lab 5

Question 1

leaf lamina

Answer 1

everything branching from stem

Question 2

sessile vs petiole

Answer 2

sessile = no stalk attaching leaf to stem
petiole = attaches leaf to stem

Question 3

characteristics of true leaves

Answer 3

• complex vasculature
• leaf gap
• lateral shoot bud or axillary bud (everything distal to this bud counts as one leaf)

Question 4

leaf complexity

Answer 4

simple vs compound

Question 5

leaf arrangement

Answer 5

pinnate vs palmate

opposite vs alternate

Question 6

leaf venation

Answer 6

parallel vs netted

Question 7

leaf anatomy top to bottom

Answer 7

cuticle with stomata/guard cells
epidermis
palisade mesophyll --> light absorption 
spongy mesophyll --> gas exchange
vascular tissue

Question 8

mesomorphic plants

Answer 8

adapted to moist environments

• single layer epidermis with thin cuticle
• epidermis is thicker than hydromorphic

Question 9

hydromorphic plants

Answer 9

adapted to wet environments

• single layer epidermis
• no cuticle
• vast spongy layer for buoyancy

Question 10

xeromorphic plants

Answer 10

adapted to dry environments

-super thick epidermis and cuticle

Question 11

tricones

Answer 11

stuff in stomata that protect from water loss and predation

Question 12

syringia

Answer 12

mesomorphic

lilac

Question 13

Nymphea

Answer 13

hydromorphic
water lily
sclerid cells = lignified for support

stomata only on upper epidermis bc that side’s exposed

Question 14

nerium

Answer 14

xeromorphic

stomatal crypt = creates humid environment to prevent loss of water vapor

Question 15

Pinus

Answer 15

xeromorphic

• small “leaves” (pine needles) prevent water loss
• resin ducts carry protective resin substance
• endodermis around vascular bundles w/ suberin (called casparian strips –> regulate water mvmnt)

Question 16

3 photosynthetic pathways

Answer 16

C3, C4, and CAM

Question 17

2 types of photosynthetic reactions

Answer 17

Light Dependant

• in thylakoid membrane of chloroplasts
• convert solar energy to ATP or NADPH

Light Independent (Calvin Cycle)

• happens in stroma
• mesophyll cells (bundle sheath cells)
• use energy from light dependent rxns to convert CO2 into glucose and other organic stuff

Question 18

Calvin Cycle

Answer 18

1. Carbon fixation
   - CO2 combind=es with RuBP and then splits into 2 3-PGA
   - catalyzed by rubisco
2. CO2 reduction
   - ATP and NADPH turn 3-PGA into G3P
3. Regeneration
   - some G3P make glucose, and others are recycled into RuBP

Question 19

how many calvin cycles to make 1 glucose

Answer 19

6

Question 20

C3

Answer 20

• most common + energy efficient
• entire calvin cycle (including C fixation) happens in mesophyll cells

Photorespiration = high heat closes stomata –> decreases CO2 and causes O2 buildup –>Rubisco becomes oxygenase –> results in net loss of carbon

Question 21

C4

Answer 21

• super rare (3%)
• after primary fixation, makes 4-C PEP –> no tendency to bind to O2
• PEP carboxylate turns it into oxaloacetate, then maleet
• maleet is transported to bundle sheath cells
• Rubisco binds to stockpile of carbon in bundle sheath
• spatial separation
• requires more ATP than C3

Question 22

Zea mays

Answer 22

C4 plant

-has bulliform cells that make leaves curl up during drought

Question 23

CAM

Answer 23

• suculents/ orchids in dry areas
• use temporal separation of processes
• only open stomata at night
• CO2 is fixed into PEP in mesophyll cells (then oxaloacetate; then maleet)
• maleet is stored inside mesophyll vacuoles
• Daytime: CO2 is released and binds with Rubisco for calvin cycle

Question 24

sedum

Answer 24

CAM plant

big cells to hold vacuoles