Chapter 23 vocabulary

Question 1

apical meristem

Answer 1

found at the tips of all roots and stems and are involved primarily with extension of the pant body (greek, merismos, division)

Question 2

initials

Answer 2

cells that maintain the meristem as a continuing source of new cells. divide in such a way that one of the sister cells reamins in the meristem as an initial while the other becomes a new body cell.

Question 3

derivative

Answer 3

sister cells of the intitials that become new body cells

Question 4

What three overlapping processes make up development?

Answer 4

1. growth
2. morphogenesis
3. differentiation

Question 5

Development occurs in response to…

Answer 5

instructions contained in the genetic information that an organism inherits from its parents.

Question 6

in plants, the specific developmental pathway is determined by

Answer 6

position of cells and tissues within the apical-basal and radial patterns.
environmental factors (daylength, light quality and quantity, temperature, and gravity.

Question 7

growth

Answer 7

an irreversible increase in size; a combination of cell division and cell enlargement

Question 8

most plant growth is brought about by…

Answer 8

cell enlargement.

Question 9

morphogenesis

Answer 9

(greek, shape and origin) the development of form

Question 10

The primary event in morphogenesis is…

Answer 10

the expansion of tissue.

Question 11

Differentiation

Answer 11

the process by which cells with identical genetic constitution become different from one another and form the meristematic cells from which they originated. begins while cell is still enlarging

Question 12

differentiation depends on…

Answer 12

the control of gene expression.

Question 13

What is the fate of a plant cell determined by?

Answer 13

the final position in the developing organ.

Question 14

True or false. Cells communicate positional information to other surrounding cells.

Answer 14

True.

Question 15

determination

Answer 15

progressive commitment to a specific course of development that brings about a weakening or loss of capacity to resume growth.

Question 16

competency

Answer 16

the ability of a cell to develop in response to a specific signal, such as light.

Question 17

What are the simple tissues?

Answer 17

parenchyma, collenchyma, and sclerenchyma

Question 18

What are the complex tissues?

Answer 18

xylem, phloem, epidermis, and periderm.

Question 19

True or False. The pith is located only in the stem.

Answer 19

true.

Question 20

True or False. the pith is located in the leaf.

Answer 20

False. the mesophyll is in the leaf

Question 21

What processes are parenchymal tissue involved in?

Answer 21

photosynthesis, storage, and secretion

Question 22

Where are parenchymal cells located?

Answer 22

in the cortex and pith of stems and roots, and in leaf mesophyll, and in the flesh of fruits.

Question 23

Which basic cell type are most numerous in the body?

Answer 23

parenchymal cells

Question 24

where else do parenchymal cells reside in the plant? (hard question.)

Answer 24

they occur as vertical strands of cells in the primary and secondary vascular tissues and as horizontal strands called rays in the secondary vascular tissues.

Question 25

True or False. Parenchymal cells initiate adventitious structures, such as adventitious roots on stem cuttings.

Answer 25

true.

Question 26

parenchymal cells are totipotent, meaning...

Answer 26

they have the ability to become embryonic cells and to develop into an entire plant.

Question 27

transfer cells

Answer 27

cell wall ingrowths that serve to increase the surface area of the plasma membrane; helps facilitate movement of solutes over short distances.

Question 28

True or False. the presence of transfer cells is generally not correlated with the existence of intensive movement of solutes, by uptake or secretion, across the plasma membrane.

Answer 28

False. they are generally correlated to solute movement.

Question 29

True or False. Collenchyma and parenchymal cells both are living at maturity.

Answer 29

True.

Question 30

What is the most distinctive structure of collenchyma?

Answer 30

unevenly thickened, nonlignified primary walls

Question 31

Collenchyma is the typical supporting tissue of...

Answer 31

growing stems, leaves, and floral parts and of most herbaceous (non-woody) organs that undergo little or no secondary growth.

Question 32

True or false. roots rarely have collenchyma.

Answer 32

true.

Question 33

True or false. collenchyma is absent in stems and leaves of many monocots that form sclerenchyma early in their development.

