made up of particles that come from four sources. Which source includes the living organisms and remains of dead organisms?

organic matter

Soil depletion has been indicated as a reason for the decline of a number of civilizations via the archaeological record.

True

Soil is mainly a product of the climate and parent material, with farming practices having little effect on its status.

False

Adding nitrogen fertilizer can affect the availability of other plant nutrients in the soil system.

True

Energy leaves a farmer’s field as both plant matter that is harvested and as heat.

True

Freezing and expansion of water within cracks of a rock is an example of _____, whereas the interaction of water with parent material in ways that change the mineral composition is [chemical weathering]. Interaction that occurs at the rhizosphere as a result of organic matter decomposition would be ______.

Freezing and expansion of water within cracks of a rock is an example of physical weathering, whereas the interaction of water with parent material in ways that change the mineral composition is [chemical weathering]. Interaction that occurs at the rhizosphere as a result of organic matter decomposition would be chemical weathering.

Some soil water is held too tightly by soil particles to be available to plant roots.

True

Ordering. Put the following pore sizes of soils in order of water-holding capacity (top least, bottom most).

• Large pores (sand)

• medium pores (silt/loam)

• small pores (clay)

The surface area of soil particles found in 1g can vary by as much as a thousandfold.

True

The job of a farmer is generally to try to keep the soil at _____ in terms of water content.

The job of a farmer is generally to try to keep the soil at field capacity in terms of water content.

The oxygen content in soil pore spaces is slightly higher than that of the atmosphere.

False

Clay soils have the highest cation exchange capacity of soils.

True

Clay soils are the best type for plant growth.

False

In areas where the rate of erosion exceeds the rate of soil formation, the depth of the soil _____

In areas where the rate of erosion exceeds the rate of soil formation, the depth of the soil decreases.

Roughly_____of terrestrial organic C is located in soils, with only____ of terrestrial organic C held in the aboveground vegetation and animals that live there.

Roughly 80% of terrestrial organic C is located in soils, with only 20% of terrestrial organic C held in the aboveground vegetation and animals that live there.

Earthworms are incredibly important soil macrofauna (large enough to see with your own eye). In tropical systems these roles may also be filled by_____

ants, termites

Select the appropriate horizon to match with the characteristic.

Partially weathered bedrock or parent material. → ___ horizon,

Concentrated at the top, very dark in color → ___ horizon,

Topsoil. Contains more organic matter than layers below, but less than layer above. → ___ horizon,

Subsoil. Has less organic matter and nutrients than layers above. → ___ horizon

Partially weathered bedrock or parent material. → C horizon,

Concentrated at the top, very dark in color → O horizon,

Topsoil. Contains more organic matter than layers below, but less than layer above. → A horizon,

Subsoil. Has less organic matter and nutrients than layers above. → B horizon

There are____ essential plant macronutrients (needed in large quantities) and____essential micronutrients (needed in small quantities).

There are 6 essential plant macronutrients (needed in large quantities) and 8 essential micronutrients (needed in small quantities).

A ____has a negative charge, and a____has a positive charge. Of the two, ____ are more easily leached (or lost) from soil.

A anion(s) has a negative charge, and a cation(s) has a positive charge. Of the two, anion(s) are more easily leached (or lost) from soil.

Yield potential is typically greater than what farmers achieve in the field.

True

Plant growth may be limited by availability of only one of the essential plant nutrients (all others may be adequate or even in excess, but the one that is present in quantities below that needed by the plant will determine the amount of growth).

True.

The process of organic matter being decomposed and nutrients being released from it that can be used by plants is termed ______

The process of organic matter being decomposed and nutrients being released from it that can be used by plants is termed mineralization

The roots of corn typically go ___deep, whereas those of potatoes grow to a depth of ____, and alfalfa roots to ____.

The roots of corn typically go 3 feet deep, whereas those of potatoes grow to a depth of 2 feet, and alfalfa roots to 5 feet.

Root exudates are thought to play a role in making plant nutrients more available for plants.

True

The _______ are a group of soil microorganisms that secrete proteins that act like glue, helping to bind soil particles and organic matter together.

glomeromycetes

______ is a plant nutrient whose availability is largely impacted by soil pH.

phosphorus

Tropical soils are highly fertile given the warm, humid climate and abundant plant growth.

False

A key ingredient in Terra Preta soils of the tropical Amazon region is ____ (found on average to be 70 times higher than in the surrounding soils).

charcoal

China has both the highest reserves of phosphate rock and the highest production of phosphate fertilizer.

