Unit 1 Intenal Organization of the Plant Body

Question 1

Meristems

Answer 1

Embryonic tissues
-Regions or populations of cells that can divide
-A continuing source of new cells
Ex: Stem cells

Question 2

What are the two parts of the meristem?

Answer 2

Apical meristem

Primary meristem

Question 3

Apical Meristem

Answer 3

Give rise to roots, stems, leaves and flowers of the adult plant

• Found in shoot and root tip
• Are composed of initials (cells that perputate the meristem–they maintain the meristem as a continuing source of new cells)

Question 4

Primary Meristem

Answer 4

Partly differentiated tissues that remain meristematic for some time

• Include the protoderm, procambium and ground tissues
• The unlimited/prolonged activity of the apical meristem means that plants have indeterminate growth

Question 5

What are the four characteristic parts of the meristem?

Answer 5

1) Development
2) Growth
3) Morphogenesis
4) Differentiation

Question 6

Development

Answer 6

Instructions in the DNA cause the process (the events that form an organisms’ body)
-The specific pathway is determined by the environment in plants

Question 7

Growth

Answer 7

Is an irreversible increase in plant size

-Caused by cell division and cell enlargement (most by this type of growth)

Question 8

Morphogenesis

Answer 8

Is the process by which a plant assumes a particular shape or form
-Accounts for morphology of different species

Question 9

Differentiation

Answer 9

Is how cells with identical genetic makeup become different from one another
-Controlled by gene expression and position in the developing organ
Ex: from a meristemic cell can become a vessel, sieve tube, fiber, or parenchyma

Question 10

What produces the tissues?

Answer 10

Apical meristems produce primary meristems that produces tissues

Question 11

What makes up the primary meristem?

Answer 11

1) Protoderm
2) Ground
3) Procambium

Question 12

What tissue system makes up the protoderm?

Answer 12

Epidermis (dermal tissue system)

Question 13

What tissue system makes up the ground?

Answer 13

Ground tissue system

-produces fibers (rigid cell wall make enzymes) and collenchyma cells (function in support)

Question 14

What tissue system makes up the procambium?

Answer 14

Vascular tissue system

Question 15

What makes up a simple tissue?

Answer 15

Made of one type of cell

-ground tissue

Question 16

What makes up a complex tissue?

Answer 16

Made of two or more types of cells

-dermal and vascular tissue

Question 17

What is primary growth of the plant?

Answer 17

• Is growth in length (height)

- Produced by apical meristems in root tip and shoot tip

Question 18

What is secondary growth of the plant?

Answer 18

• Growth in diameter

- Produced by lateral meristems

Question 19

Cork cambium

Answer 19

Produces the periderm or outer layer (part of the “bark”)

-secondary growth

Question 20

Vascular cambium

Answer 20

Produces secondary xylem (“wood”) and secondary phloem (“bark”)
-secondary growth

Question 21

Dermal Tissue

Answer 21

Outermost cell layer of the primary plant body

• This is the leaves, floral parts, fruits and seeds
• Outermost layer of roots and stems (part of this system) until they have secondary growth

Question 22

What makes up the dermal tissue?

Answer 22

• Epidermis (or periderm in woody plants)
• Cuticle
• Lacks chloroplasts

Question 23

What is the function of the epidermis?

Answer 23

• Functions in protection (mechanical)
• Aerates the internal issues through the stomata
• Is covered by a cuticle (a layer of wax-cutin and lips that covers the above ground portion of all land plants), extra protection and reduces water loss

Question 24

What are the specialized dermal cells?

Answer 24

1) Guard Cells
2) Trichomes
3) Root hairs (increase surface layer)
4) Leaf hairs (single cell-layer thick)

(2-4, functions in protection)

Question 25

What are guard cells?

Answer 25

-Contains chloroplasts -2 of them form the stomata -found at the bottom of the lower layer epidermis -openings on the surface of leaves through which water evaporates and CO2 is absorbed (when filled which H2O they open and release--> then they collapse, mechanical barrier/door)

Question 26

What makes up ground tissue?

Answer 26

Called the pith (inside the vascular tissue) and cortex (outside the vascular tissue) in stems and roots

Question 27

What cells make up the ground tissue system?