Answer 33

True.

Question 34

True or False. collenchyma support young, growing organs and therefore, tend to elongate.

Answer 34

True.

Question 35

True or False. Sclerenchyma tissues strengthen and support plant parts that are no longer elongating.

Answer 35

True.

Question 36

Where can sclerenchyma devleop?

Answer 36

in any or all parts of the primary and secondary plant bodies.

Question 37

True or false. Schlerenchyma have protoplasts at maturity.

Answer 37

False. they often lack them.

Question 38

the principal characteristic of schlerenchyma is...

Answer 38

their thick, often lignified, secondary walls.

Question 39

What are the two types of schlerenchyma cells?

Answer 39

Fibers and schlereids.

Question 40

What are fibers?

Answer 40

long, slender cells that occur in strands or bundles.

Question 41

Sclereids are...

Answer 41

variable in shape and often branched.

Question 42

Sclereids make up....

Answer 42

seed coats of many seeds, the shells of nuts, and the stone (endocarp) of stone fruits, such as olives, peaches, and cherries, and they give pears their characteristic gritty texture.

Question 43

What is the principal water conducting tissue in the vascular system?

Answer 43

xylem

Question 44

What three functions, other than water conduction, is the xylem involved in?

Answer 44

conduction of minerals, in support, and in food storage.

Question 45

What are the principal conducting cells of the xylem?

Answer 45

tracheary elements

Question 46

What are the two kinds of tracheary elements?

Answer 46

tracheids and the vessel elements.

Question 47

What do traceids and the vessel elements have in common?

Answer 47

both are elongated cells that have secondary walls and lack protoplasts at maturity, and both may have pits in their walls.

Question 48

What are pits?

Answer 48

areas lacking secondary walls, in tracheids and the vessel elements.

Question 49

Unlike tracheids, vessel elements contain what?

Answer 49

perforations, areas lacking in both primary and secondary cell walls.

Question 50

What is the part of the cell wall bearing the perforation or perforations?

Answer 50

the perforation plate.

Question 51

Where do perforations generally occur?

Answer 51

on the end walls, with the vessel elements joined end-to-end, forming vessels.

Question 52

What are vessels?

Answer 52

long, continuous columns or tubes created by perforations.

Question 53

What is the principal water-conducting cell in angiosperms?

Answer 53

the vessel elements.

Question 54

What is the only type of water conducting cell found in seedless vascular plants and gymnosperms?

Answer 54

tracheids.

Question 55

True or False. the xylem of many angiosperms contain both vessel elements and tracheids.

Answer 55

true.

Question 56

What are more efficient water conductors? Tracheids, or vessel elements?

Answer 56

vessel elements.

Question 57

Which type of water conducting cell is better at containing air bubbles?

Answer 57

tracheids.

Question 58

What makes it possible for the tracheids to stretch or extend after cells have differentiated?

Answer 58

annular/helical thickenings.

Question 59

True or False. the primary xylem's wall thickening is greatly influenced by the amount if elongation.

Answer 59

True. little elongation results in nonextensible, rather than extensible elements.

Question 60

In the metaxylem and secondary xylem, the secondary cells walls of the tracheids and vessel elements cover the entire primary walls, except...

Answer 60

at the pit membranes and at the perforations of the vessel elements, which are called pitted elements, and are rigid and cannot be stretched.

Question 61

What is programmed cell death?

Answer 61

the outcome of genetically programmed processes that result in cell death.

Question 62

What is an example of programmed cell death?

Answer 62

tracheary element differentiation

Question 63

What is the principal food conducting tissue in vascular plants?

Answer 63

the phloem.

Question 64

Other than sugars, what does the phloem transport?

Answer 64

amino acids, lipids, micronutrients, hormones, the floral stimulus, (florigen) and numerous proteins and RNAs, some of which serve as signaling molecules.

Question 65

True or false. short-distance signaling in plants occurs predominantly through the phloem.

Answer 65

False. Long-distance signaling does.

