Ch 42: Ecology

Question 1

Ecosystems

Answer 1

the sum of all organisms living within its boundaries (biotic community) and all the abiotic factors with which they interact.

Question 2

Ecosystem ecology requires two processes

Answer 2

1. Energy Flow

2. Chemical Cycling

Question 3

primary producers

Answer 3

plants

Question 4

Autotrophs

Answer 4

an organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide.

Question 5

Heterotrophs

Answer 5

an organism deriving its nutritional requirements from complex organic substances.

Question 6

Primary Consumers

Answer 6

herbivores, feeding on plants

Question 7

Secondary Consumers

Answer 7

organisms that eat primary consumers for energy

Question 8

Tertiary Consumers

Answer 8

an animal that obtains its nutrition by eating primary consumers and secondary consumers

Question 9

Decomposers

Answer 9

an organism, especially a soil bacterium, fungus, or invertebrate, that decomposes organic material.

Question 10

The amount of light energy converted to chemical energy by autotrophs is an ecosystem’s primary production

Answer 10

1%

Question 11

The spending limit for the energy budget of the entire of the ecosystem=

Answer 11

all the photosynthetic production

Question 12

Gross Primary Production (GPP)

Answer 12

total primary production in an ecosystem

Question 13

Net Primary Production (NPP)

Answer 13

GPP – the energy used by the primary produces for their “autotrophic respiration” (Ra)

Question 14

NPP

Answer 14

GPP – Ra

Question 15

In aquatic systems, primary production is affected by two factors

Answer 15

Light availability

Nutrient availability (nitrogen and phosphorus)

Question 16

A eutrophic lake

Answer 16

nutrient-rich and supports a vast array of algae. ( man-made runoff)

Question 17

In terrestrial ecosystems, primary production is affected by(3)

Answer 17

Temperature

Moisture (most important annual precipitation)

Evapotranspiration – combines both factors

Question 18

Only % of the available energy at each trophic level is passed on to the one above it.

Answer 18

10

Question 19

At each level, energy is lost too

Answer 19

Heat, For movement, reproduction, and or other life processes

Question 20

because of this loss food chains are short

Answer 20

If only 10% is passed on from primary producer to primary consumers then only 1% of net primary production (10% of 10%) is available to the secondary consumer

Question 21

Ecological pyramids

Answer 21

diagrams that give insight into food chains, biomass, energy, and pyramid numbers

Question 22

Restoration Ecology

Answer 22

The process of returning a degraded ecosystem to a more natural state

Question 23

Bioremediation

Answer 23

use organisms to detoxify polluted ecosystems, This has been used to restore areas degraded by mining or polluted by oil or radioactive elements

Question 24

Bioaugmentation

Answer 24

Introduction of desirable species such as nitrogen fixers to add essential nutrients.

Question 25

Biogeochemical Cycles(4 cycles)

Answer 25

1. water
2. carbon
3. nitrogen
4. phosphorus

Question 26

Water cycle

Answer 26

• Water is essential to all organisms
• Liquid water is the primary physical phase in which water is used
• The oceans contain 97% of the biosphere’s water; 2% is in glaciers and polar ice caps, and 1% is in lakes, rivers, and groundwater
• Water moves by the processes of evaporation, transpiration, condensation, precipitation, and movement through surface and groundwater

Question 27

The Carbon Cycle

Answer 27

• Carbon-based organic molecules are essential to all organisms
• Photosynthetic organisms convert CO2 to organic molecules that are used by heterotrophs
• Carbon reservoirs include fossil fuels, soils and sediments, solutes in oceans, plant and animal biomass, the atmosphere, and sedimentary rocks
• CO2 is taken up and released through photosynthesis and respiration; additionally, volcanoes and the burning of fossil fuels contribute CO2 to the atmosphere

Question 28

The Nitrogen Cycle

Answer 28

• Nitrogen is a component of amino acids, proteins, and nucleic acids
• The main reservoir of nitrogen in the atmosphere (N2), though this nitrogen must be converted to NH4+ or NO3– for uptake by plants, via nitrogen fixation by bacteria
• Organic nitrogen is decomposed to NH4+ by ammonification, and NH4+ is decomposed to NO3– by nitrification (by bacteria)

Denitrification: converts NO3–back to N2 (by bacteria)

• Nitrogen Fixation is the process by which bacteria take atmospheric N2 which is biological unavailable to most organisms and change it into a biologically available form that can be used.
• A plant called Legumes and the bacterium (Rhizobium) have a mutualistic relationship
• This is the major pathway for N to enter an ecosystem

Question 29

The Phosphorus Cycle

Answer 29

• Phosphorus is a major constituent of nucleic acids, phospholipids, and ATP
• Phosphate (PO43–) is the most important inorganic form of phosphorus
• The largest reservoirs are sedimentary rocks of marine origin, the oceans, and organisms
• Phosphate binds with soil particles, and movement is often localized

Question 30

Sere

Answer 30

Sequence of Growth

Question 31

Greenhouse effect

Answer 31

Causes Climate changes due to CO2

Question 32

Ozone Depletion

Answer 32

Be causing cancer due to pollution

Question 33

Acid Rain

Answer 33

decreases pH

Question 34

pollution

Answer 34

causes toxins to spread

Question 35

intro of diseases

Answer 35

in the name