Lecture 7

Question 1

how does the apical meristem aid in stem growth

Answer 1

it adds cells to primary plant body, produces leaf primordia and bud primordial, protect young leaves, phytomeres

Question 2

how does the vegetative shoot apex help stem growth

Answer 2

tunica-corpus organization

Question 3

what is tunica organization

Answer 3

outermost layer of cells, divide anticlinally

Question 4

what is corpus organization

Answer 4

body of cells beneath tunica, divide periclinally

Question 5

how is the vegetative shoot apex different than the root

Answer 5

can’t be divided into zones like the root

Question 6

what happens to prevent the vegetative shoot apex from differentiating into zones

Answer 6

leaf primordia originate too quickly to distinguish nodes and internodes; elongation occurs primarily when internodes elongate

Question 7

what is the intercalary meristem

Answer 7

a meristematic region between 2 more highly differentiated regions

Question 8

what must happen before an internode can elongate

Answer 8

leaves need to finish differentiating

Question 9

what causes stem thickness

Answer 9

periclinal division, cell enlargement, (in monocots meristematic cap)

Question 10

what are the three basic organizations in the primary structure of the stem

Answer 10

vascular system is more or less continuous cylinder within ground tissue, primary vascular tissues develop as bundles separated by ground tissue, and more complex

Question 11

what type of plants have continuous organization vascular systems

Answer 11

some conifers, magnoliids, and eudicots

Question 12

what types of plants have bundle organization in their vascular system

Answer 12

eudicots

Question 13

what types of plants have complex organizations in their vascular system

Answer 13

herbaceous eudicots and monocots

Question 14

what are some of the relationships between the vascular tissues of the stem and leaf

Answer 14

procambial system of leaf is continuous with stem, bundles diverge at each node, leaf traces, leaf trace gaps

Question 15

what are leaf traces

Answer 15

extensions in stem towards leaves

Question 16

what are leaf trace gaps

Answer 16

gaps of ground tissue in vascular cylinder above leaf traces

Question 17

what does the pattern of the vascular system in a stem reflect

Answer 17

the arrangement of leaves

Question 18

what are the five different phyllotaxy of leaves

Answer 18

helical, distichous, opposite, decussate, and whorled

Question 19

what is the difference between pinnately and palmately compound leaves

Answer 19

pinnately- leaflets arise from either side of an axis in one plane; palmately- leaflets arise from the end of the petiole in one plane

Question 20

what are the two ways to distinguish leaflets from leaves

Answer 20

buds are in axils of leaves not of leaflets, leaves extend in various planes

Question 21

what are the three ways you can characterize plants by water availability

Answer 21

mesophytes, hydrophytes, and xerophytes

Question 22

what are mesophytes

Answer 22

plants that are exposed to moderate amount of water

Question 23

what are hydrophytes

Answer 23

plants that grow in water

Question 24

what are xerophytes

Answer 24

plants that have little to no water

Question 25

what are the characteristics of epidermis on a leaf

Answer 25

compactly arranged, covered with cuticle, stomata may occur on one or both sides

Question 26

what are the two arrangements the stomata may have on a leaf

Answer 26

scattered and rows

Question 27

what type of plants have scattered stomata on their leaves

Answer 27

eudicots

Question 28

what type of plants have stomata arranged in rows on their leaves

Answer 28

monocots

Question 29

what are some characteristics of the epidermis on xerophytes

Answer 29

may have more stomata, sunken stomata on lower surface of leaves, epidermal hairs

Question 30

what are some characteristics of the epidermis on mesophyll

Answer 30

ground tissue of leaf, large volume of intercellular spaces, numerous chloroplasts mesophytes

Question 31

what is the differences between C3 and C4

Answer 31

bundle-sheath cells/leaf anatomy, inter veinal distances

Question 32

what things are involved in leaf development

Answer 32

founder cells, leaf buttress, leaf primordium, intercalary growth, tips of leaf stop growing first, determinate growth

Question 33

what is leaf primordium

Answer 33

side closest to apical meristem is often flatter than the opposite side

Question 34

what is intercalary growth

Answer 34

different rates of cell division and enlargement, cell enlargement contributes most to expansion

Question 35

what are some characteristics of mangled and eudicot leaf development

Answer 35

procambium differentiates to become mid vein, major veins develop upward/outward, minor veins initiate at leaf tip

Question 36

which direction do minor veins grow

Answer 36

start growing at the edge and work their way backwards

Question 37

what are some characteristics of monocot leaf development

Answer 37

growth spreads laterally and encircles shoot apex, then growth proceeds linearly from basal meristem

Question 38

what are characteristics of sun leaves

Answer 38

smaller, thicker than shade leaves; more extensive vascular system; epidermal cell walls thicker; higher photosynthetic rates under high light

Question 39

what is leaf abscission

Answer 39

separation of leaf from stem

Question 40

what is the abscission zone

Answer 40

formed by structural and chemical changes near base of petiole (woody angiosperms)

Question 41

what are characteristics of leaf abscission

Answer 41

abscission zone, retranslocation, and leaf scar

Question 42

what is the sequence of development of the flower

Answer 42

flower parts develop in order of sepals, petals, stamens, and then carpels

Question 43

what is the sequence of physiological and structural changes of the development of the flower

Answer 43

vegetative shoot apex becomes reproductive apex; often preceded by elongation of internodes; development of lateral buds below shoot apex; apex increases mitotic activity (becomes dome shaped)

Question 44

what is homeotic mutation

Answer 44

mutations which result in the formation of the wrong floral organ in the wrong place

Question 45

what are tendrils

Answer 45

aid in support, most modified leaves, some modified stems

Question 46

what are cladophyll

Answer 46

modified stems that appear to be leaves, do not have buds in axils, (ex. asparagus and some cacti)

Question 47

what are spines

Answer 47

modified leaves

Question 48

what are thorns

Answer 48

modified branches in axils of leaves

Question 49

what are prickles

Answer 49

outgrowth from cortex and epidermis (ex. rose "thorn")

Question 50

how are leaves modified on carnivorous plants

Answer 50

leaves modified to trap insects

Question 51

what are tubers

Answer 51

modified underground stem, food storage

Question 52

what is a bulb

Answer 52

large bud of a small stem with many modified leaves attached, food storage, adventitious roots from bottom of stem

Question 53

how are corm leaves modified

Answer 53

thickened, fleshy stem tissue; thinner, smaller leaves than bulbs

Question 54

how are petiole leaves modified

Answer 54

thick and fleshy (ex. celery)

Question 55

how are succulent plant leaves modified

Answer 55

storage of water in stems or leaves