P1 2h transport in plants

Question 1

what are exchange surfaces in plants?

Answer 1

roots and root hairs

and leaves

Question 2

what are exchange surfaces in animals?

Answer 2

Alveoli and lungs

small intestines and villi

Question 3

what are transport system in plants?

Answer 3

xylem - moves water and mineral ions

phloem - moves sugars and amino acids

Question 4

what are transport systems in animals?

Answer 4

blood and circulatory system

Question 5

what is the xylem?

Answer 5

vessels that transport water and minerals from the roots to the stem and leaves

Question 6

what is the xylem made out of?

Answer 6

composed of dead cells which form hollow tubes

- strengthen by lignin

Question 7

what is the phloem?

Answer 7

vessels that transport food materials made by the plant

Question 8

what is the phloem made out of?

Answer 8

living cells and are not hollow

Question 9

what does the phloem transport?

Answer 9

amino acids and sucrose

Question 10

which way does the phloem go?

Answer 10

it can travel both ways

Question 11

which way does the xylem travel?

Answer 11

from roots to leaves

bottom to top

Question 12

where is the phloem in a diagram?

Answer 12

on the outside (on a cross section diagram)

Question 13

what are root hair cells?

Answer 13

single-celled extensions of epidermis cells in the root

Question 14

what are root hair cells function?

Answer 14

increase surface area to volume ratio, which increases rate of absorption of mineral ions

Question 15

how does water move into the root hair cell?

Answer 15

the cytoplasm has a low water potential so it moves into the root hair cell by osmosis

Question 16

how does root hair cells take in mineral ions?

Answer 16

active transport

Question 17

how does water move through the plant?

Answer 17

• water move into the root hair cells
• through the root cortex and into the xylem vessels
• then its carried up to the leaves to enter the mesophyll cells

root hair cell - root cortex cells - xylem - leaf mesophyll cells

Question 18

how do you investigate the pathway of water into and across a root?

Answer 18

by placing a plant like celery into a beaker of water with food colouring
- after a few hours cut the stem and find that certain parts of the celery is stained (only the xylem vessels)

Question 19

what is transpiration?

Answer 19

the loss of water vapour from the parts of the plant that are above ground level

Question 20

how does transpiration happen in plants?

Answer 20

• evaporation of water molecules from the surface of the mesophyll cells to air space
• diffusion of water vapour out of stomata (when there is a concentration gradient)

Question 21

What is the effect of transpiration?

Answer 21

due to transpiration the water in the xylem creates a continuous unbroken column of molecules
- it pulls the water into the xylem vessels

Question 22

what happens if that rate of transpiration increases?

Answer 22

if rate of transpiration from the leaves increase, water molecules are pulled up the xylem quicker

Question 23

what is the function of transpiration?

Answer 23

• transporting mineral ions
• providing water to keep cells turgid
• providing water to leaf cells
• keeping leaves cool

Question 24

what are the factors effecting transpiration?

Answer 24

air movement
humidity
light intensity
temperature

Question 25

how does air movement effect transpiration?

Answer 25

good airflow removes water vapour from air, setting up a concentration gradient

Question 26

how does humidity effect transpiration?

Answer 26

when it is very humid the air has a lot of water vapour, which makes the concentration gradient weaker

Question 27

how does light intensity effect transpiration?

Answer 27

guard cells are open in high light intensity, stomata are open and water can be lost

Question 28

how does temperature effect transpiration?

Answer 28

higher temps, particles have more kinetic energy, water molecules evaporate faster