POL sections 24.1, 25.3, 25.4, and Campbell section 7.4

Question 1

Sessile

Answer 1

Stationary

Question 2

Progression of plants

Answer 2

Aquatic Ancestors -> Simple Land Plants -> Vascular Plants

Question 3

Angiosperms

Answer 3

Flowering plants

Question 4

Plant organs are organized into ____ systems:

Answer 4

two; root system and shoot system

Question 5

Root system

Answer 5

Anchors plant in place

Question 6

Roots

Answer 6

Absorb water and dissolved minerals and store the products of photosynthesis; extreme branching of roots and their high surface area-to-volume ratios

Question 7

Shoot system

Answer 7

Cconsists of the stems, leaves, and flowers

Question 8

Leaves

Answer 8

Chief organs of photosynthesis

Question 9

Stems

Answer 9

Hold and orient the leaves to the sun and provide connections for the transport of materials between roots and leaves

Question 10

Answer 10

Question 11

Phytomer

Answer 11

Consists of a node carrying one or more leaves; an internode, which is the interval of stem between two nodes; and one or more axillary buds, each of which forms in the angle where the leaf meets the stem

Question 12

Bud

Answer 12

undeveloped shoot that can produce another leaf, a phytomer, or a flower

Question 13

Monocots

Answer 13

narrow-leaved plants such as grasses, lilies, orchids, and palms

Question 14

Eudicots

Answer 14

broad-leaved plants such as soybeans, roses, sunflowers, and maples

Question 15

four processes that govern the development of all organisms

Answer 15

determination, differentiation, morphogenesis, growth

Question 16

Determination

Answer 16

the commitment of an embryonic cell to its ultimate fate in the organism

Question 17

differentiation

Answer 17

the specialization of a cell

Question 18

morphogenesis

Answer 18

the organization and spatial distribution of cells into tissues and organs

Question 19

growth

Answer 19

increase in body size

Question 20

Meristems

Answer 20

capable of producing new roots, stems, leaves, and flowers throughout the plant’s life, enabling the plant to continue growing

Question 21

In plants, differentiated cells are _______ and most are ___________

Answer 21

pluripotent, totipotent

Question 22

Apical-basal axis

Answer 22

the arrangement of cells and tissues along the main axis from root to shoot

Question 23

Radial axis

Answer 23

the concentric (circular) arrangement of the tissue systems

Question 24

Formation of Plant Embryo Steps

Answer 24

1. Mitotic division of the zygote that gives rise to two daughter cells. Asymmetrical plane of cell division results in smaller, apical daughter cell (produces embryo proper) and larger daughter cell (produces supporting structure, suspensor). Establishes apical-basal axis

2.

In eudicots, the initially globular embryo develops into the characteristic heart stage as the cotyledons (“seed leaves”) start to grow (FIGURE 24.5, STEP 3). Further elongation of the cotyledons and of the apical–basal axis of the embryo gives rise to the torpedo stage, during which some of the internal tissues begin to differentiate (FIGURE 24.5, STEP 4). Between the cotyledons is the shoot apical meristem; at the other end of the axis is the root apical meristem. These meristems contain undifferentiated cells that will divide to give rise to the shoot and root systems.

As shown in Figure 24.5, step 2, the plant embryo is first a sphere and later a cylinder. The root and stem retain a generally cylindrical shape throughout the plant’s life. You can see this most easily in the trunk of a tree. By the end of embryogenesis, the radial axis of the plant has been established. The embryonic plant contains three tissue systems, arranged concentrically, that will give rise to the tissues of the adult plant body.

Question 25

Tissue

Answer 25

organized group of cells that have features in common and that work together as a structural and functional unit

Question 26

all vascular plants are constructed from three tissue systems:

Answer 26

dermal, vascular, and ground

Question 27

Dermal tissue system

Answer 27

forms the epidermis, or outer covering, of a plant, which usually consists of a single cell layer

Question 28

Stomata

Answer 28

pores for gas exchange in leaves

Question 29

Trichomes

Answer 29

leaf hairs, which provide protection against insects and damaging solar radiation

Question 30

Root hairs

Answer 30

greatly increase root surface area, thus providing more surface for the uptake of water and mineral nutrients

Question 31

Protective extracellular cuticle

Answer 31

Secreted by aboveground epidermal cells; consists of cutin (a polymer composed of long chains of fatty acids), a complex mixture of waxes, and cell wall polysaccharides; limits water loss

Question 32

In stems and roots of woody plants, epidermis is shet and replaced by _____

Answer 32

periderm

Question 33

ground tissue system

Answer 33

virtually all tissue lying between dermal and vascular tissue; contains three cell types: parenchyma, collenchyma, sclerenchyma