False,It is the number one producer, but its reserve is only 6% of the global supply, far less than many other areas of the globe.

In 1985, ______ as much nitrogen fertilizer was used in the U.S. compared to 1965.

twice

Nitrate (NO₃^-) leaches more easily from soils than ammonium (NH₄⁺).

True

Nitrogen ___ play a role in global climate change as one form is a greenhouse gas.

Nitrogen does play a role in global climate change as one form is a greenhouse gas. it is N₂O that is a greenhouse gas, not N₂ which makes up 78% of the atmosphere.

Plants provide oxygen that Rhizobia bacteria need using a special protein similar to hemoglobin in mammals.

True

Nitrogen is provided in rice paddies by a water fern.

True

Plants in the Brassicaceae (mustard or cabbage family) do not form associations with mycorrhizal fungi.

True

Weed control is achieved in developing countries primarily through

manual labor

Volunteer corn plants are seen as weeds in a field that is being farmed for soybeans.

True

Problematic weeds are disproportionately made up of plants that use the C₃ pathway.

False

Most weed seeds exhibit ____ dormancy.

Most weed seeds exhibit high dormancy.

Ruderals (of which many weeds are classified) tend to be:

Early successional (occupying newly disturbed ground)

Monocrop fields have more unoccupied niches (that can be filled in by weeds) as compared to natural ecosystems or cropping systems that are diverse.

True

Witchweeds of the genus Striga are problematic parasites on ____ crops especially in ____ today. Luckily, they were largely eradicated in ______, through a concerted effort in the 1950s.

Witchweeds of the genus Striga are problematic parasites on Grass crops especially in Africa today. Luckily they were largely eradicated in The Carolinas (USA) through a concerted effort in the 1950s.

Match the correct type of weed control with the examples.

Crop rotation, intercropping, close planting → _____,

Flooding a rice paddy, hoeing → _____l,

Insects or fungi that are pests on the weed species → ______

Crop rotation, intercropping, close planting → cultural,

Flooding a rice paddy, hoeing → mechanical,

Insects or fungi that are pests on the weed species → biological

When cropping systems are less diverse, insect and disease problems become more severe.

True

The mode of action for Glyphosate (Roundup) is:

Inhibition of amino acid biosynthesis

What property of glyphosate makes it less likely to be found in groundwater than some other herbicides?

It strongly binds to soil

A chemical that has a _____ LD₅₀ is more toxic/dangerous to human health.

A chemical that has a lower LD₅₀ is more toxic/dangerous to human health.

Use of a diverse array of weed control measures (such as using different herbicides or using mechanical or cultural control methods) instead of only using one herbicide makes it more difficult for weeds to develop resistance to control measures.

True

The development of Roundup-ready GE crops resulted in the _______ of tillage, thereby leading to the ______ of soil erosion.

The development of Roundup-ready GE crops resulted in the decrease of tillage, thereby leading to the decrease of soil erosion.

_____ are an especially problematic weed species in the US, in part due to ___________

Pigweeds (Amaranthus spp.) are an especially problematic weed species in the US, in part due to being dioecious (having separate male and female plants).

Regulatory hurdles for herbicides are less restrictive now than 50 years ago, so many new herbicides are coming on the market regularly.

False

Most pathogens infect only certain parts of a plant.

True

Match the three important factors of disease in plants with the examples that go with each factor.

Genotype → ______,

Humidity, temperature, plant density → __________,

Mode of introduction, abundance, and genotype → __________

Genotype → Susceptible Plant,

Humidity, temperature, plant density → Disease-favoring Environment,

Mode of introduction, abundance, and genotype → Virulent Pathogen

Name one of the crops that experienced devastating crop losses in the past (see pp.377-378) due to plant disease outbreaks

Corn, Rice

Fungal pathogens responsible for fungal smut diseases in grains become more problematic as farmers save seed and as organic acreage/production increases.

True

Viruses are larger in size and more complex genetically than bacteria

False

Viruses typically need to enter a plant via a wound or insect vector.

True

Unfortunately once a plant has a virus there is no way to propagate it asexually (or vegetatively) to make virus-free plants.

False

Effector proteins are made by the _____ and act on the _______ in a myriad of ways (changing cell wall composition, suppressing immune response, etc.).

Effector proteins are made by the pathogen and act on the plant host in a myriad of ways (changing cell wall composition, suppressing immune response, etc.).

Wilt diseases are problematic only when soils are too dry.

False

Oomycetes used to be classified as ____ but differ in some key ways.

Oomycetes used to be classified as fungi but differ in some key ways.