Question 66

True or False. the phloem is the route for movement of a range of plant viruses.

Answer 66

True.

Question 67

What are the principal conducting cells of the phloem?

Answer 67

sieve elements

Question 68

What are sieve elements?

Answer 68

the cells of the phloem that are involved in the long-distance transport of food substances.

Question 69

what are sieve areas?

Answer 69

clusters of pores through which the protoplasts of adjacent sieve elements are interconnected.

Question 70

what are the two types of sieve elements found in seed plants?

Answer 70

sieve cells, and sieve-tube elements.

Question 71

What is the only food conducting cell in gemiosperms?

Answer 71

sieve cells

Question 72

Which sieve element occurs in angiosperms?

Answer 72

sieve-tube elements.

Question 73

In sieve cells, the sieve area pores are...

Answer 73

narrow and the sieve areas are uniform in structure on all walls.

Question 74

In sieve-tube elements, the sieve areas...

Answer 74

on some walls have larger pores than those on other walls of the same cell.

Question 75

What is a sieve plate?

Answer 75

the part of the wall bearing the sieve areas with larger pores.

Question 76

Where are sieve plates generally located?

Answer 76

on end walls

Question 77

True or False. The presence of sieve plates is a defining characteristic of...

Answer 77

sieve elements, and are not found in sieve cells.

Question 78

What is callose?

Answer 78

a polysaccharide composed of spirally wound chains of glucose residues.

Question 79

Most of the callose seen in the pores of conducting sieve elements are deposited there in response to...

Answer 79

injury during preparation of the tissue for microscopy.

Question 80

True or False. callose also shows in the form of platelets beneath the plasma membrane around each plasmodesma at the site of developing sieve-plate pores.

Answer 80

True.

Question 81

True or False. unlike tracheary elements, sieve elements have living protoplasts at maturity.

Answer 81

True.

Question 82

The protoplasts of the sieve-tube elements of angiosperms, are characterized by the presence of...

Answer 82

P protein (once called slime.)

Question 83

What is a forisome?

Answer 83

a single, nondispersive P-protein body found in legumes, that undergo rapid and reversible calcium-controlled changes in which they occlude the sieve-plate pores.

Question 84

Sieve-tube elements are usually associated with specialized parenchyma cells called...

Answer 84

companion cells.

Question 85

What is the life support cell of sieve-tube elements?

Answer 85

companion cells

Question 86

in gymnosperms, sieve-tube elements are associated with a different cell that serves the same function as companion cells. What are these cells called?

Answer 86

Albuminous cells/Strasburger cells

Question 87

What is the difference between companion and albuminous cells?

Answer 87

companion cells come from the same mother cells, whereas albuminous cells (Strasburger cells) do not.

Question 88

The epidermis contains...

Answer 88

guard cells, many types of appendages, or trichomes and other types of specialized cells.

Question 89

What is responsible for the whitish or bluish "bloom" on the surface of some leaves and fruits?

Answer 89

epicuticular wax

Question 90

This is the site of light perception involved in circadian leaf movement and photoperiodic induction.

Answer 90

epidermis

Question 91

Guard cells contain....

Answer 91

chloroplasts.

Question 92

Guard cells regulate stomata, in the aerial parts of the plants and thus...

Answer 92

control the exchange of gases, including water vapor, into and out of those pores.

Question 93

Where are stomata most abundant?

Answer 93

leaves

Question 94

true or false. Guard cells are often associated with subsidiary cells.

Answer 94

True.

Question 95

What is the periderm?

Answer 95

it commonly replaces the epidermis in stems and roots that undergo secondary growth.

Question 96

What cells in the periderm are loosely arranged and provide for aeration of the internal tissues of roots and stems?

Answer 96

lenticels

Question 97

The periderm consists of these three parts:

Answer 97

phellem (protective, non-living cork) phellogen or cork cambium phelloderm (a living parenchyma-like tissue)

Question 98

Look at the chart on page 556-557 and practice memorizing it.

Answer 98

ok.