acquisition of water and the concept of water potential/plant responses to internal and external stimuli

Question 1

what is the definetion of active transport

Answer 1

movement of some materials across membranes take place using ATP - this method of transpotation is active transpotation

Question 2

due to what type of energy in molecules does diffusion take place ?

Answer 2

thermal energy

Question 3

what is the definition of diffusion?

Answer 3

• in the absence of any other forces
• the movement of a substence
  -from high concentrated place to a low concentrated place
  -due to random motion
  is defined as diffusion

Question 4

true or flase
diffusion is directional

Answer 4

the motion of a particle is random but in diffusion the flow of population of molecules is directional

Question 5

diffusion takes place only through the membranes
true or false

Answer 5

diffusion takes place without membranes and also when the membrane is permiable for the certain subject

Question 6

osmosis definition

Answer 6

the diffusion of free water molecules through a selectivly permiamable membrane

Question 7

imbibition

Answer 7

the physical adsorbsion of water by hydrolic materials

Question 8

what is an example of imbibition

Answer 8

the taking up of water by cellose cell wall during seed germination

Question 9

what is the defintion of facilitated diffusion

Answer 9

the movement of water and hydrophilic solutes across the membrane passivly from high conc to low conc with the help of transport proteins that span the membrane .

Question 10

what is bulk flow ?

Answer 10

is the movement of liquid and entire solution in reponse to the pressue gradient

Question 11

what is faster , bulk flow or diffusion

Answer 11

bulk flow , this does not occur through the membranes .

bulk flows is independent of solute gradient

Question 12

another name for solute potential
solute potential is directly propotional to

Answer 12

osmotic potential
the molarity of the solution

Question 13

the water potential of pure water

Answer 13

0MP

Question 14

the pressue in the xylem?

Answer 14

less than -2MP
negetive pressue

Question 15

is the living cell under positive or negetive pressue and explain the reason

Answer 15

positive pressue due to the osmotic uptake of water

Question 16

define water potential

Answer 16

the physical property which decide the direction of the water flow governed by the solute concentration and the applied pressue

Question 17

what is known as plasmolysis ?

Answer 17

the protoplast of the cell srinks and removes from the cell wall

Question 18

what are the functions of the tugor pressue

Answer 18

support for the non woody plant
cell elongation

Question 19

what is known as photomorphogenesis?

Answer 19

the key events of the plant growth and devolopment that are tirggerd my light

Question 20

what are the most importetent colures that help in plant growth and devolopment

what proves this

Answer 20

red and blue

the action spectrum

Question 21

what are the photoreceptors involving in photomorphogenesis?

Answer 21

phytochrome - red light receptor
chyptochrome - blue light receptor

Question 22

what is the major photoreceptor that involve in seed germination ?

Answer 22

phytochorme

Question 23

what are some examples for photomorphogenesis

Answer 23

shade avoidence , flowering , light induced hypocotile elongation inhibition

Question 24

what does far red light do for seed germination ?

Answer 24

it inhibits it

Question 25

what does blue light do for photomorphogenesis

Answer 25

when the shoot is exposed to light the light induced slowing down hypocotile elongation is induced my blue light receptors

Question 26

what does the exposture to direct sunlight do regarding phyptochromes ?

Answer 26

increases the propotion of far red to red light and therfore inhibits branching and promotes branching

Question 27

what is defined as the photoperiod

Answer 27

the time period within the 24h that the plant is exposed to to light

Question 28

what function of the plant does the photoperiod control ?

Answer 28

flowering

Question 29

which phytochrome invovle in the shoot elongation ?

Answer 29

phytochromes

Question 30

how do plants detect gravity? and how do they function?in the root where are they located?

Answer 30

by statoliths

Question 31

what are statoliths?

Answer 31

in vascular plants they are plastids with dense starch grains

Question 32

explain the statolith hypothesis?

Answer 32

the statoliths in the root cap cells get accumulated to the bottom , this stimulate the accumulation of Ca2+ ions and then the growth regulators such as auxin in the lower side of the elongation zone of the root at high concentrations the elongation is inhibited by auxin in the lower side , the upper side grows more consequently the root grows downward

Question 33

what is a uniques characteristic of trees in winder enviroments ?

Answer 33

shorter and stockier trunks

Question 34

what is named as thigmomorphogenesis

Answer 34

the effect of the mechanical stess on the plant

Question 35

what is a unique structure of climbing plants

Answer 35

tendrills

Question 36

explain the thigmonastic reaction of the mimosa pudica?

Answer 36

touching the leaves result in a sudden loss of tugor in cells in the special motor organ called pulvivi.