Many more diseases are known to come from fungi and oomycetes that impact plants as compared to those (from fungi and oomycetes) that impact animals.

True

Rice blast and cereal rusts are both examples of _______ pathogens.

fungal

Insecticides are used not only to control insect pests, but also to control___pathogens.

Insecticides are used not only to control insect pests, but also to control viral pathogens.

% of all grapes and potatoes are treated with fungicides.

95

Pesticides are not used on organic food crops.

False

Match the type of defense with the description of each defense.

cell wall reinforcement following infection →_____,

waxy cuticle → _______,

terpenes and tannins → ______,

production of microbial enzymes following infection →______

cell wall reinforcement following infection → induced,

waxy cuticle → constitutive,

terpenes and tannins → constitutive,

production of microbial enzymes following infection → induced

Systemic acquired resistance refers to the ability of plants to __________their defenses after exposure to a pathogen.

Systemic acquired resistance refers to the ability of plants to heighten/increase their defenses after exposure to a pathogen.

Over the past 50 years,____of all food that could have been harvested is lost to invertebrate herbivores. In tropical countries postharvest losses due to pests can be up to ____.

Over the past 50 years, 15% of all food that could have been harvested is lost to invertebrate herbivores. In tropical countries postharvest losses due to pests can be up to 30%.

An insect that feeds on the roots or leaves of a plant that is grown for the fruit is an example of _____damage.

An insect that feeds on the roots or leaves of a plant that is grown for the fruit is an example of indirect damage.

________herbivores feed on nutrient-rich plant parts (that contain high levels of defense compounds) while________ herbivores feed on less nutritious parts that have lower concentrations of defense compounds.

Specialist herbivores feed on nutrient-rich plant parts (that contain high levels of defense compounds) while Generalist herbivores feed on less nutritious parts that have lower concentrations of defense compounds.

Match the pest type with the way it damages the plant.

Aphids & leafhoppers → ____________

Thrips & mites →_________

Caterpillars, beetle larvae, grasshoppers → _________

Aphids & leafhoppers → Piercing stylets into phloem cells,

Thrips & mites → Piercing stylets into individual cells on surface,

Caterpillars, beetle larvae, grasshoppers → Chewing insects

The book states that__________ are the most numerically abundant pests.

The book states that nematodes are the most numerically abundant pests.

Solarization is the use of __________ to heat up the soil, and can be effective at eliminating both nematodes and______.

Solarization is the use of plastic sheeting/tarps to heat up the soil, and can be effective at eliminating both nematodes and weeds.

The priming effect (that is, a plant’s ability to ramp up its defenses after it has been attacked once by an insect) cannot carry over into its seeds/F2 generation.

False

Many of the legal and illegal drugs used by people are compounds made by plants that are toxic to insects.

True

In the absence of any controls, a single aphid could have________ offspring in one summer (see p.415).

In the absence of any controls, a single aphid could have 1,000,000,000 offspring in one summer (see p.415).

In push-pull systems, the ____ plants are the ones that attract the pest insects, and the______ plants are the ones that repel the pest insects. (These are both separate plant species from the crop plant that is human food.)

In push-pull systems, the pull plants are the ones that attract the pest insects, and the push plants are the ones that repel the pest insects. (These are both separate plant species from the crop plant that is human food.)

Imidacloprid, the most widely used insecticide in the world in the class of _________ . It has been banned in the EU and is detrimental to pollinators.

Imidacloprid, the most widely used insecticide in the world in the class of Neonicotinoids. It has been banned in the EU and is detrimental to pollinators.

One concern with transgenic genetic engineering is that people who are allergic to the crop whose genes are inserted might have a reaction to the crop into which the genes were inserted.

True

The first Bt GE crop to come on market was a_____ but public concern led to its demise. However, Bt-enginnered_____ now makes up over 75% of the crop grown in the U.S.

The first Bt GE crop to come on market was a potato but public concern led to its demise. However, Bt-enginnered corn now makes up over 75% of the crop grown in the U.S.

The use of refugia (adjacent area with non-Bt plants) can slow the evolution of resistance (to Bt) in susceptible insect pests.

True

Thus far there are not documented cases of corn rootworm overcoming challenges to its natural cycle in corn-soybean rotation (see p.431).

False

Genetic engineering of a new crop would be an example of________whereas irrigation would be________.

Genetic engineering of a new crop would be an example of Maximizing yield potential genetically whereas irrigation would be Manipulating the environment.

The presence of proteins needed to manage stress are determined during the first weeks of growth in a plant, meaning if the stress isn’t present then the necessary proteins won’t be.

False