plant vascular tissues

Question 1

func of xylem

Answer 1

transports water & dissolved minseral salts from roots to other parts of plant, provide mechanical support

Question 2

adv of long & hollow lumen (xylem)

Answer 2

reduced resistance to allow for continuous & incr rate of transport

Question 3

adv of lignified walls (xylem)

Answer 3

provides mech support when xylem vessels are bundled together to allow for continuous & incr rate of transport

Question 4

what are parenchyma cells (xylem)

Answer 4

typical plant cells which undergo specialisation to form xylem tissues

Question 5

func of phloem

Answer 5

transports manufactured food (sucrose, amino acids) from leaves to other parts of plant

Question 6

adv of sieve tubes elements which have little protoplasm & joined end to end (phloem)

Answer 6

reduced resistance to facilitate incr ease & rate of flow of subst through a continuous column

Question 7

adv of pores in sieve plates (phloem)

Answer 7

allow for rapid flow through sieve tubes –> incr rate of flow of sucrose & amino acids

Question 8

adv of numerous mitochondria in companion cells (phloem) FROM WHERE TO WHERE

Answer 8

release more energy through incr rate of cellular resp –> incr rate of AT to load sugars from mesophyll cells into sieve tube

Question 9

what is a cambium

Answer 9

tissue btw xylem & phloem, can divide & differentiate to form new xylem & phloem tissues

Question 10

func of pith in stem

Answer 10

contains regular plant cells, storage tissue

Question 11

func of epidermis

Answer 11

covers stem, protected by waxy waterproof cuticle that reduces evaporation of water from stem

Question 12

how are mineral salts absorbed into rhc when conc of ions in soil is higher than conc in rhc

Answer 12

diffusion

Question 13

how are mineral salts absorbed into rhc when conc of ions in soil is lower than conc in rhc

Answer 13

active transport

Question 14

func of rhc

Answer 14

absorb water molecules & dissolved mineral salts from surroundings into root

Question 15

adv of long narrow protrusion (rhc)

Answer 15

greater sa:v ratio –> incr rate of absorp

Question 16

adv of cell sap w lower w.p than surroundings (rhc)

Answer 16

maintain steep conc gradient –> allows h2o to continuously enter cell by osmosis down the w.p gradient

Question 17

adv of uniformly thin cell wall (rhc)

Answer 17

less dist for movement of subst via diffusion/osmosis –> incr rate of absorp

Question 18

adv of numerous mitochondria in rhc

Answer 18

release energy through cellular resp –> incr rate of AT for absorp of h2o & mineral salts

Question 19

how does water enter the rhc and into xylem vessels

Answer 19

water enters rhc through osmosis (w.p in sap lower than w.p in soil solution).

inside rhc, water enters next cell through osmosis (now rhc sap has higher w.p than next cell sap’s w.p)

process continues until water reaches xylem vessels