Lecture 9 - Energy Balance in Plants

Question 1

epidermis

Answer 1

production of root hairs, which project into the soil increasing surface for water and nutrient uptake

Question 2

what are 2 of the pathways that water moves from the soil to xylem

Answer 2

symplast and apoplast

Question 3

suberin

Answer 3

cell wall-associated biopolymer found in the endodermis

Question 4

water moves from areas of ____ water potential to areas of ______ water potential

Answer 4

high, low

Question 5

what location can you expect the highest water potential in plant roots

Answer 5

root epidermis (might be wrong)

Question 6

what is hydropassive response

Answer 6

close stomata

Question 7

a plant in drought generates _____ solute potential to cause more water to move into the plant

Answer 7

low

Question 8

the solute potential is _____ when solutes are added to an aqueous system

Answer 8

reduced

Question 9

2 main drought mechanisms that affect turgor pressure

Answer 9

elastic adjustment
osmosis adjustment

Question 10

modes of energy exchange

Answer 10

conduction
convection
latent heat transfer
radiative exchange

Question 11

conduction

Answer 11

individual molecules transfer kinetic energy from one to another but they do not move far in the process

Question 12

convection

Answer 12

individual molecules gain kinetic energy from one region and themselves transfer it to another region

Question 13

latent heat transfer

Answer 13

latent heat of vaporization (amount of energy needed to change from liquid to vapor)

Question 14

what other mode of energy exchange does latent heat transfer use

Answer 14

kinetic energy to allow molecules to escape H bonding at the air-water-interface and vaporize

Question 15

radiative exchange

Answer 15

all matter acts as a near-perfect black body that absorbs and emits all radiant energy
Basically the amount of energy emitted/reradiated from a body

Question 16

high temperatures have ____ wavelengths and ____ emissivity energy

Answer 16

short, strong

Question 17

low temperatures have _____ wavelengths and ______ emissivity energy

Answer 17

long, weak

Question 18

where does the leaf get its energy input

Answer 18

radiant energy from the sun

Question 19

different kinds of energy inputs and where they come from

Answer 19

short wavelengths for sun
long wavelengths from soil and air

Question 20

conduction in leaves

Answer 20

direct transfer of heat energy from leaf to surrounding atmosphere: boundary layer

Question 21

transpiration

Answer 21

evaporation of water mainly through the stomata of leaves

Question 22

convection in leaves

Answer 22

transport of energy by volume of air/wind

Question 23

different ______ can affect conduction and convection in leaves

Answer 23

leaf shapes

Question 24

how can drought conditions affect photosynthesis

Answer 24

rates of photosynthesis can drastically decrease

Question 25

what do spines function as in plants

Answer 25

reflectors and reradiators to reflect sun to reduce heat

Question 26

if plants are under drought stress conditions, a new _______ equilibrium will be established at each leaf surface

Answer 26

thermal