Chapter 3

Question 0

What are the three factors that sustain earth’s life?

Explain each one.

Answer 0

The one way flow of high quality energy: comes from the sun through living things in their feeding interactions, into the environment as low quality energy - cannot be recycled
The cycling of nutrients: its essential that our fixed supply of nutrients are recycled to support life.
Gravity: allows the planet to hold onto its atmosphere and helps enable the movement and cycling of chemicals,.

Question 1

What are Earth’s 4 major components of its life-support system? Explain what each one is.

Answer 1

Atmosphere - thin layer of gases surrounding earths surface
Hydrosphere - consists of all water on or near earths surface
Geosphere - consists of earths intensely hot core, a thick mantle composed mostly of rock, and a thin outer crust
Biosphere - consists of the parts of the atmosphere, hydrosphere and grips here where life is found.

Question 2

What percent of incoming energy goes to generating winds?

Answer 2

1%

Question 3

What percent of energy do plants use to go through photosynthesis?

Answer 3

0.1%

Question 4

What usually happens to energy that reaches earth? What form?

Answer 4

It is reflected back into the space as lower quality energy in the form of longer wave length infrared radiation.

Question 5

How much energy intercepted by our earth actually reaches the surface?

Answer 5

about half

Question 6

What happens to greenhouse gases what effect do they have on our earth?

Answer 6

The infrared radiation that is leaving our earth encounters greenhouse gases which vibrates them and causes them to release radiation with even longer wavelengths. The vibrating gases have higher kinetic energy and help warm our earth. Without these, our earth would be too cold to support life.

Question 7

How can greenhouse gases be produced and how does this affect earth?

Answer 7

Burning fossil fuels and growing crops produces too much greenhouse gas which is warming the earth more and more and is projected to alter earths climate change.

Question 8

What is ecology?

Answer 8

The study of how organisms react with one another and with their nonliving environment of matter and energy.

Question 9

What are the 5 main levels that ecologists study?

Answer 9

Organisms, populations, communities, ecosystems, and biosphere

Question 10

What is the equation for photosynthesis?

Answer 10

6CO2 + 6H2O + energy –> C6H12O6 + 6H2O

Question 11

What is chemosynthesis?

Answer 11

Only used by a few producers, mostly bacterias, can convert simple inorganic compounds from their environment into more complex nutrient compounds without using sunlight.

Question 12

Consumers/heterotrophs

Answer 12

Cannot produce the nutrients they need through photosynthesis or other processes, so they feed on other organisms. Humans and all other consumers are heterotrophs.

Question 13

Decomposers

Answer 13

In the process of obtaining their own nutrients, they also release nutrients from the wastes or remains of plants and animals and then return those nutrients to the soil, water and air.

Question 14

Detritus feeders

Answer 14

Feed on wastes or dead bodies of other organism.

Question 15

Aerobic respiration

Answer 15

Producers, consumers and decomposers use the chemical energy stored in glucose to fuel their life processes. Uses oxygen to convert glucose back into carbon dioxide and water.

Question 16

Anaerobic respiration or fermentation

Answer 16

Decomposers break down glucose in the ABSENCE of OXYGEN. Also the end products are compounds such as methane gas, ethyl alcohol and acetic acid instead of carbon dioxide and water.

Question 17

Biomass

Answer 17

The dry weight of all organic matter contained in its organisms in any food chain or food web.

Question 18

GPP or gross primary productivity

Answer 18

The rate at which an ecosystem’s producers convert solar energy into chemical energy in the form of biomass. Measured in kilocalories per square meter.

Question 19

NPP or net primary productivity

Answer 19

GPP minus the rate at which they use some of this stored energy through cellular respiration.

Question 20

Explain the steps of the Phosphorus cycle.

Answer 20

Phosphorus runs off into ocean and gets deposited in the bottom. Phosphorus from the mountains erodes because of rivers into lakes (or any body of water), this water is taken in by plants which is then passed on to the consumer. When the consumer dies, it decomposes back into water/land.

Question 21

What are the human impacts that cause phosphorus to be released into the environment?

Answer 21

Mining, fertilizers (inorganic runs off more easily)
Removing trees causes weathering and erosion
Detergents

Question 22

List the 5 ways that Carbon is released into the environment.

Answer 22

1. The carbon that the plants produce during photosynthesis is passed onto the consumer.
2. Combustion of firewood releases CO2 into the environment.
3. Decomposition releases carbon into soil and air
4. CO2 in the air dissolves into ocean and creates limestone deposits in the bottom.
5. Volcanoes

Question 23

What are crustacean’a shells made from?

Answer 23

They take C from the water to make CaCO3

Question 24

What is the formula for acid rain?

Answer 24

H2CO3

Question 25

What’s the largest carbon sink?

Answer 25

The ocean

Question 26

What’s the residence of carbon in atoms, soils, rocks in ocean and fossil fuels?

Answer 26

Atom 3 years
Soils 25-30 years
Rocks in ocean 1500 years
Fossil fuels millions of years

Question 27

How are fossil fuels created?

Answer 27

When a log or something gets buried in a swamp and all the moisture gets sucked out of it.

Question 28

Nitrogen fixation

Answer 28

Rhyzobium Bacteria latches onto stems of plants which also turn N2 Ito NO3.

Question 29

Assimilation

Answer 29

Plants take NO3 or NH3.

Question 30

Nitrification

Answer 30

Bacteria takes ammonia and turns it into NO2 and NO3.

Question 31

Ammonification

Answer 31

When nitrogen is turned into ammonia during decomposition

Question 32

Denitrification

Answer 32

Bacteria turns NO3 into N2 and puts it back into the environment.

Question 33

Where does nitrogen fixation take place besides plants?

Answer 33

Lighting and burning fossil fuels (which releases NOX)

Question 34

What are the 7 human changes of the nitrogen cycle?

Answer 34

1. Commercial fertilizers have doubled the amount of fixed nitrogen in the environment
2. Burning fossil fuels
3. Livestock waste
4. Mine nitrogen deposits
5. Remove it from topsoil
6. Acid rain
7. Runoff into aquatic systems
   
   • drinking water contamination
   • eutrophication = algal bloom = algae dies = decomposers = uses of oxygen and fish die

Question 35

Eutrophication

Answer 35

An ecosystems response to the addition of artificial or natural substances (nitrates and phosphates)