Chapter 12 - Vocabulary

Question 1

Adventitious Root

Answer 1

a root that develops from somewhere other than the root apical meristem that emerges from the seed.

Question 2

Aerenchyma

Answer 2

tissue composed of loosely packed parenchyma cells with large pores; found in aquatic plants.

Question 3

Bark

Answer 3

the protective outermost layer of the stems and roots of woody plants; consists of phloem, cork cambium, and cork.

Question 4

Blade

Answer 4

the flat part of a leaf.

Question 5

Capillary Action

Answer 5

the tendency of a liquid to rise or fall because of attractive forces between the liquid molecules.

Question 6

Carbohydrate

Answer 6

a molecule that contains only atoms of carbon, hydrogen, and oxygen in a ratio of 1:2:1.

Question 7

Casparian Strip

Answer 7

the wax-like strip that runs through the cell wall of an endodermal cell.

Question 8

Chloroplast

Answer 8

an organelle found in large numbers in many plant cells; the site of photosynthesis within a plant cell.

Question 9

Companion Cell

Answer 9

a small, nucleated phloem cell that is always associated with a sieve tube element.

Question 10

Cork Cambium

Answer 10

the meristematic layer in a woody plant that produces cork.

Question 11

Cotyledon

Answer 11

a structure in the seeds of flowering plants that stores nutrients.

Question 12

Endodermis

Answer 12

the innermost layer of cells in the cortex of a root.

Question 13

Fibrous Root System

Answer 13

a root system made up of many small, branching roots.

Question 14

Guard Cell

Answer 14

one of two kidney-shaped cells that control the opening and closing of a stoma.

Question 15

Herbaceous

Answer 15

describes plants with stems that do not have wood.

Question 16

Lateral Root

Answer 16

a smaller root that branches from a larger root.

Question 17

Meristematic Tissue (Meristem)

Answer 17

tissues consisting of dividing undifferentiated cells (meristematic cells) found in areas of the plant where growth can take place.

Question 18

Mesophyll

Answer 18

the photosynthetic middle layer of cells in the leaf of a terrestrial plant.

Question 19

Palisade Mesophyll

Answer 19

the layer of elongated photosynthetic cells arranged in columns under the upper surface of a leaf on a terrestrial plant; part of the mesophyll.

Question 20

Perforation Plate

Answer 20

the perforated end wall of a vessel element.

Question 21

Petiole

Answer 21

the stalk that attaches the leaf blade to the plant stem.

Question 22

Photopigment

Answer 22

a pigment that undergoes a physical or chemical change in the presence of light.

Question 23

Psychotropic

Answer 23

mind-altering.

Question 24

Root Cap

Answer 24

the mass of cells that form a protective covering for the meristem at the root tip.

Question 25

Root Cortex

Answer 25

a region of parenchyma cells under the epidermis of a root.

Question 26

Root Hair

Answer 26

a microscopic extension of the epidermis cells of the root.

Question 27

Root Pressure

Answer 27

the osmotic force pushing xylem sap upward in root vascular tissue.

Question 28

Sieve Cell

Answer 28

a phloem cell with pores in its cell walls; contains all necessary cell organelles.

Question 29

Sieve Plate

Answer 29

the perforated end wall of a sieve tube element.

Question 30

Sieve Tube Element

Answer 30

a phloem cell with pores in its side cell walls and a sieve plate at the end walls; sieve tube elements lack organelles and depend on associates companion cells.

Question 31

Sink

Answer 31

a plant cell with low concentration of sugars; sugars may be converted to start for storage or used rapidly for energy or as building block of other carbohydrates.

Question 32

Source

Answer 32

a plant cell with high concentration of sugars and other solutes, such as a lead cell.

Question 33

Spongy Mesophyll

Answer 33

the layer of loosely packed photosynthetic cells with large air spaces between them under the lower surface of a leaf on a terrestrial plant; part of the mesophyll.

Question 34

Stoma

Answer 34

a small opening in the epidermis of a plant that allows gas exchange.

Question 35

Taproot System

Answer 35

a root system composed of a large, thick root; can have smaller lateral roots.

Question 36

Tracheid

Answer 36

an elongated, tapered xylem cell with thick cell walls containing small pits; tracheids overlap one another at the end to form continuous tubes from root to shoot.

Question 37

Translocation

Answer 37

long-distance transport of substances through the phloem, particularly glucose.

Question 38

Transpiration

Answer 38

evaporation of water through the stomata of plant leaves.

Question 39

Tuberous Root

Answer 39

a lateral root specialized to store carbohydrates.

Question 40

Turgor

Answer 40

pressure caused by the fluid contents of the central vacuole, which pushes against the wall of a plant cell.

Question 41

Vascular Bundle

Answer 41

the arrangement of vascular tissue that consists of xylem and phloem.

Question 42

Vascular Cambium

Answer 42

the meristematic cell layer in vascular tissue.

Question 43

Vascular Cylinder

Answer 43

the central portion of a root that contains the xylem and the phloem.

Question 44

Venation

Answer 44

the arrangement of veins within a leaf.

Question 45

Vessel Element

Answer 45

a shorter, blunt-ended xylem cell with thick cell walls containing small pits; vessel elements are stacked end to end to form vessel tube that run from root to shoot.

Question 46

Woody

Answer 46

describes plants with stems that contain wood.