Answer 27

1) Chlorenchyma 2) Parenchyma 3) Collenchyma 4) Sclerenchyma

Question 28

Chlorenchyma

Answer 28

Parenchyma cells that contain chloroplasts

Question 29

What is the passageway of the 3 ground tissue cell types in a cell?

Answer 29

Collenchyma-->Sclerenchyma-->Parenchyma

Question 30

Parenchyma

Answer 30

Cells occur in continuous masses in the mesophyll of leaves, the cortex and pith of stems and in the flesh of fruits -cells are living at maturity

Question 31

What is the function of the parenchyma?

Answer 31

Involved in photosynthesis, storage and secretion -metabolic process (respiration) conduction, wound healing and regeneration

Question 32

Collenchyma

Answer 32

Cells are living at maturity; tissue supports young, growing organs - Occurs in discrete strands or as cylinders beneath the epidermis in stems and petioles - Cells are elongated

Question 33

What is the function of the collenchyma?

Answer 33

Supporting tissue of growing stems, leaves, and floral parts

Question 34

Sclerenchyma

Answer 34

Strengthen and support plant parts that are no longer growing - cells have thick lignified secondary walls - includes fibers and sclereids

Question 35

What is the function of fibers (sclerenchyma)?

Answer 35

Support (mature parts), storage

Question 36

What is the function of sclereid (sclerenchyma)?

Answer 36

Mechanical, protective

Question 37

Sclereids (sclerenchyma)

Answer 37

Short cells, often branched - makes up the seed coats, shells of nuts and stone cells of stone fruits (pear) - Cells can be living or dead at maturity

Question 38

What makes up the vascular tissue?

Answer 38

Xylem and Pholem

Question 39

What cells make up the xylem?

Answer 39

Tracheid and Vessel Element

Question 40

What cells make up the phloem?

Answer 40

Sieve cel, Albuminous cell, Sieve-tube element, Companion Cell

Question 41

What is the xylem?

Answer 41

Includes vessels and tracheids (conducts water and minerals) - parenchyma (storage) - fiber cells (support)

Question 42

What are water-conducting cells?

Answer 42

These are tracheids and vessel elements - Vessel elements (perforations on the end walls or the end walls dissolve completely) - Elongated cells with secondary walls that lack protoplasts at maturity - May have pits in their walls - Found in gnetophytes and angiosperms

Question 43

2 types of xylem development

Answer 43

1) Protoxylem | 2) metaxylem

Question 44

Protoxylem

Answer 44

First part of the xylem system - Cells are smaller in diameter - Secondary walls (have rings or spiral thickenings); makes it possible to stretch or extend the cell as it elongates (narrow in diameter)

Question 45

Metaxylem

Answer 45

Differentiates after the protoxylem; after the plant part | -cells are rigid and cannot be stretched (wider in diameter)

Question 46

Tracheid

Answer 46

- Xylem - elongated and tapering - contains pits but no perforations - dead when functional - water-conducting cell in mostly gymnosperms, a few seedless vascular plants and some in angiosperms

Question 47

Vessel Element

Answer 47

- Xylem - elongated (shorter than a tracheid) - contains pits and perforations - dead when functional - water-conducting cell in angiosperms

Question 48

What is the phloem?

Answer 48

Includes sieve-tube elements with companion cells (long-distance transport), sclerenchyma (support), and parenchyma (storage) -Is principal food conducting tissue in the plant (transports sugars, amino acids, lipids, hormones, micronutrients, proteins and RNA)

Question 49

Sieve Plates

Answer 49

Slime plug may result during sectioning of sieve-tube element

Question 50

Sieve Cell

Answer 50

- Pholem - elongated and tapering - living at maturity - food-conducting element in gymnosperms

Question 51

Albuminous Cell

Answer 51

- Pholem - elongated and living at maturity - Plays a role in the delivery of substances to the sieve cell (informational molecules and ATP)

Question 52

Sieve-tube Element

Answer 52

- Pholem - elongated and living at maturity - Food-conducting element in angiosperms

Question 53

Companion Cell

Answer 53

- Pholem - generally elongated and living at maturity - Plays a role in the delivery of substances to the sieve-tube element (informational molecules and ATP)