Plants-Transport in vascular tissue

Question 1

Vascular tissue

Answer 1

consists of xylem and phloem (both made of cells that form long, continuous tubes):

1. Xylem: dead cells at maturity; used to transport water and minerals; always up
2. Phloem: living cells at maturity; used to transport sugars dissolved in water up OR down

Question 2

Xylem transport

Answer 2

1. Water and minerals move into the xylem at the root:
   - H2O by OSMOSIS – moves from high conc. in soil to low conc. in root
2. Minerals by ACTIVE TRANSPORT – use energy to move from lower conc. in the soil to higher conc. in the root

Question 3

3 processes to move water up to the stem and leaves

Answer 3

ROOT PRESSURE – pumping nutrients into root causes H2O molecules to move into the root creating a region of high pressure, forces xylem sap up to areas of lower pressure

CAPILLARY ACTION – attraction between H2O molecules (cohesion) and between H2O molecules and the sides of the xylem (adhesion) allows H2O molecules to “climb” up a narrow tube

TRANSPIRATION PULL – as one H2O molecule is lost through the stomata, another H2O molecule is pulled up behind it (cohesion)
-TRANSPIRATION – evaporation of water through the stomata of leaves

Question 4

What are the Outcomes of insufficient water supply in plants

Answer 4

PLANTS WILL WILT

-Due to lack of TURGUR PRESSURE (pressure that exists when vacoules are full of H2O)

Question 5

Phloem transport

Answer 5

Two areas – SOURCE (high conc. of sugars, e.g. leaf) and SINK (low conc. of sugars, e.g. root, where sugar used or stored)

Movement is always from SOURCE to SINK (TRANSLOCATION – long distance transport through phloem)

Sugar (in water) will move from area of high pressure in phloem (SOURCE) to low pressure (SINK), along pressure gradient

Question 6

What happens at the SOURCE in phloem transport?

Answer 6

At the SOURCE – sugar actively transported into phloem, water also travels into phloem (creates high pressure area in phloem – FULL of sugar water)

Question 7

What happens at the SINK in phloem transport?

Answer 7

At the SINK – sugars diffuse from the phloem to the sink cells, water also leaves the phloem (creating low pressure area in phloem)