UNIT 5: PLANT LEAVES w/o Phyllotaxy

Question 1

Functions

Answer 1

1. Manufacture of food through
   photosynthesis
2. Gas exchange via respiration
3. Protect vegetative and floral buds
4. Water transport via transpiration - The loss of water vapor through the stomata of leaves.
5. Store food during germination
6. Horticultural uses
   - Food
   - Herb
   - Compost
   - Summer cooling
   - Medicinal uses
   - Wind, dust, noise reduction
   - Aesthetic qualities
   - Plant identification
   - Beverage
   - Propagation from cuttings
   - Wildlife habitat
   - Aromatic oils and wax

Question 2

a process occurring in the leaves wherein food is manufactured from water and CO2, with the aid of chlorophyll in the presence of light energy (sunlight or artificial light)

6 CO2 + 12 H2O ——–> C6H12O6 + 6 O2 + 6H2O
light energy glucose

Answer 2

Photosynthesis

Question 3

Essential factors in photosynthesis –any factor whose presence is required to initiate a reaction

If one of these factors is absent, the reaction will not proceed

1. Raw materials – _________
   a. _____ through the _____
   b. _____ through the _____

Answer 3

substrates

a. CO2 through the stomates
b. H2O through the roots

Question 4

primarily from the sun but electric light can also be used

• needed to convert simple molecules to more complex ones

Answer 4

energy (light energy)

Question 5

1. Pigments –especially _________

– chloroplast: ______ & ________

• ______: contains chlorophyll (green pigment)
• where light reaction of photosynthesis takes place
• ______: contains enzymes
• where the dark reaction
  takes place

Answer 5

• chlorophyll
• grana and stroma

grana

stroma

Question 6

Optimum temperature
– ___ to ___ degrees Celsius

The rate of photosynthesis is increased as the temperature increases up to 35 degrees (beyond 35 degrees)

Answer 6

5 to 40 degrees celsius

Question 7

2 steps of Photosynthesis

Answer 7

light reaction
dark reaction

Question 8

• light dependent reaction
• occurs in the granum of the chloroplasts

Answer 8

light reaction

Question 9

• light independent reaction
• occurs in the stroma

Answer 9

dark reaction

Question 10

• Produce sugar from light energy
• Stores energy
• Occurs only in cells with chloroplasts
• Releases oxygen
• Uses water
• Uses carbon dioxide
• Requires light

Answer 10

photosynthesis

Question 11

• Burns sugars for energy
• Releases energy
• Occurs in most cells
• Uses oxygen
• Produces water
• Produces carbon dioxide
• Occurs in dark and light

Answer 11

respiration

Question 12

parts of leaves

Answer 12

BLADE
- apex
- margin
- veins
- midrib
- base

petiole
axillary bud
stipule
stem

Question 13

external structure of leaves

Answer 13

leaf blade
petiole
veins
node
axillary bud
stipule
margin

Question 14

Wide flattened area of leaf for concentrating sunlight on photosynthetic cells

Answer 14

leaf blade

Question 15

Short stem that attaches leaf to main stem or branch

Answer 15

petiole

Question 16

Vascular bundles within leaf for transport

Answer 16

veins

Question 17

Growth region of stem where leaves or new branches arise

Answer 17

node

Question 18

Baby leaf or stem

Answer 18

axillary bud

Question 19

Leaflike outgrowths usually present in pairs at the base of the petiole

Answer 19

stipule

Question 20

edge of the leaf

Answer 20

margin

Question 21

For plant identification purposes, the _________, _________, & __________ are key features to note.

Remember, a leaf begins at the _________ or __________.

Answer 21

shape of the leaf margin, leaf tip and leaf base

lateral or auxiliary bud

Question 22

dicot leaf

Answer 22

• petiole
• veins
• leaf blade

where leaf would be attached to the branch or stem at the node

Question 23

monocot leaf

Answer 23

• sheath
• ligule
• auricle
• collar

Question 24

part of leaf that holds leaf to stem –encases stem

Answer 24

sheath

Question 25

membrane-like tissue extending up from the sheath (on inside) –keeps dirt and moisture out –clear membrane on leaf where attaches to stem

Answer 25

ligule

Question 26

small appendages that extend out and sometimes around the stem –found at the junction of the blade and sheath –can be clasping or non clasping appendages

Answer 26

auricle

Question 27

area between the leaf blade and sheath –auricles and ligules are on the inside of this area