Question 34

Parenchyma cells

Answer 34

most abundant ground tissue cells. They have large vacuoles and relatively thin cell walls. They perform photosynthesis (in the shoot) and store protein (in seeds) and starch (in roots)

Question 35

Collenchyma cells

Answer 35

elongated and have unevenly thickened primary cell walls. They provide support for growing tissues such as stems

Question 36

Sclerenchyma cells

Answer 36

Have very thick secondary walls reinforced with the polyphenol polymer **lignin; **undergo programmed cell death (apoptosis); two types: fibers and sclereids;

Elongated fibers provide relatively rigid support to wood and other parts of the plant, within which they are often organized into bundles

Sclereids occur in various shapes and may pack together densely, as in a nut’s shell or in some seed coats

Question 37

Vascular Tissue system

Answer 37

plant’s plumbing or transport system—the distinguishing feature of vascular plants. Its two constituent tissues, the xylem and phloem, distribute materials throughout the plant

Question 38

Xylem

Answer 38

distributes water and mineral ions taken up by the roots to all the cells of the roots and shoots. It contains two types of conducting cells—tracheids and vessel elements

Question 39

tracheids

Answer 39

spindle-shaped cells, with thinner regions in the cell wall called pits through which water can move with little resistance from one tracheid to its neighbors

Question 40

Vessel elements

Answer 40

larger in diameter than tracheids. They meet end-to-end and partially break down their end walls, forming an open pipeline for water conduction

Question 41

Phloem

Answer 41

transports carbohydrates (primarily sugars) from sites where they are produced (called sources) to sites where they are used or stored (called sinks). Sources are often photosynthetic organs (such as leaves) but also include nonphotosynthetic storage organs (such as tubers and seeds) when they are drawn on to supply sugars to other parts of a plant. Sinks include growing tissues, roots, and developing flowers and fruit. The characteristic cells of the phloem are sieve tube elements

Question 42

Sieve tube elements

Answer 42

sieve tube elements are connected by plasmodesmata, which form a set of pores called a sieve plate. Although still alive, mature sieve tube elements have lost much of their cellular contents

Question 43

companion cells

Answer 43

adjacent, fully functional to sieve tube elements; perform many of the phloem’s metabolic functions

Question 44

Membrane Potential

Answer 44

Voltage across a membrane, ranging from -50 to -200 mV

Question 45

Electrochemical gradient

Answer 45

Combination of chemical force (concentration gradient) and electrical force (membrane potential)

Question 46

Electrogenic pump

Answer 46

Transport protein that generates voltage across a membrane

Question 47

Cotransport

Answer 47

Mechanism in which a single ATP-powered pump that transports a specific solute can indirectly drive the active transport of several other solutes

Question 48

Apoplast

Answer 48

consists of the cell walls, which lie outside the cell membranes, and intercellular spaces (spaces between cells), which are common in many plant tissues. The apoplast is a continuous meshwork through which water and solutes can flow without ever having to cross a membrane

Question 49

Symplast

Answer 49

passes through the continuous cytoplasm of the living cells connected by plasmodesmata. The selectively permeable cell membranes of the root cells control access to the symplast, so movement of water and solutes into the symplast is tightly regulated

Question 50

Casparian Strip

Answer 50

Waxy, suberin-impregnated region of the endodermal cell wall forms a hydrophobic belt around each endodermal cell where it is in contact with other endodermal cells. The Casparian strip acts as a seal that prevents water and ions from moving through spaces between the endodermal cells

Question 51

Transpiration–cohesion–tension theory

Answer 51

Transpiration: evaporation of water from cells within the leaves
Cohesion of water molecules in the xylem sap as a result of hydrogen bonding
Tension on the xylem sap resulting from transpiration

Question 52

Guard cells

Answer 52

Specialized epidermial cells that control the opening and closing of each stoma

Question 53

Translocation

Answer 53

Movement of carbohydrates and other solutes through the plant in the phloem

Question 54

Source

Answer 54

organ (such as a mature leaf or a storage root) that produces (by photosynthesis or by digestion of stored reserves) more carbohydrates than it requires

Question 55

Sink

Answer 55

organ (such as a root, flower, developing fruit or tuber, or immature leaf) that consumes carbohydrates for its own growth and storage needs

Question 56

____ surrounds _______

Answer 56

phloem; xylem

Question 57

Pressure Flow Model

Answer 57

Question 58

Two steps in phloem translocation require metabolic energy

Answer 58

Transport of sucrose and other solutes from sources into companion cells and then into the sieve tubes; called “loading”
Transport of solutes from the sieve tubes into sinks; called “unloading”