Chapter 36: Plant physiology

Question 1

adaptations for acquiring nutrients

Answer 1

1. favored taller plants and efficient transport
2. xylem and phloem
3. phyllotaxy

Question 2

phyllotaxy

Answer 2

arrangement of leaves; alternate, opposite, whorled

Question 3

advantages to living on land

Answer 3

1. more CO2 in air than in water
2. more sunlight
3. can grow larger

Question 4

disadvantages to living on land

Answer 4

1. water escapes when CO2 enters
2. higher temps and higher exposre to UV
3. need specialized tissues for resource acquisition

Question 5

mycorrhizae

Answer 5

fungi associations that increase root surface area

Question 6

movement of water and minerals

Answer 6

pulled up by negative pressure

Question 7

movement of sugars

Answer 7

pushed by positive pressure (both directions)

Question 8

solution

Answer 8

solute+solvent

Question 9

osmosis

Answer 9

water moves freely across cell membranes

Question 10

diffusion

Answer 10

solutes move down their concentration and electrochemical gradients

Question 11

transport proteins

Answer 11

facilitate movement of charged solutes through a lipid membran

Question 12

passive transport

Answer 12

solutes move down concentration or voltage gradient through a transport protein channel; does not require energy

Question 13

active transport

Answer 13

‘pumping’ a solute against its concentration gradient

Question 14

proton pump

Answer 14

uses ATP to create proton (H+) gradient across a membrane

Question 15

membrane potential

Answer 15

energy stored in H+ gradient and voltage difference

Question 16

use of membrane potential to move solutes against gradient

Answer 16

positive ions are driven to negatively charged side; cotransport of negative ions and neutral atoms

Question 17

cation exchange

Answer 17

Use H+ gradient to loosen positive ions from the negatively charged soil

Question 18

water potential

Answer 18

determines the movement of water by osmosis; solute potential + pressure potential

Question 19

solute potential

Answer 19

determined by concentration inside and outside of the cell

Question 20

pressure potential

Answer 20

provided by cell wall

Question 21

flaccid cell

Answer 21

water moves out of the cell

Question 22

plasmolysis

Answer 22

cytoplasm shrinks from cell wall

Question 23

turgid cell

Answer 23

turgor pressure pushes back against expansion of protoplasm

Question 24

aquaporins

Answer 24

transport proteins for water; quicker/ more efficient

Question 25

apoplast route

Answer 25

transport in connected spaces outside living cells; xylem

Question 26

symplast route

Answer 26

transport in connected spaces inside of cells (cells connected by plasmodesmata); sieve tube phloem

Question 27

transmembrane route

Answer 27

transport crossing cell membrane

Question 28

long distance transport

Answer 28

movement of large amounts of solutes and water by diffusion, active transport, and bulk flow; movement of fluid by pressure

Question 29

soil solution

Answer 29

water + dissolved ions

Question 30

endodermis

Answer 30

innermost layer of tissue in plants; barrier for soil solution to reach vascular tissue

Question 31

casparian strip

Answer 31

barrier for selective nutrient uptake in plants

Question 32

transpiration

Answer 32

powers xylem sap transport; pulls sap upward as water is evaporated out

Question 33

root pressue

Answer 33

pushes xylem sap upward (more difficult in tall plants)

Question 34

guttation

Answer 34

water is secreted from the tips of the leaves of small plants

Question 35

positive pressure

Answer 35

push by adding

Question 36

negative pressure

Answer 36

pull by removing

Question 37

stomata

Answer 37

opening in leaf epidermis that lets CO2 in and H2O out

Question 38

guard cells

Answer 38

open and close stomata; use K+ to change turgor

Question 39

xerophytes

Answer 39

plants adapted to dry environments

Question 40

translocation

Answer 40

movement of photosynthetic products in phloem sap

Question 41

bulk flow of phloem sap

Answer 41

sugar moves from higher concentration and pressure sugar sources to lower concentration and pressure sugar sinks

Question 42

cotransport (phloem sap)

Answer 42

sucrose and H+ cotransport enable sucrose to accumulate in the phloem