Module 7 - Epidermis

Question 1

Superficial layer of cells in young stems, roots, and foliar structures, as well as in flowers, fruits, and seeds. Undifferentiated in the apical meristem, absent in the root cap.

Answer 1

Epidermis

Question 2

Functions of the epidermis

Answer 2

Functions:

Protection

Restriction of transpiration

Storage of water and various metabolic products, absorption, and photosynthesis

Strengthen and support the plant

Restrict entry and exit of organisms and toxic substances

Question 3

Origin of the Epidermis

Answer 3

• From the outermost cell layer of the SAM
• If shoot apex has tunica corpus organization, it arises from the outermost layer of tunica
• In roots, epidermis may be related developmentally to the root cap
• Protoderm: primary meristem origin

Question 4

Haberlandtʼs term “________” is the primordial epidermis.

Others define this as undifferentiated epidermis.

Organs with little or no secondary growth usually retain the epidermis as long as they exist.

Answer 4

Protoderm

Question 5

Type of epidermis only one layer in thickness

Answer 5

Uniseriate

Question 6

Type of Epidermis with several layers of cells

Answer 6

Multiseriate

Question 7

T/F In Multiseriate Epidermis is always synchronized leading to more expanded inner than outer layers

Answer 7

False, Sometimes the division is unsynchronized leading to uneven layer thickening

Question 8

Origin of the epidermis.

Answer 8

outermost layer of tunica

Question 9

T/F The periderm is regarded as the primordial epidermis.

Answer 9

False, protoderm

Question 10

Why are the inner epidermal layers more expanded that the outer epidermal layers?

Answer 10

Asynchronous cell division

Question 11

A ground meristem derivative responsible for secreting cuticle and storing fat that resembles a multiple epidermis,

Answer 11

hypodermis

Question 12

Function of the velamen radicum

Answer 12

Storage for epiphytic plants

Question 13

Structures that prevent the widening of the stomatal aperture during stoma opening.

Answer 13

Stomatal Rings

Question 14

Give the function of hydathodes.

Answer 14

Permanently open pores for water release in the form of dew.

Question 15

Product of incomplete cell division that embeds itself into the epidermis

Answer 15

Cystolith

Question 16

T/F Velamen is dead

Answer 16

True

Question 17

Function of Velamen Radicum

Answer 17

store water and nutrients

Question 18

resemble those of a multiple epidermis but are derived from the ground meristem.

Answer 18

Hypodermis

Question 19

The cells have thin radial walls; the outer wall may be as thick or thicker than those of adjacent ordinary epidermal cells. The walls are composed of cellulose and pectic substances. The outer walls have cuticle, and the cells are highly vacuolated, containing water.

Answer 19

Bulliform Cells

Question 20

Function of Bulliform Cells

Answer 20

Prevent excess transpiration

Question 21

When guard cells are _______, the stomates are ______.

Answer 21

Turgid; open

Flaccid; closed

Question 22

Function of stomates

Answer 22

Prevent excess transpiration

Question 23

Covers the opening of the stomates under stress conditions

Answer 23

Guard Cells

Question 24

Stomate Types (According to the arrangement of the subsidiary cell around the guard cells)

Answer 24

1.Anomocytic

2.Anisocytic

3. Paracytic
4. Diacytic

5.Actinocytic

NOTE: ONLY IN DICOTS

Question 25

Characteristics of Anomocytic

Answer 25

Multiple, random arrangement

Question 26

Characteristics of anisocytic

Answer 26

Three subsidiary cells, one smaller than the rest

Question 27

Characteristics of paracytic?

Answer 27

Subsidiary cells run parallel to the guard cells

Question 28

Characteristics of diacytic

Answer 28

Subsidiary cells run perpendicular to the guard cells

Question 29

Actinocytic is defined by

Answer 29

Radial or radiating appearance of subsidiary cells

Question 30

Stomate types in Monocots

Answer 30

Type I to IV NOTE: Specific to MONOCOTS

Question 31

Guard cells are accompanied by 4-6 rectangular subsidiary cells, with 1-2 on each side (lateral SC) and 1 on each end (terminal SC). "Boxed in"

Answer 31

Type I

Question 32

Guard cells are accompanied by 4-6 subsidiary cells, with 1-2 elongated SCs on each side (lateral SCs) and 1 round SC on each end (terminal SCs). Mukhang lemon

Answer 32

Type II

Question 33

Paracytic but make it monocot

Answer 33

Type III

Question 34

Anomocytic but make it monocot

Answer 34

Type IV

Question 35

T/F Guard cells in the Gramineae and Cyperaceae (Grasses) are elongated and dumbbell-shaped.

Answer 35

True

Question 36

There are sunken areas on the leaf surface that shelter the pores from the dry wind.

Answer 36

Stomatal crypts

Question 37

Structures help minimize transpiration by breaking up the flow of air, keeping humidity higher in the crypt than in the surrounding atmosphere.

Answer 37

Trichomes

Question 38

Waxy substance on the epidermis that helps prevent transpiration

Answer 38

Cutin

Question 39

When stomata occurs on both surfaces of the leaf.

Answer 39

Amphistomatic

Question 40

When stomata occurs only on the upper side of the leaf

Answer 40

Epistomatic

Question 41

When stomata only occurs on the lower side of the leaf

Answer 41

Hypostomatic

Question 42

When all of the subsidiary or neighboring cells have a common origin with the guard cells.

Answer 42

Mesogenous

Question 43

None of the subsidiary or neighboring cells has a common origin with the guard cells.

Answer 43

Perigenous

Question 44

When at least one of the subsidiary or neighboring cells is directly related ontogenetically to the guard cells, while the others are not.

Answer 44

mesoperigenous

Question 45

These are permanently open pores at the margins and tips of leaves; they are connected to the veins and secrete droplets of liquid, called guttation drops, containing various nutrients.

Answer 45

Hydathodes

Question 46

The first protective barrier between the aerial surface of the plant and its environment is the principal barrier to the movement of water

Answer 46

Cuticle

Question 47

Cuticle has two lipid components:

Answer 47

1. insoluble cutin - in the matrix 2. soluble waxes - some in the surface of cuticle, others in matrix called cuticular wax

Question 48

Cuticle has two distinct regions

Answer 48

1. Cuticle proper - formed by cuticularization (secretion of cutin to surface of cell wall), has no cellulose 2. Cuticular layer - beneath cuticle proper, formed by cutinization (deposition of cutin between cellulose microfibrils of the outermost layers where pectin and hemicellulose may also be present)