02.11 - plants / photosynthesis - hard

Question 1

Meristem

Answer 1

Rapidly dividing undifferentiated cells found in the growing tips and roots.
Differentiate to form other types of cells

Question 2

Xylem (brief)

Answer 2

Non-living transport tissue

which carries water + dissolved minerals from root to leaves

Question 3

Phloem (brief)

Answer 3

Living transport tissue

Carries sugars + amino acids from leaves to rest of plant

Question 4

What’s translocation

Answer 4

Movement of dissolved sugars from source to sink through the phloem to be stored or used immediately or stored

Question 5

Phloem structure

Answer 5

Living cells in a tube shape
Contain little cellulose but no nucleus / organelles
Kept alive by companion cells

Question 6

Sieve plates

Answer 6

End of each cell contains a sieve plate which has pores to allow dissolved sugars to pass from cell to cell

Question 7

Transpiration

Answer 7

The evaporation of water when the stoma are open

Transpiration is the evaporation of water from the surface of a plant, such as from its leaves.

Question 8

Xylem structure

Answer 8

hollow tubes strengthened by dead lignin

Adapted for water transport as the lignin dead so it won’t absorb the H2O

Question 9

Why’s water important for the plant

Answer 9

Reactant photosynthesis

keeps cells turgid = without H2O plant droops

Question 10

Why are minerals important for plants

Answer 10

Magnesium = chlorophyll production 
Nitrates = protein growth + amino acid production 
Potassium = general chemical reactions

Question 11

Uses of glucose from photosynthesis (5)

Answer 11

1. Respiration
2. Convert into insoluble starch (storage)
3. Convert to fat/oils (storage)
4. Cellulose production (strengthens cell wall)
5. Amino acid production

Question 12

Effect of temperature on transpiration

Answer 12

As temp increases kinetic energy of water molecules increases - faster rate of diffusion and evaporation
Graph = increase then straight line

Question 13

Effect of humidity on transpiration

Answer 13

Arid / dry = big difference in water concentration between leaf and environment so transpiration happens quickly
Moist = little difference in water concentration between leaf and environment so transpiration happens slowly
Graph = negative (goes down in straight line) staring at dry —> moist

Question 14

Effect of air movement on transpiration

Answer 14

Wind reduces water vapour around the stone (diffusion occurs faster) maintains the concentration gradient.
Graph = goes up (starting at still —> windy)

Question 15

Effect of light intensity on transpiration

Answer 15

Increases the number of open stoma so transpiration rate increases
Graph = goes up as light intensity increases

Question 16

Limiting factor for photosynthesis (light intensity)

Answer 16

Increasing the light intensity increases the photosynthesis rates to a certain point until it’s no longer the limiting factor

Question 17

Limiting factor for photosynthesis ( co2 concentration)

Answer 17

The atmosphere only contains 0.04% co2 so it’s often the limiting factor. As the co2 conc increases the rate of photosynthesis increases until its not the limiting factor anymore

Question 18

Limiting factor for photosynthesis (temperature)

Answer 18

Temperature effects enzymes and photosynthesis is an enzyme controlled reaction.
As temperature increases the rate of photosynthesis increases up until a certain point, once it’s reached it’s optimum temperature that’s when photosynthesis rates are the highest. Anything after the optimum temp is when the enzymes begin to denature so the photosynthesis rates decrease rapidly

Question 19

Epidermal tissue

Answer 19

Thin + transparent to allow more light to reach palisade cells
Waxy layer - water loss + infection prevention

Question 20

Palisade mesophyll

Answer 20

Long + thin (rectangles) to fit more in a certain space

Contains lots of chloroplasts = more photosynthesis/ light absorption

Question 21

Spongy mesophyll

Answer 21

Has air spaces so gases can diffuse rapidly

Has chloroplasts so that it can absorb any light that the palisade cells missed

Question 22

Guard cells

Answer 22

Guard cells become turgid and swell when the water concentration in the leaf is high as the water moved into the guard cells via osmosis so the stoma open allowing H2O gas to diffuse out and CO2 to diffuse in . When the water concentration is low the water moves out of the guard cells causing them to become flaccid so the stoma shut so water vapour is unable to leave the leaf.

Question 23

Flower

Answer 23

Reproductive organ

Question 24

Leaf

Answer 24

Photosynthesis

Question 25

Roots

Answer 25

Anchor plant

Absorbs minerals + water via active transport and osmosis

Question 26

Stem

Answer 26

Support

Substance movement “

Question 27

Transpiration stream meaning

Answer 27

The movement of water and mineral ions through a plant (root to leaves) via the xylem