lab 4 terms

Question 1

phyllotaxy

Answer 1

the arrangement of leaves on a stem

Question 2

alternate phyllotaxy

Answer 2

leaf arrangement where there is one leaf per node; there are two types of alternate phyllotaxy: alternate distichous and alternate spiral

Question 3

alternate distichous phyllotaxy

Answer 3

leaf arrangement where there is one leaf per node and leaves are arranged in two rows, 180 degrees from each other; leaves are in a single plane

Question 4

alternate spiral phyllotaxy

Answer 4

leaf arrangement where there is one leaf per node and leaves are arranged in a spiral around the stem

Question 5

opposite phyllotaxy

Answer 5

leaf arrangement where there are two leaves per node and leaves are arranged in pairs across the stem from each other; there are two types of opposite phyllotaxy: opposite distichous and opposite decussate

Question 6

opposite distichous phyllotaxy

Answer 6

leaf arrangement where there are two leaves per node and leaves are arranged in pairs across the stem from each other; pairs of leaves are in a single plane

Question 7

opposite decussate phyllotaxy

Answer 7

leaf arrangement where there are two leaves per node and leaves are arranged in pairs across the stem from each other; successive pairs of leaves are at right angles to one another

Question 8

whorled phyllotaxy

Answer 8

leaf arrangement where there are three or more leaves per node

Question 9

venation

Answer 9

the pattern of veins within a leaf

Question 10

pinnate reticulate venation

Answer 10

the pattern of veins within a leaf where there is a midrib and veins branch from it with larger veins branching into smaller veins

Question 11

reticulate (netted) venation

Answer 11

the pattern of veins within a leaf where the veins form a network, branching from larger to smaller veins; characteristic of eudicots

Question 12

palmate reticulate venation

Answer 12

the pattern of veins within a leaf where there are several large veins (no midrib) branching from the top of the petiole that branch into smaller and smaller veins

Question 13

adaxial surface

Answer 13

the upper surface of the leaf

Question 14

abaxial surface

Answer 14

the lower surface of the leaf

Question 15

leaf sheath

Answer 15

part of a leaf in some monocots (grasses); the base of the leaf that wraps around the stem

Question 16

parallel venation

Answer 16

the pattern of veins within a leaf where there is usually a midrib with several other large veins running parallel to it for the length of the leaf blade; there are typically many tiny cross veins that join the parallel veins along their length; characteristic of monocots

Question 17

ligule

Answer 17

a small outgrowth of a monocot (grass) leaf at the point where the leaf blade meets the leaf sheath

Question 18

simple leaf

Answer 18

a leaf where the blade is not divided into distinct parts

Question 19

compound leaf

Answer 19

a leaf where the blade is divided into leaflets, usually each with its own small stalk

Question 20

pinnately compound leaf

Answer 20

a compound leaf where the leaflets arise from other side of an axis, the rachis (resembles a feather)

Question 21

palmately compound leaf

Answer 21

a compound leaf where the leaflets all arise from the top of the petiole (there is no rachis)

Question 22

leaflet

Answer 22

one of the part of the blade of a compound leaf

Question 23

rachis

Answer 23

the central axis of a pinnately compound lead to which the leaflets attach

Question 24

stipule

Answer 24

an outgrowth from the base of the petiole of a leaf; often in pairs

Question 25

sessile leaf

Answer 25

a leaf which lacks a petiole; the blade attaches directly to the node

Question 26

photosynthesis

Answer 26

the conversion of light energy to chemical energy; the production of carbohydrates from CO2 and water in the presence of light and chlorophyll, using light energy

Question 27

tendril

Answer 27

a modified leaf or leaflet (or stem); modified into a slender, coiling structure which grows around other plants or objects to help support the plant

Question 28

spine

Answer 28

a modified leaf; modified into a hard, sharp-pointed structure; often for protection from herbivores

Question 29

prickle

Answer 29

a sharp, pointed outgrowth of the epidermis of a leaf or stem (a rose’s ‘thorns’ are actually prickles); for protection from herbivores

Question 30

bulb

Answer 30

a specialized underground bud with thick, fleshy leaves (both the leaves and the stem are modified); the bulb functions in vegetative reproduction - the leaves of the bulb function in food storage

Question 31

bud scale

Answer 31

small, hard leaves which surround and protect shoot buds (often over the winter)

Question 32

carnivorous plant

Answer 32

plants with leaves modified in a variety of ways to entrap insects to enhance nutrition (venus flytrap, sundew, pitcher plant, etc)

Question 33

chloroplast

Answer 33

a organelle (a plastid) within a plant cell which contains pigments such as chlorophyll a and is responsible for photosynthesis

Question 34

endodermis

Answer 34

a single layer of cells forming a sheath around the vascular region in roots and some stems and leaves (pine)

Question 35

mesophyll

Answer 35

the ground tissue (parenchyma) of a leaf lying between the upper and lower epidermis and interspersed with veins; consists of cells with many chloroplasts and often with large intercellular spaces - for photosynthesis

Question 36

palisade mesophyll

Answer 36

a layer of mesophyll in the top half of the leaf with long rectangular cells oriented to take full advantage of sunlight

Question 37

spongy mesophyll

Answer 37

a layer of mesophyll in the bottom half of the leaf with loosely-arranged cells surrounded by large intercellular spaces

Question 38

chlorophyll a

Answer 38

the main photosynthetic pigment which traps light energy; absorbs light with wavelengths that peak at 430nm (violet and blue) and at 662nm (orange and red)

Question 39

chlorophyll b

Answer 39

an accessory photosynthetic pigment; absorbs light with wavelengths that peak at 453nm (blue and green) and at 660nm (orange)

Question 40

carotenoid pigments

Answer 40

a group of accessory photosynthetic pigments, including carotenes and xanthophylls

Question 41

xanthohyll

Answer 41

an accessory photosynthetic pigment; one of the carotenoid pigments which absorbs light with wavelengths that peak at 450nm (blue and green)

Question 42

carotene

Answer 42

an accessory photosynthetic pigment; one of the carotenoid pigments which absorbs light with wavelengths that peak at 440nm (violet) and 470nm (blue)