Chapter 37

Question 1

What elements does fertilizer often have?

Answer 1

Phosphorous, Nitrogen, Potassium

Question 2

What does phosphorous do?

Answer 2

Part of DNA/RNA, ATP, phospholipids

Question 3

What does Nitrogen do?

Answer 3

Forms DNA, proteins, chlorophyll

Question 4

What does potassium do?

Answer 4

Cofactor for enzymes used throughout cell, major roll in maintaining turgor (H2O pressure)

Question 5

Is soil made up of biotic or abiotic material?

Answer 5

It has components of both

Question 6

Why is soil erosion so bad?

Answer 6

It can take centuries to form but only years to be destroyed

Question 7

How does soil texture range?

Answer 7

Very coarse (sand)–> very fine (clay

Question 8

What is humus? Where is it found?

Answer 8

Decomposing organic material that is part of the topsoil layer

Question 9

What is topsoil? Why is it important?

Answer 9

Horizon/top layer of soil- plants depend on it

Question 10

What are the layers of soil like?

Answer 10

Broken down rock, living/dead organisms
Much less organic matter, less weathered
Broken down rock

Question 11

What are loams?

Answer 11

Most fertile topsoil, about equal amounts of sand, silt, and clay

Question 12

What is in soil solution?

Answer 12

H2O and minerals

Question 13

Where do roots absorb their nutrients?

Answer 13

Soil solution

Question 14

What organisms are found in soil?

Answer 14

Fungi, algae, protists, insects, worms, plants

Question 15

What does soil biodiversity determine for the soil?

Answer 15

pH and chemical properties

Question 16

What are some common causes of reduced soil productivity?

Answer 16

Chemical contamination, mineral deficiencies, changes in pH, changes in salinity

Question 17

What is sustainable agriculture?

Answer 17

Long-term practices that are environmentally safer

Question 18

What are the benefits of irrigatin?

Answer 18

Increased crop yield, balances salt levels

Question 19

What is fertilization?

Answer 19

The practice of recycling mineral nutrients

Question 20

What is phytoremediation?

Answer 20

Using living plants to clean soil, air and water (EG nuclear radiation)

Question 21

What are the essential comounds for plants?

Answer 21

Cellulose and starch

Question 22

How many essential nutrients are there for plants? How many of each?

Answer 22

17, 9 macro, 8 microW

Question 23

What contributes the most to plant growth and crop yields?

Answer 23

Nitrogen

Question 24

LOOK AT MUTUALISM DIAGRAM

Question 25

What is a mutualism?

Answer 25

An interaction between 2 species that benefits both

Question 26

What are some expamples of mutualisms?

Answer 26

Ants defend plant from attack, plant provides food Shrimp digs burrow where it and goby live, goby acts as lookout and shrimp is protected while goby has shelter

Question 27

What is the rhizosphere?

Answer 27

Area around roots/in soil

Question 28

Where can bacteria in rhizosphere live?

Answer 28

Free living in rhizosphere or as endophytes (in plants)

Question 29

How do bacteria benefit as endophytes?

Answer 29

Get sugars, amino acids, organic acids from plant cells

Question 30

How do plants benefit as endophytes?

Answer 30

Antibiotics, chemicals that stimulate plant growth

Question 31

What helps determine the species composition of bacterial communties?

Answer 31

Whether it's inside/outside the root and by soil type

Question 32

Where is the role of bacteria important in plant nutrition?

Answer 32

The nitrogen cycle

Question 33

Why do bacteria take up atmospheric nitrogen?

Answer 33

It isn't usable to plants

Question 34

What converts atmospheric nitrogen into a form that's usable by plants?

Answer 34

Nitrogen fixing bacteria (Produce ammonium)

Question 35

How can nitrogen already present in the soil be converted to a form usable by plants?

Answer 35

Decomposition by Ammonifying bacteria, (Produce ammonium)

Question 36

What happens to ammonium in the soil?

Answer 36

Nitrifying bacteria convert it to nitrite, then nitrate, which either gets denitrified and released into the atmosphere as N2 or the NO3 gets absorbed into plant roots