NOTES & NCERT

Question 1

types of transport in short distance transport

Answer 1

diffusion
facilitated diffusion
active transport

Question 2

long distance transport is called

Answer 2

translocation

Question 3

translocation takes place through

Answer 3

vascular system - xylem and phloem

Question 4

classify water, food, minerals and plant hormones on the basis of dxn and as organic/inorganic

Answer 4

water - inorganic, unidirectional
food - organic, bidirectional
minerals - organic & inorganic, some uni some bi
plant hormones - unidirectional

Question 5

diffusion
dxn? concentration and diffusion pressure?
enegy?
protien? related aspects?

Answer 5

high to low concentration & high DP to low DP

no energy

no protien - no transport saturation, not specific, not sensitive to inhibitors

Question 6

why is diffusion very important to plants

Answer 6

diffusion is the only means of gaseous movement within the plant body

Question 7

factors affecting diffusion

Answer 7

concentration gradient
permeability of membrane
temprature & pressure

Question 8

facilitated diffusion
process?
dxn?
energy?
protein? related aspects?

Answer 8

hydrophilic molecules are transported across the membrane through carrier proteins

high to low concentration

no energy

protein required - ✓transport saturation
✓specific and ✓sensitive to inhibitors

Question 9

transport saturation

Answer 9

transport rate reaches max when all the protein transporters are being used

Question 10

in facilitated diffusion, proteins form ___ in the membrane for molecules to pass through

Answer 10

channels

Question 11

porins
location

Answer 11

huge protein pores - allow small (protein sized) molecules to pass

outer membranes of plastids, mitochondria and some bacteria

Question 12

water channels

Answer 12

made of 8 different types of aquaporins

Question 13

uniport
symport
antiport

Answer 13

molecules move across the membrane independent of other molecules

two molecules cross the membrane in same dxn

two molecules cross the membrane in different dxn

Question 14

active transport
dxn?
energy?
protein? related aspects?

Answer 14

lower to higher concentration

energy required

proteins required - ✓transport saturation ✓specific ✓sensitive to inhibitors

Question 15

whats are pumps in active transport

Answer 15

proteins that use energy to carry substances across the cell membrane - uphill

Question 16

active transport is carried out by ___ proteins

Answer 16

membrane proteins

Question 17

___ and ___ types of transport are under hormone regulation

Answer 17

facilitated diffusion and active transport

Question 18

imbibition?
eg?
water movement is along?

Answer 18

special type of diffusion where water is absorbed by solids or colloids causing them to enormously increase in volume

absorption of water by seeds or dry wood

water movement is along concentration gradient

Question 19

due to imbibition pressure only

Answer 19

seeds are able to emerge out of the soil

Question 20

bulk or mass flow

Answer 20

the movement of substances in bulk from one point to another due to pressure difference btw the two points

Question 21

bulk flow can be achieved through ___ or ___

Answer 21

+ve hydrostatic pressure gradient
-ve hydrostatic pressure gradient

Question 22

materials translocated through xylem and phloem

Answer 22

xylem - water, mineral salts, organic N, hormones from roots to areal parts of the plants

phloem - organic and inorganic solutes mainly from leaves through other plant parts

Question 23

root hairs

Answer 23

slender extensions of root epidermal cells

Question 24

explain root hair to xylem water flow

Answer 24

root hair to root - diffusion along with mineral solutes

root to xylem:
⚫apoplast pathway -
⬛through intercellular spaces and cell walls
⬛most water flow takes place as cortical cells are loosely packed and so offer no resistance to water
⬛due to the presence of casparian strip (band of suberised matrix) at the endodermis wall the water is directed into the endodermis
⬛in young roots water enters directly into xylem vessels and trachieds. These are non living conduits and so are parts of the apoplast
⚫symplast pathway -
⬛system of interconnected protoplast connect through cytoplasmic strands extended through plasmodesmata
⬛aided by cytoplasmic streaming (eg: in hydrilla leaf)
in young roots water enters directly into xylem vessels and trachieds

Question 25

additional structures that help for water absorption by roots

Answer 25

mycorrhiza - symbiotic association of fungus and root system

hyphae have very large surface area that absorb mineral ions and water in much larger volume than a root can do

in turn, roots provide sugars and N containing compounds to mycorrhiza

Question 26

obligate association of plants and mycorrhiza

Answer 26

pinus seeds cannot germinate and establish without the presence of mycorrhiza