Ch 6

Question 1

Leaf blade (Lamina)

Answer 1

the broad, expanded part of a leaf; not the petiole; flat, light-harvesting portion

Question 2

Petiole

Answer 2

stalk that holds the blade out into the light

Question 3

Sessile leaf base

Answer 3

leaves are small or very long and narrow, self-shading is not a problem

Question 4

Sheathing leaf base

Answer 4

the leaf base wraps around the stem

Question 5

Simple leaf

Answer 5

has a blade of just one part

Question 6

Compound leaf

Answer 6

has a blade divided into into several parts

Question 7

Leaflets

Answer 7

many small blades

Question 8

Petiolule

Answer 8

the stalk that attaches a leaflet to the rachis of a compound

Question 9

Rachis

Answer 9

the extension of the petiole in a compound leaf; all leaflets are attached to the rachis

Question 10

Veins

Answer 10

bundles of vascular tissue; distribute water from the stem to the leaf; collects sugars produced by photosynthesis and carries them to the stem for use or storage

Question 11

Reticulate Venation

Answer 11

netlike pattern of veins in a leaf, found primarily in leaves of dicots (broadleaf plants)

Question 12

Parallel Venation

Answer 12

almost exclusively in monocot leaves, a pattern in which all veins run approximately parallel to each other, either from the base of the leaf to its tip or from the midrib to the margin

Question 13

Abscission zone

Answer 13

the region at the base of an organ, such as a leaf or fruit, in which cells die and tear, permitting the organ to fall cleanly away from the stem with a minimum of damage

Question 14

Leaf scar

Answer 14

the region on a stem where a leaf was attached prior to abscission

Question 15

Epidermis

Answer 15

outermost layer of the plant primary body, covering leaves, flower parts, young stems and roots

Question 16

Transpiration

Answer 16

loss of water vapor through the epidermis

Question 17

Mesophyll

Answer 17

all tissues of a leaf except the epidermis

Question 18

Palisade parenchyma

Answer 18

any part of leaf mesophyll in which the cells are elongate and aligned parallel to each other

Question 19

Spongy mesophyll

Answer 19

any part of leaf mesophyll in which the cells are not aligned parallel to each other and are separated by large intercellular spaces

Question 20

Mid-rib veins

Answer 20

the large, central vascular bundle of a leaf

Question 21

Lateral veins

Answer 21

the major, large vascular bundles of a leaf, which are attached to the midrib or the petiole; larger than minor veins

Question 22

Minor veins

Answer 22

smallest veins of a leaf, branching off lateral veins; there is no criterion that strictly distinguishes between minor and lateral veins

Question 23

Bundle sheath

Answer 23

a set of cells, which may be parenchyma, collencyma, or sclerenchyma, that encases some or all of the vascular bundles of a leaf

Question 24

Bundle Sheath Extension

Answer 24

a set of cells, usually fibers, that extends from the bundle sheath to the upper or lower (or both) epidermis of a leaf

Question 25

Leaf Traces

Answer 25

vascular bundle that extends from the stem vascular bundles through the cortex and enters a leaf

Question 26

Stipules

Answer 26

small flaps of tissue located at the base of a leaf, near its attachment to the stem; stipules may range from quite leaflike to small and inconspiculous

Question 27

Leaf primordium

Answer 27

an extremely early stage in leaf development, when the leaf exists only as a pronounced bulging of the shoot apical meristem

Question 28

Succulent leaves

Answer 28

permits plants to survive in the desert; thick and fleshy leaves which reduces surface-to-volume ratio and favors water conservation; consequence of reducing the capacity for carbon dioxide uptake

Question 29

Sclerophyllous foliage leaves

Answer 29

must produce more sugars by photosynthesis than are used in their own construction and metabolism or the plant would lose energy every time it produced a leaf; leaves are soft, flexible, edible and less sclerenchyma

Question 30

Leaves of conifers

Answer 30

leaves are sclerophylls; they have a thick cuticle, their epidermis and hypodermis cells have thick walls; always simple and only have a few forms; needle-shaped leaves

Question 31

Bud scales

Answer 31

small specialized leaf, usually waxy or corky, that protects an unopened bud; protection; small and rarely compound

Question 32

Spines

Answer 32

modified leaves of axillary buds; protection; ie cacti; no blade and are needle shaped

Question 33

Tendrils

Answer 33

modified leaves; grow indefinitely and contain cells capable of sensing contact with an object; tendril touches something that side stops gorwing and the other side continues to elongate

Question 34

Leaves with Kranz Anatomy

Answer 34

in C4 plants; have bundle sheaths composed of large chlorophyllous cells; ring of mesophylls cells surround the sheath; adapted to arid env

Question 35

Insect traps

Answer 35

insectivory in habitats poor in nitrates and ammonia; trap leaves are either active traps that move during capture or passive traps incapable of moving