Biology 112 - CHapter 38 Nutrition

Select all that are likely to exhibit a direct increase in growth as a result of the leaching of minerals from the soil by a heavy rainfall

Algae Cyanobacteria Aquatic plants

Select all the forms of nitrogen that can be taken up directly by plants.

Ammonium ion Nitrate from microorganisms in the soil Ammonia applied as a fertilizer

Select all that will experience enhanced growth following excess application of fertilizers and leaching into aquatic habitats

Aquatic plants Algae

Why is humus a beneficial component of soil?

Binds mineral nutrients to improve fertility Soft consistency fosters root growth Lessens erosion

______ are chemical elements that are needed by plants for survival.

Essential elements

Select all examples of plant-bacterial symbioses.

Ferns and cyanobacteria Alders and actinobacteria Peanuts and rhizobia

What is the name for the material that comes in organic and inorganic forms and can compensate for deficiencies in soil organic matter or mineral content?

Fertilizer

Select all that affect soil horizon composition and thickness.

History of human impact Climate and vegetation Bedrock type

Select all functions of nitrogen.

It is used to synthesize amino acids and nucleotides. It is used in the synthesis of alkaloids.

Which of the following best explains how lush forest trees can grow on thin, infertile soils?

Mycorrhizal fungi rapidly collect soil minerals released from decaying organisms and transport them directly to plant roots

In both biological and industrial nitrogen fixation, nitrogen is converted from _______ to ______

N2; NH3

Which nutrient is limiting to crops due to the role it plays in synthesis of amino acids, nucleotides, and alkaloids?

Nitrogen

In mycorrhizal associations, what does the plant provide to the fungus, and what does the fungus provide to the plant?

Plant provides organic food; fungus provides mineral nutrients

Select all of the ways that plants adapt to shading.

Production of more total chlorophyll, Production of thin leaves

What organisms provide most of the fixed nitrogen in soils by carrying out biological nitrogen fixation?

Prokaryotes

When legume plants die, what do they generate?

Soil organic matter that is rich in nitrogen

How do fungal mycelia relate to plant nutrition?

The mycelia of mycorrhizal fungi improve water and mineral uptake in the plant host.

In plant-bacterial symbioses:

The plant provides organic compounds and the bacteria provide fixed nitrogen

Which of the following is a soil feature that enhances plant growth?

The presence of humus

Which of the following is true about mycorrhizal associations?

The soil fungus obtains organic food from the plant, and the plant obtains water and mineral nutrients from the fungus.

Select all true statements about inorganic fertilizers.

They are easily leached from the soil during a heavy rainfall. They are immediately useful for plants.

Select all true statements about rhizobia.

They live within plant cells They are prokaryotic They fix nitrogen

Select all functions of water in plants:

Transport of solutes Source of hydrogen for photosynthesis

Select all compounds that parasitic plants require from host plants

Water Sugar Minerals

Where do rhizobia typically reside?

Within root cells of legumes

To study the mineral elements required for plant growth, scientists often grow plants in a water solution, a process called

a hydroponics system

What form of nitrogen can be used directly by plants to build amino acids?

ammonia

Although light provides the energy for plant photosynthesis, most plant dry mass originates from

carbon dioxide

What is the source of most plant dry mass?

carbon dioxide

Atmospheric carbon dioxide levels:

do not reach levels that saturate plant photosynthesis

Micronutrients are elements that are needed in plants at concentrations equal to or:

equal to or less than 0.1 g/kg of plant dry mass

Chemical elements that are required by plants and play many roles in plant metabolism are called ________ elements.

essential

Soil additions that enhance plant growth by providing essential elements are called

fertilizer

Large areas in the Gulf of Mexico called "dead zones" have microbial populations that decompose algal populations and deplete oxygen from the water, suffocating animal life. What type of application, when applied in excess, contributes to these "dead zones"?

fertilizers

The process by which atmospheric nitrogen gas is combined with hydrogen to produce ammonia is referred to as nitrogen

fixation

In symbioses between plants and bacteria, the microorganisms provide the plants with a much higher supply of ______ than the plants could obtain from most soils.

fixed nitrogen

Soil ________ are layers within a soil profile that are parallel to the soil surface.

horizons

Vegetation, climate, history of human impact, and bedrock type are all factors that affect the composition and thickness of soil __________.

horizons

Visible layers in the soil are called soil

horizons

The nitrogen in inorganic fertilizers is produced by __________ nitrogen fixation.

industrial

Heavy rainfall can reduce the fertility of soils by _________ large amounts of nutrients from them.

leaching

Green plants extract _________ energy from the sun, while animals extract chemical energy from organic compounds

light

Carnivorous plants consume insects to allow them to survive in ______ environments.

low-nitrogen

Elements that are required in large amounts (> 1 g/kg dry plant matter) are known as

macronutrients

Elements that are found in amounts less then 0.1 g/kg of plant dry mass are known as ________, or trace elements.

micronutrients

In a hydroponics study, scientists observe chlorosis in one of the treatments. This is a sign of:

mineral deficiency

Mycorrhizae are important for mineral uptake in tropical forests because:

minerals leach easily due to frequent rains

Compared to organic fertilizers, inorganic fertilizers release nutrients:

more rapidly

Due to extensive ______ that fungi extend in the soil, mycorrhizae provide for an efficient way for plants to take up water and nutrients from a much larger volume of soil.

mycelia

Symbiotic associations between a fungus and a plant in which the fungus provides the plant with increased ability for water and mineral uptake and the plant provides the fungus with organic food molecules are called

mycorrhizae

Symbiotic associations between the roots of a plant and fungi are known as

mycorrhizae

Carnivorous plants prey on animals as a source of:

nitrogen

In nature, legume plants are important sources of fixed ________ for other plants

nitrogen

In nitrogen fixation, ______ is converted into ______. Multiple choice question.

nitrogen gas; ammonia

Carbon dioxide is taken up by growing plants, and the carbon is a component of all organic molecules in the plant. Therefore, carbon is considered to be an essential plan

nutrient

Dodder and witchweed are prominent examples of plants that are completely ________

parasitic

Major examples of ______ are dodder and witchweed.

parasitic plants

Which of the following most accurately describes carnivorous plants?

photosynthetic autotrophs

Carnivorous plants are _________ autotrophs that supply their own organic compounds; prey animals are primarily sources of ___________.

photosynthetic; nitrogen

Stomata are:

pores in the plant epidermis that allow for CO2 absorption

Biological nitrogen fixation is carried out by

prokaryotes exclusively

The proteobacteria that live within root cells or legumes and fix nitrogen are called

rhizobia

Rhizobia live within the _________ cells of wild and cultivated legumes, forming legume-rhizobia symbiosis

root

Most plants obtain CO2 gas from the atmosphere by absorption through pores in the epidermis called

stomata

Under dry conditions, carbon dioxide can be a limiting factor for photosynthesis because:

stomata close to prevent water loss

In plants, chemical energy for metabolism comes from organic molecules that are:

synthesized using light energy

Plants adapted to shade typically have a ______ mesophyll layer, with ______ air spaces than do sun leaves.

thinner; more

Which nutrient is the source of most of the hydrogen atoms and some of the oxygen atoms in organic compounds?

water

Parasitic plants, such as Dodder can be devastating to crop production. Dodder will deprive host plants of _________, _________ , and organic compounds.

water, minerals

Select all major nutrients that plants must take in for growth.

water, nitrogen, potassium, carbon dioxide

The physical and chemical breakdown of rock is called _____________, while a process called erosion is when soil is washed away by water or blown away by wind.

weathering

Which of the following processes contributes to the mineral content of soils?

weathering