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Question 1

Molecules

Answer 1

combinations of two or more atoms (N2, CO2, NaCI, H2O)

Question 2

Atoms held together by bonds (strongest to weakest):

Answer 2

1. Covalent bond
2. Ionic bond
3. Hydrogen bond

Question 3

Covalent bond

Answer 3

atoms share electrons (CO2)

Question 4

Ionic bond

Answer 4

atoms bound by electrical attraction (NaCI = Na+ + CI-)

Question 5

Hydrogen bond

Answer 5

“partial ionic bond” between molecules

Question 6

Describe a water compound

Answer 6

Partial charges at opposite ends of molecule

“Polar” molecule

Question 7

High heat capacity

Answer 7

measure of amount of heat energy that must be absorbed by the substance to raise the temperature 1 degree C

Question 8

Concentrations of H+ (protons) and OH- (electrons) determine pH in an ________ solution.

Answer 8

aqueous

Question 9

The solution is acidic if

Answer 9

H+ (protons) concentration greater than OH- (electrons)

Question 10

The solution is basic if

Answer 10

OH- (electrons) concentration is greater than H+ (protons)

Question 11

T or F: only an acidic solution can be lethal.

Answer 11

F: Both an acidic and basic solution can be lethal

Question 12

What are examples of high/basic pH?

Answer 12

NaOH (sodium hydroxide), ammonia, seawater

Question 13

What are examples of low/acidic pH?

Answer 13

acid rain, stomach acid, lemon juice, car battery acid

Question 14

What are examples of neutral pH?

Answer 14

pure water

Question 15

What elements are important for soil health and plant growth?

Answer 15

calcium, phosphorus, potassium, sulfur, nitrogen, magnesium

Question 16

What are the effects of a basic soil?

Answer 16

nutrients (e.g., P, Mg) not soluble (unavailable to plants)

Question 17

Dark leaves indicates _________ limitation/deficiency

Answer 17

phosphorus

Question 18

What are the effects of an acidic soil?

Answer 18

toxic metal ions (e.g., Al) more available/soluble

Question 19

As pH drops/Al availability increases, plants

Answer 19

grow slower

Question 20

Atoms

Answer 20

elemental units (“building blocks of matter”)

Question 21

Isotopes

Answer 21

Same number of protons, but different numbers of neutrons

Question 22

What are the two isotopes of hydrogen?

Answer 22

1. Deuterium
2. Tritium

Question 23

Deuterium

Answer 23

stable isotope (not radioactive; does not disappear)

Question 24

Tritium

Answer 24

radioisotope (radioactive, spontaneous decay occurs)

Question 25

Mass = ______ + ________

Answer 25

protons; neutrons

Question 26

What are the stable isotopes of carbon?

Answer 26

12C, 13C

Question 27

What are the stable isotopes of nitrogen?

Answer 27

14N, 15N

Question 28

Which carbon isotope is the atmosphere mostly made up of?

Answer 28

12C

Question 29

Which carbon isotope does grass and shrubs discriminate against?

Answer 29

13C

Question 30

T or F: Shrubs discriminates more strongly against 13C than grass

Answer 30

T

Question 31

Grass and shrubs use the CO2 with the preferential isotope, which is

Answer 31

12C

Question 32

Describe the salmon life cycle

Answer 32

Salmon eggs hatch in a freshwater stream Return back to the stream they were born in Female lays eggs; male fertilizes eggs Salmon die and rot

Question 33

What are the four different independent developments of agriculture?

Answer 33

China: rice Fertile crescent: wheat Central America: potatoes Mesoamerica: Corn, squash

Question 34

What are the functions of soil?

Answer 34

Regulates water cycle (controls flow of rain, snowmelt) Productivity Filters pollutants (sequester or detoxify) Nutrient cycling - Organic → inorganic

Question 35

Autotrophic plants

Answer 35

CO2 + H2O → carbohydrate CO2 + H2O + NO3 + PO4 → protein

Question 36

Heterotrophic fungi, bacteria

Answer 36

Carbohydrate → CO2 + H2O Protein → CO2 + H2O + NO3 + PO4

Question 37

Soil = mix of ____ + ______

Answer 37

organic; inorganic

Question 38

Rhizosphere

Answer 38

interface between plant roots and soil

Question 39

Rhizobium bacteria are able to break down strong ______ bonds

Answer 39

triple

Question 40

Nitrogen-fixing bacteria conversion

Answer 40

Convert N2 (gas) → NH4 (ammonium) Plants → N (organic) Soil decomposers: N (organic) → NH4 (ammonium) → N2 (gas)

Question 41

Where are mycorrhizal fungi located?

Answer 41

partly inside and outside the plant root

Question 42

Describe the relationship between mycorrhizal fungi and plants

Answer 42

Plant root gives some carbohydrate to fungi Fungi take in water and nutrients from soil environment and feed it to plant

Question 43

The relationship between mycorrhizal fungi and plants is called a

Answer 43

mutualistic symbiosis

Question 44

How are non-native earthworms a threat to soil?

Answer 44

Reduce soil biodiversity, productivity

Question 45

What percent of all freshwater use is for crop irrigation?

Answer 45

70%

Question 46

Why is over-irrigation a problem?

Answer 46

Over-irrigation → waterlog plant roots → poor growth, death Soil becomes soggy Roots need oxygen Too much water Oxygen diffuses much slower Plants are not getting enough oxygen

Question 47

Salinization

Answer 47

buildup of salts in surface soil layers

Question 48

Describe the process of salinization

Answer 48

Sfc evaporation removes water, leaves salts: - Water comes up to surface and evaporates - Salts in the water do not come up to surface and are left behind

Question 49

What is the problem with conventional irrigation practices?

Answer 49

< half of water reaches plants Most of the water released from the rotators is evaporated

Question 50

Why is drip irrigation a better irrigation practice?

Answer 50

Conserves water, saves money and reduces salinization Water drips out slowly (reduces chance of evaporation)

Question 51

As a result of over-fertilization, rain washes off _____ and _____ from lawn into water

Answer 51

nitrogen; phosphorus

Question 53

Give examples of how isotopes can be used to better understand environmental process?

Answer 53

[Marine 15N/14N] ≠ [terrestrial 15N/14N] • Marine food —> salmon body —> death, decay —> terrestrial • Terrestrial invertebrate animals near stream: up to 70% of N in body • Salmon acts as fertilizers for animals that lice on land far from the ocean • Salmon collect N from the ocean • Salmon deposit N after death