Chapter 35

Question 1

A living cell that conducts sugars and other organic nutrients in the phloem of angiosperms; also called a sieve-tube member. Connected end to end, they form sieve tubes.

Answer 1

sieve-tube element

Question 2

A type of plant cell that is connected to a sieve-tube element by many plasmodesmata and whose nucleus and ribosomes may serve one or more adjacent sieve-tube elements.

Answer 2

companion cell

Question 3

(1) The dermal tissue system of nonwoody plants, usually consisting of a single layer of tightly packed cells. (2) The outermost layer of cells in an animal.

Answer 3

epidermis

Question 4

A model of flower formation identifying three classes of organ identity genes that direct formation of the four types of floral organs.

Answer 4

ABC hypothesis

Question 5

A tiny extension of a root epidermal cell, growing just behind the root tip and increasing surface area for absorption of water and minerals.

Answer 5

root hair

Question 6

A root that arises from the pericycle of an established root.

Answer 6

lateral root

Question 7

The vascular tissue of a stem or root.

Answer 7

stele

Question 8

(1) The outer region of cytoplasm in a eukaryotic cell, lying just under the plasma membrane, that has a more gel-like consistency than the inner regions due to the presence of multiple microfilaments. (2) In plants, ground tissue that is between the vascular tissue and dermal tissue in a root or eudicot stem.

Answer 8

cortex

Question 9

The outer protective covering of plants.

Answer 9

dermal tissue system

Question 10

A transport system formed by xylem and phloem throughout a vascular plant. Xylem transports water and minerals; phloem transports sugars, the products of photosynthesis.

Answer 10

vascular tissue system

Question 11

Ground tissue that is internal to the vascular tissue in a stem; in many monocot roots, parenchyma cells that form the central core of the vascular cylinder.

Answer 11

pith

Question 12

A type of growth characteristic of most animals and some plant organs, in which growth stops after a certain size is reached.

Answer 12

determinate growth

Question 13

(1) A shift from one developmental phase to another. (2) In plants, a morphological change that arises from a transition in shoot apical meristem activity.

Answer 13

phase change

Question 14

Growth produced by apical meristems, lengthening stems and roots.

Answer 14

primary growth

Question 15

An organ in vascular plants that anchors the plant and enables it to absorb water and minerals from the soil.

Answer 15

root

Question 16

The two cells that flank the stomatal pore and regulate the opening and closing of the pore.

Answer 16

guard cells

Question 17

Leaf cells specialized for photosynthesis. In C3 and CAM plants, mesophyll cells are located between the upper and lower epidermis; in C4 plants, they are located between the bundle-sheath cells and the epidermis.

Answer 17

mesophyll

Question 18

A strong polymer embedded in the cellulose matrix of the secondary cell walls of vascular plants that provides structural support in terrestrial species.

Answer 18

lignin

Question 19

In plant roots, the innermost layer of the cortex that surrounds the vascular cylinder.

Answer 19

endodermis

Question 20

A bud at the tip of a plant stem; also called a terminal bud.

Answer 20

apical bud

Question 21

A plant gene that promotes the switch from vegetative growth to flowering.

Answer 21

meristem identity gene

Question 22

A cone of cells at the tip of a plant root that protects the apical meristem.

Answer 22

root cap

Question 23

A continuous water-conducting micropipe found in most angiosperms and a few nonflowering vascular plants.

Answer 23

vessel

Question 24

A short, wide water-conducting cell found in the xylem of most angiosperms and a few nonflowering vascular plants. Dead at maturity, vessel elements are aligned end to end to form micropipes called vessels.

Answer 24

vessel element

Question 25

All tissues external to the vascular cambium, consisting mainly of the secondary phloem and layers of periderm.

Answer 25

bark

Question 26

A main vertical root that develops from an embryonic root and gives rise to lateral (branch) roots.

Answer 26

taproot

Question 27

A cylinder of meristematic tissue in woody plants that adds layers of secondary vascular tissue called secondary xylem (wood) and secondary phloem.

Answer 27

vascular cambium

Question 28

A segment of a plant stem between the points where leaves are attached.

Answer 28

internode

Question 29

A meristem that thickens the roots and shoots of woody plants. The vascular cambium and cork cambium are lateral meristems.

Answer 29

lateral meristem

Question 30

(1) A leaflike structure of a seaweed that provides most of the surface area for photosynthesis. (2) The flattened portion of a typical leaf.

