chapter 25: flowering plants nutrition and transport

Question 1

Nitrogen is an essential nutrient for optimal plant growth because it is used to build
a.
Protein

b.
DNA

c.
Mitochondria

d.
All of these are correct

e.
Nucleic acids

Answer 1

d.
All of these are correct

Question 2

Which of the following particles are retained by clay soil and exchanged for hydrogen ions when plants take them up?
a.
Calcium & potassium

b.
Iron & boron

c.
Calcium & copper

d.
Calcium & ammonium

e.
Sodium & sulphur

Answer 2

a.
Calcium & potassium

Question 3

What is the main factor that will determine whether or not water can enter the root cells?
a.
Volume of water available

b.
A lower osmotic pressure in the root tissues than the soil solution

c.
Type of plant cells that are exposed to the water

d.
A higher osmotic pressure in the root tissues than the soil solution

Answer 3

b.
A lower osmotic pressure in the root tissues than the soil solution

Question 4

Which of the following is not involved in mineral uptake by plant roots?
a.
Expending energy in uptake/active transport

b.
Root hairs that increase surface area

c.
Root nodules that fix atmospheric nitrogen

d.
Cuticles that protect surfaces

Answer 4

d.
Cuticles that protect surfaces

Question 5

In the pressure-flow model of phloem transport, the sink is normally
a.
Lenticels

b.
The roots

c.
The stem

d.
Xylem

Answer 5

b.
The roots

Question 6

where does carbon come from

Answer 6

carbon dioxide

Question 7

where do hydrogen and oxygen come from

Answer 7

water

Question 8

what is a mineral

Answer 8

naturally occurring inorganic substance containing 2+ elements

Question 9

what is nitrogen

Answer 9

builds nucleic acids, proteins, mitochondria, DNA

Question 10

what are the 3 qualifications for essential nutrients

Answer 10

1. Identifiable role
2. No other nutrient can substitute it and fulfill the same role
3. Deficiency of this nutrient disrupts plant function and metabolism

Question 11

what is soil

Answer 11

Mixture of mineral particles, decaying organic matter, living organisms, air, & water
-typically a mix of sand, silt, and clay particles

Question 12

what are the 3 ways soil is formed

Answer 12

1. Mechanical weathering of bedrock
2. Chemical weathering of rock
3. Decomposition of organic matter

Question 13

what is humus

Answer 13

-decomposing organic matter
-Loose, crumbly texture
-Allows water to soak in w/out removing -air pockets
-Decreases runoff
-Aerate soil
-Nutritious

Question 14

what are the three soil particles

Answer 14

sand, silt, and clay

Question 15

what is the ideal loam soil

Answer 15

Ideal loam soil: combines aeration provided by sand with mineral- & water-retention of silt and clay

Question 16

how does soil relate to living organisms

Answer 16

-Small plants help form soil
-Wide variety of animals dwell in soil
-Ingest fine soil particles& deposit them surface
-Aerating soil
-Decomposition of organic remains
-Bacteria make nitrogen available

Question 17

what are soil horizons

Answer 17

major layer of soil visible in a vertical profile

Question 18

what is a soil profile

Answer 18

vertical section from the ground surface to the unaltered rocks below
-soil profile varies according to their particular ecosystem

Question 19

what are human causes of soil erosion

Answer 19

1. Deforestation
2. Desertization
   -not watering soil effectively, becomes too dry, nutrients become inaccessible
3. Poor farming practices
   -50% + of world’s farmland is terribly degraded

Question 20

water and minerals use the same pathways, but when does water enter roots?

Answer 20

when osmotic pressure in roots is lower than soil

Question 21

what are rhizobium bacteria

Answer 21

-Live in root nodules
-Bacteria “fix” atmospheric nitrogen to ammonium
-Host plant provides bacteria with food & shelter

Question 22

what do bacteria (rhizobium) do to atmospheric nitrogen to ammonium

Answer 22

fix or transform

Question 23

what are mycorrhizae

Answer 23

-Association between fungi & plant roots
-Increases the surface area for water and mineral uptake and break down organic matter
-Root provides sugars & amino acids

Question 24

what are xylem

Answer 24

Transports WATER & minerals roots to leaves
1. Tracheid
2. Vessel elements

Question 25

what is a tracheid

Answer 25

tapered at both ends; ends overlap with adjacent tracheids; pits allow water to pass from one to another

Question 26

what are vessel elements

Answer 26

long & tubular; perforation plates at each end; placed end to end to form a hollow pipeline

Question 27

what is phloem

Answer 27

Transports organic materials (SUGAR) to ALL parts of plant
1. sieve-tube members
2. companion cells

Question 28

what are sieve-tube members

Answer 28

conducting cells. End walls called sieve plates & have many pores; strand of cytoplasm go from one sieve-tube member to another through pores; lack nuclei

Question 29

what are companion cells

Answer 29

have nuclei; provide proteins & support to sieve-tube members

Question 30

what is water potential

Answer 30

-potential energy of water; a measure of the capability to release or take up water relative to another substance
-Water chemical properties important in movement
-Water large part of both xylem & phloem sap
-leads to root pressure

Question 31

where is the highest water potential

Answer 31

The roots, that is where it is getting absorbed

Question 32

what are characteristics of water transport

Answer 32

Mineral accumulate high concentrations in root
Solute concentration results water continuously moving into root

Question 33

what is root pressure

Answer 33

Osmotic pressure caused by active movement of minerals into root cells; elevates water in xylem for a short distance

Question 34

what is guttation

Answer 34

liberation of water droplets from edges & tips of leaves, resulting from root pressure
-buildup of water potential

Question 35

what is transpiration and why does it occur

Answer 35

-tension caused by evaporation; explains how water can resist gravity & travel upward
-Waters ability to stay linked in a chain is called cohesion
-Waters ability to stick to inside of xylem vessel is called adhesion
*All water entering creates root pressure, not enough

Question 36

what is the cohesion-tension model of xylem transport

Answer 36

-Transpiration
-Tension
-Pulls water column: water molecules joined together in xylem from -leaves to roots
-Cohesion
-Enters xylem

Question 37

what is the role of phloem in organic nutrient transport

Answer 37

Found external to xylem
Not defined by gravity; travel in any direction
Source: location of sugar production.
-typically in leaf
Sink: location from which sugar is constantly being removed
-active sites of a plant, where growth is happening, need supply
of ATP
Sugar will flow from source to the sink

Question 38

how does sugar transportation work

Answer 38

-establish concentration gradient
-phloem sends H+
-H+ and sucrose cotransport
-Transported from cells in leaves mesophyll into sieve tubes
-Loading is sugar dependent on electrochemical gradient
-Proton pump

Question 39

how does the pressure-flow model of phloem transport work

Answer 39

Sugar produced by leaves
Transported into sieve tubes
Water by osmosis
Positive pressure to sink
Stored
Cellular respiration
Water exits by osmosis back to xylem