Answer 27

collar

Question 28

- blade-like leaf blade – wrapped around the stem – no petiole – have main vascular bundles running parallel along length of leaf

Answer 28

monocot leaf

Question 29

- have both a leaf blade and a petiole – single midrib (Vascular bundles) with branches

Answer 29

dicot leaf

Question 30

INTERNAL STRUCTURE OF LEAVES

Answer 30

1. epidermis - upper and lower - stomata 2. mesophyll - palisade layer - spongy layer 3. veins of vascular bundles

Question 31

- outermost single layer of the leaf that consists of flattened and transparent cells which permits unobstructed sunlight to enter the underlying photosynthetic cells - cell walls contain ______ in a continuous layer called ______. - thin in plants in moist habitats and thicker in dry areas to prevent rapid transpiration 2 types

Answer 31

- cutin - cuticle upper and lower epidermis EPIDERMIS

Question 32

- has a thicker cuticle because it is the exposed part to the sun - lesser stomata to prevent rapid transpiration

Answer 32

upper epidermis

Question 33

- thinner cuticle and contains more stomata

Answer 33

lower epidermis

Question 34

- contain guard cells to regulate the opening of the stomatal pore - in darkness, the guard cells are limp and the stomates are closed - in the presence of light, the guard cells are turgid because they absorb water and the stomates are open

Answer 34

stomata

Question 35

* Turgidity of the __________ will determine the closing and opening of the cell

Answer 35

guard cells

Question 36

the middle part of the leaf, rich in chlorophyll, usually surrounded by bundle sheaths and is composed by two distinct tissues:

Answer 36

palisade layer spongy layer MESOPHYLL

Question 37

– the upper layer, vertically elongated and compactly arranged parenchyma cells lying just below the upper epidermis * ______________: chief photosynthetic cells of the plant

Answer 37

Chlorenchyma cells PALISADE LAYER

Question 38

lower layer made up of loosely arranged cells of variable forms

Answer 38

SPONGY LAYER

Question 39

- branched continuations of the vascular bundles of the petiole and midrib that consists of the xylem and phloem - in most leaves, the xylem is in the upper part of the veins while the phloem is in the lower part

Answer 39

VEINS OF THE VASCULAR BUNDLES

Question 40

LEAF TYPES

Answer 40

1. conifer 2. ginkgo 3. dicot 4. monocot

Question 41

The leaves of conifers are needle-like (as on pines) or scale-like (as on junipers (Juniperus) – Each conifer leaf has a single vein

Answer 41

conifer

Question 42

unique plant having fan-shaped leaf blades with dichotomous venation in which the veins branch into two equal or unequal lengths.

Answer 42

ginkgo

Question 43

Most of these blades have pinnate (feather-like) venation in which major veins diverge from one large mid-vein, with smaller network connections between

Answer 43

dicot

Question 44

With parallel venation, major veins arise at the base, remain more or less parallel, and converge at the tip with small vein interconnections

Answer 44

monocot

Question 45

LEAF ATTACHMENT

Answer 45

1. petiolate 2. sessile

Question 46

The leaf blade is attached to the stem by a stalk called a petiole

Answer 46

petiolate

Question 47

When the leaf blade is attached directly to the stem without a petiole

Answer 47

sessile

Question 48

specialized or modified leaves

Answer 48

1. tendrils 2. prickles and thorns 3. storage leaves/succulent leaves 4. reproductive leaves 5. insect-trapping leaves 6. colorful bracts 7. winged petiole 8. enlarged petiole

Question 49

- blade of leaves or leaflets are reduced in size, allows plant to cling to other objects - sweet pea and garden peas

Answer 49

tendrils

Question 50

- epidermal outgrowths on stems and leaves - holly, rose, and raspberries

Answer 50

prickles and thorns

Question 51

retain water in large vacuoles

Answer 51

storage leaves/succulent leaves

Question 52

- Kalanchöe plantlets arise on margins of leaves

Answer 52

reproductive leaves

Question 53

- pitcher plants, sundews, venus flytraps, and bladderworts - have modified leaves for capturing insects - all these plants live under nutrient-poor conditions and digest insect bodies to obtain nitrogen and other essential nutrients

Answer 53

insect-trapping leaves

Question 54

petal-like leaves

Answer 54

colorful bracts

Question 55

additional surface area for photosynthesis - Citrus plants

Answer 55

winged petiole

Question 56

- petiole is enlarged and filled with air for buoyancy - Water hyacinth

Answer 56

enlarged petiole