Answer 30

blade

Question 31

A short, irregular sclerenchyma cell in nutshells and seed coats. Sclereids are scattered throughout the parenchyma of some plants.

Answer 31

sclereid

Question 32

Plant tissues that are neither vascular nor dermal, fulfilling a variety of functions, such as storage, photosynthesis, and support.

Answer 32

ground tissue system

Question 33

A long, tapered water-conducting cell found in the xylem of nearly all vascular plants. Functioning tracheids are no longer living.

Answer 33

tracheid

Question 34

Plant tissue that remains embryonic as long as the plant lives, allowing for indeterminate growth.

Answer 34

meristem

Question 35

Vascular plant tissue consisting of living cells arranged into elongated tubes that transport sugar and other organic nutrients throughout the plant.

Answer 35

phloem

Question 36

A lignified cell type that reinforces the xylem of angiosperms and functions in mechanical support; a slender, tapered sclerenchyma cell that usually occurs in bundles.

Answer 36

fiber

Question 37

A structure that has the potential to form a lateral shoot, or branch. The bud appears in the angle formed between a leaf and a stem.

Answer 37

axillary bud

Question 38

Growth produced by lateral meristems, thickening the roots and shoots of woody plants.

Answer 38

secondary growth

Question 39

A flexible plant cell type that occurs in strands or cylinders that support young parts of the plant without restraining growth.

Answer 39

collenchyma cell

Question 40

A rigid, supportive plant cell type usually lacking a protoplast and possessing thick secondary walls strengthened by lignin at maturity.

Answer 40

sclerenchyma cell

Question 41

A relatively unspecialized plant cell type that carries out most of the metabolism, synthesizes and stores organic products, and develops into a more differentiated cell type.

Answer 41

parenchyma cell

Question 42

The development of a multicellular organism’s spatial organization, the arrangement of organs and tissues in their characteristic places in three-dimensional space.

Answer 42

pattern formation

Question 43

Embryonic plant tissue in the tips of roots and buds of shoots. The dividing cells of an apical meristem enable the plant to grow in length.

Answer 43

apical meristem

Question 44

The events involved in an organism’s changing gradually from a simple to a more complex or specialized form.

Answer 44

development

Question 45

A vascular plant organ consisting of an alternating system of nodes and internodes that support the leaves and reproductive structures.

Answer 45

stem

Question 46

Tendency for growth to be concentrated at the tip of a plant shoot, because the apical bud partially inhibits axillary bud growth.

Answer 46

apical dominance

Question 47

A fingerlike projection along the flank of a shoot apical meristem, from which a leaf arises.

Answer 47

leaf primordium

Question 48

A lack of symmetry; structural differences in opposite ends of an organism or structure, such as the root end and shoot end of a plant.

Answer 48

polarity

Question 49

All of a plant’s roots, which anchor it in the soil, absorb and transport minerals and water, and store food.

Answer 49

root system

Question 50

The stalk of a leaf, which joins the leaf to a node of the stem.

Answer 50

petiole

Question 51

An integrated group of cells with a common structure, function, or both.

Answer 51

tissue

Question 52

Vascular plant tissue consisting mainly of tubular dead cells that conduct most of the water and minerals upward from the roots to the rest of the plant.

Answer 52

xylem

Question 53

A cylinder of meristematic tissue in woody plants that replaces the epidermis with thicker, tougher cork cells.

Answer 53

cork cambium

Question 54

One or more tissues organized into a functional unit connecting the organs of a plant.

Answer 54

tissue system

Question 55

A type of growth characteristic of plants, in which the organism continues to grow as long as it lives.

Answer 55

indeterminate growth

Question 56

A point along the stem of a plant at which leaves are attached.

Answer 56

node

Question 57

A plant homeotic gene that uses positional information to determine which emerging leaves develop into which types of floral organs.

Answer 57

organ identity gene

Question 58

The protective coat that replaces the epidermis in woody plants during secondary growth, formed of the cork and cork cambium.

Answer 58

periderm

Question 59

A small raised area in the bark of stems and roots that enables gas exchange between living cells and the outside air.

Answer 59

lenticel

Question 60

An end wall in a sieve-tube element, which facilitates the flow of phloem sap in angiosperm sieve tubes.

Answer 60

sieve plate

Question 61

A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant.

Answer 61

stoma

Question 62

The aerial portion of a plant body, consisting of stems, leaves, and (in angiosperms) flowers.

Answer 62

shoot system