Vegetative Growth and Organogenesis (Lec)

Question 1

A leaf or any plant part that is equivalent to or derived from a leaf

Answer 1

Phyllome

Question 2

Areas of high cell cycle rate in the SAM

Answer 2

Flower Primordium and Flower Primoridium Initial

Question 3

SAM zone with high levels of CLAVATA3 which restricts the expression of WUSCHEL (WUS) in the shoot apical meristem to control stem cell population size to regulate the polarity

Answer 3

Central Zone

Question 4

Type of division and the structures associated with the L1, L2, and L3 zones of the SAM

Answer 4

• L1: Anticlinal division, gives rise to epidermis
• L2: Anticlinal division, gives rise to subepidermal tissues, gametes (in floral organs), and mesophyll
• L3: Both periclinal and anticlinal division, gives rise to Vascular tissues, pith, cortex, deeper tissues of the stem and leaves

Question 5

Areas of high cytokinin and gibberellin levels respectively in the SAM in leaf primordia emergence regulation

Answer 5

• Cytokinin: Central Zone
• Gibberellin: Flower Primordium, Flower Promoridium Initial, Peripheral Areas

Question 6

Genes that promote adaxial identity and repress the regulatory (maintains undifferentiation) KNOX1 gene

Answer 6

ARP Genes

Question 7

The ARP genes

Answer 7

• ASYMMETRIC LEAVES1 (AS1) in Arabidopsis
• ROUGH SHEATH2 (RS2) in maize
• PHANTASTICA (PHAN) in Antirrhinum

Question 8

Genes regulating leaf polarity for the adaxial side

Answer 8

• HD-ZIPIII: Promotes adaxial fate
• AS1/2: Represses abaxial fate genes

Question 9

Genes regulating leaf polarity for the abaxial side

Answer 9

• miR166/165: Represses HD-ZIPIII
• ARF3/4: Promotes abaxial fate
• KAN: Repress adaxial genes
• YAB: Promotes abaxial fate and leaf margin growth

Question 10

Genes regulating leaf polarity for the leaf margin

Answer 10

• PRS
• WOX1
• KLU

Question 11

Formed when the adaxial-abaxial patterning is not determined

Answer 11

Lamina Ridges

Question 12

Gene that gets de-repressed to initiate compound leaf development alongside the decline of Gibberellin levels

Answer 12

KNOX1

Question 13

Expressed in the distal boundary of the incipient leaflet to stimulate PIN1 directed auxin flow

Answer 13

CUC genes

Question 14

Epidermal cells that forms the bulk of the epidermis serving as structural protection. It is trregular, jigsaw-shaped cells

Answer 14

Pavement Cells

Question 15

Epidermal cells that are hair-like outgrowths which serve as protection against herbivores, UV, desiccation. They also function in secretion

Answer 15

Trichomes

Question 16

Epidermal cells that are involved the gas exchange

Answer 16

Guard Cells and Stomata

Question 17

Epidermal cells containing a calcium carbonate crystal serving as mechanical defense and light scattering

Answer 17

Lithocysts

Question 18

Epidermal cells that are involved in leaf folding during water stress. They are large, bubble-like cells in rows

Answer 18

Bulliform Cells

Question 19

Epidermal cells that function as defense against abrasiveness, and also functions in light reflection. They contain SiO2

Answer 19

Silica Cells

Question 20

Epidermal cells that are usually paired with silica cells

Answer 20

Cork Cells

Question 21

Proteins that synthesizes auxin to initiate vein formation

Answer 21

YUCCA Proteins

Question 22

Becomes polarized to direct auxin inward, toward the leaf base

Answer 22

PIN1

Question 23

Enhances canalization by excluding auxin from all but
a narrow zone that leads directly to the developing leaf vein

Answer 23

ABCB Exporters

Question 24

Create sinks that enhance auxin flows

Answer 24

AUX1/LAX Uptake Transporters

Question 25

Required for axillary meristem (AM) initiation, which is the source of lateral shoots or branches. It is localized to the boundary region between the shoot apical meristem (SAM) and leaf primordia

Answer 25

LAS genes

Question 26

Transported basipetally through PIN proteins, it inhibits axillary bud outgrowth by suppressing cytokinin biosynthesis in the stem and inducing strigolactone biosynthesis

Answer 26

Auxin (IAA)

Question 27

Synthesized in roots and stem tissues in response to auxin, it is acropetally transported via the xylem and inhibits branching

Answer 27

Strigolactones

Question 28

Acropetally transported through the xylem, it antagonizes the effect of auxin and strigolactones promote axillary meristem activation and bud outgrowth

Answer 28

Cytokinins

Question 29

Maintains apical dominance

Answer 29

Auxin from the shoot tip

Question 30

Regulates apical dominance

Answer 30

Sugar availability

Question 31

Key regulator in plants that adjust shoot and root architecture for efficient use of energy and nutrients, sense and adapt to nutrient levels, especially phosphorus and nitrogen, change growth patterns under stress conditions, and send signals to beneficial fungi (e.g., mycorrhizae) to form symbiotic relationships

Answer 31

Strigolactone

Question 32

Enables strigolactone by removing its repressors

Answer 32

Ubiquitin

Question 33

Monocot root system

Answer 33

Fibrous root

Question 34

Dicot root system

Answer 34

Taproot

Question 35

Type of division that adds new initials to the cambium

Answer 35

Anticlinal

Question 36

Type of divisions that produce an initial and a xylem or phloem mother cell

Answer 36

Perclinal

Question 37

Acts as a cytokinin signaling inhibitor that restricts the domain of cytokinin activity, thus allowing protoxylem differentiation in a spatially specific manner

Answer 37

AHP6