Bio - 8.1, 8.2, 8.3, 8.4

Question 1

xylem - transport structure

Answer 1

• leaf = outside
• stem & root = inside

Question 2

xylem

Answer 2

• made of many dead cells
• has thick walls stiffened with lignin (support)
• hollow lumen
• one way flow
• transports water & minerals

Question 3

phloem

Answer 3

• made of living cells
• no lignin
• has end walls with sieve plates
• two way flow
• transports surcose & a.a

Question 4

transpiration

Answer 4

• process by which moisture is carried through plants from roots to the stomata (where it changes to vapor and is released to the atmosphere)
• basically EVAPORATION of water from plant leaves

Question 5

5 factors that affect transpiration

Answer 5

1. wind speed
   - INCREASES = INCREASES transpiration rate
2. humidity
   - INCREASES = DECREASES transpiration rate
3. light intensity
   - INCREASES = INCREASES transpiration rate
4. temperature
   - INCREASES = INCREASES transpiration rate
5. water supply
   - DECREASES = DECREASES transpiration rate

Question 6

transpiration process / stream

Answer 6

parts : root => stem => leaf
process : water goes up => evaporates from leaves => pulls more water up
*high to low con

Question 7

capillary action

Answer 7

• how water moves UP through narrow tubes (like xylem) without needing a plant

Question 8

cohesion - capillary action

Answer 8

• water molecules stick to each other
• water chain
• after water is evaporated it needs to be replaced

Question 9

adhesion - capillary action

Answer 9

• sticks to walls
• prevents from falling back down

Question 10

basic process of transpiration

Answer 10

roots (osmosis into root hairs) => xylem (cohesion & adhesion) => leaf (evaporation from stomata)

Question 11

how have plants adapted

Answer 11

• root hair cells = high SA
• hollow xylem = easy pathway for water flow
• many air spaces = increases rate of evaporation
• stomata = opens to allow transpiration

Question 12

measuring tool for transpiration ?

Answer 12

potometer

Question 13

translocation - definition

Answer 13

• movement of organic solutes (esp sucrose and amino acids)
• via phloem
• source to sink

Question 14

phloem - translocation

Answer 14

• sucrose & amino acids
• source = leaf
• sink = roots / flowers / fruit

Question 15

source vs sink

Answer 15

• source (produces) = where sucrose is made (leaf)
• sink (receives) = where sucrose is stored / used (roots)

Question 16

tropism - definition

Answer 16

growth in response to a stimulus

Question 17

positive tropism - definition

Answer 17

towards the stimulus

Question 18

negative tropism - definition

Answer 18

away from stimulus

Question 19

phototropism - definition

Answer 19

growth in direction of light

Question 20

geotropism - definition

Answer 20

growth in direction of gravity

Question 21

hydrotropism - definition

Answer 21

growth in direction of water

Question 22

auxin - definition

Answer 22

a plant hormone that controls growth by promoting cell elongation

Question 23

auxin

Answer 23

• made of tips of shoots and roots
• can diffuse to other parts of shoots and roots
• change the rate of elongation in plant cells
  *cells in shoot elongate more
  *cells in roots inhibit elongation

Question 24

roots and flowers changing substances

Answer 24

roots : sucrose => starch (to store)
flowers : sucrose => fructose (to attract animals)

Question 25

translocation during harsh conditions

Answer 25

- plants do not photosynthesize during super hot / cold weather - sinks will become sources => convert back to sucrose => translocate to other parts of the plant (e.g) roots convert starch to sucrose