Name ___________________________ Date ___________________________ Biology Ch 3 NTWS 3-1 What Is Ecology? Interactions and Interdependence

• ______________ is the scientific study of interactions among organisms and between ______________ and their ______________.

• The largest environment in which living organisms can be found is called the ______________.

• It extends 8 km above Earth’s surface to about 11 km below the surface of the ocean.

• Interactions within the biosphere produce a ______________ of ______________ between organisms and the environment in which they live.

• Earth has an ever-changing, or ______________, ______________. Levels of Organization

• To understand relationships within the biosphere, ecologists ask questions about events and organisms that range in complexity from a single ______________ to the entire ______________.

Ecological Methods

• Regardless of the tools they use, scientists conduct modern ecological research using three basic approaches: ______________, ______________, and ______________. All of these approaches rely on the application of ______________ ______________ to guide ecological inquiry.

3-2 Energy Flow

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Chemosynthesis

Deep Sea Vents Hot Springs Tidal Marshes

Feeding Relationships

• Energy flows through an ecosystem in ______________ direction, from the ______________, or ______________ ______________, to ______________ and then, to various ______________.

• This energy is passed along in a series of steps in which organisms eat or are eaten.

• This is called a ______________ ______________. Food Webs

• A food web is a ______________ of food chains that ______________ in an ecosystem.

• ______________ ______________ - each step in a food chain. • Each consumer depends on the trophic level ______________ ______________

for energy. Energy Pyramid

• Only part of the energy that is found in a trophic level is passed on to the next. • Why? • The organisms use the energy to carry out the life processes. • Only about ______________% of the energy is passed on to the next trophic

level. Biomass Pyramid

• The total amount of living tissue within a given trophic level is called ______________.

• Biomass is expressed in terms of grams of ______________ ______________ per unit ______________.

• The biomass pyramid expresses the amount of ______________ ______________ available for each trophic level in an ecosystem.

Pyramid of Numbers • This pyramid is based on the ______________ of ______________ found in the

ecosystem. • Most of the time, the shape of the pyramid is the ______________ as the biomass

and energy pyramids.

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Flow of Energy

Consumers (Heterotrophs)

Respiration (O2 + Glucose --> CO2 +H2O + Energy)

(ATP)

Herbivore Carnivore Omnivore Detritivore Decomposer

Plants Animals Both Remains Breaks Down Material

• However, sometimes the shape changes. An example would be a forest ecosystem.

3–3 Cycles of Matter Recycling in the Biosphere

• Unlike the one-way flow of energy, matter is recycled ______________ and ______________ ecosystems.

• Matter is passed from one organism to another and from one part of the biosphere to another through ______________ ______________.

• Matter can cycle through the biosphere because biological systems do not use up matter, they ______________ it.

The Water Cycle • All living things require ______________ to survive as it moves through the

ocean, atmosphere and land. • Water enters the atmosphere through the processes of ______________ and

______________ and becomes vapor. • As the vapor cools, it ______________ to form tiny droplets. • When the droplets get large enough, they fall back to Earth in the form of

______________. • When it reaches the surface of the Earth, it runs off back to the river and streams

or it enters the ground water supply.

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Pyramid of Numbers Shows the relative number of individual organisms at each trophic level.

Biomass Pyramid Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid.

Energy Pyramid Shows the relative amount of energy available at each trophic level. Organisms use about 10 percent of this energy for life processes. The rest is lost as heat.

Section 3-2

Ecological Pyramids

Nutrient Cycles

• The food you eat provides energy and chemicals that keep you alive. All the chemical substances that an organism needs to sustain life are its ______________.

• Every living organism needs nutrients to build tissues and carry out essential life functions. Like water, nutrients are passed between organisms and the environment through ______________ ______________.

• There are three nutrient cycles: 1. The ______________ Cycle 2. The ______________ Cycle 3. The ______________ Cycle

The Carbon Cycle • ______________ is a key ingredient of ______________ ______________. It is

an important component of animal ______________ and is found in several kinds of ______________.

• Carbon combined with oxygen forms ______________ ______________ which is found in the atmosphere.

• The four main processes that moves carbon through the biosphere: 1. Biological processes, such as ______________, ______________, and

______________, take up and release ______________ and ______________. 2. ______________ processes, such as erosion and volcanic activity,

______________ carbon dioxide to the atmosphere and ocean. 3. The ______________ and ______________ of dead organisms and their

conversion under pressure into fossil fuels, store carbon underground. 4. Human activities, such as mining, burning of forests and fossil fuels, release

______________ ______________ into the atmosphere.

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Section 3-3

The Water Cycle

The Nitrogen Cycle

• Many forms of ______________ occur naturally in the biosphere. • Nitrogen Gas makes up ______________ % of the atmosphere. • Ammonia, nitrates and nitrites are found in waste products

• Humans add nitrogen by adding ______________ to soil. • Bacteria can convert nitrogen gas into ammonia through a process called

______________ ______________. • Other bacteria change ammonia into nitrates or nitrites which are then absorbed

by producers to make ______________. • When organisms die, ______________ return nitrogen to the soil as ammonia. • Other bacteria convert ammonia into nitrogen gas through ______________.

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CO2 in Atmosphere

CO2 in Ocean

Section 3-3

Figure 3-13 The Carbon Cycle

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N2 in Atmosphere

NH3

NO3-

and NO2-

Section 3-3

Figure 3-14 The Nitrogen Cycle

The Phosphorus Cycle • ______________ is essential to living organisms because it forms part of

important life-sustaining molecules such as DNA and RNA. • Unlike carbon, nitrogen and water, phosphorus does ______________ enter into

the atmosphere. Nutrient Limitations

• Ecologists are interested in the rate in which organic matter is produced in an ecosystem. This is called ______________ ______________.

• One factor that controls the amount of growth in that ecosystem is the amount of available ______________.

• When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a ______________ ______________.

• ______________ is the limiting nutrient in sea water. • ______________ is the limiting nutrient in lake, rivers, and streams. • When an aquatic ecosystem receives a large input of a limiting nutrient, an

______________ ______________ results.