Deck 25: The Shoot: Primary Structure and Development

Question 1

A sessile leaf, by definition, lacks a ______.

A) blade.
B) stipule.
C) sheath.
D) lamina.
E) petiole.

Answer 1

E

Question 2

Which of the following is(are) NOT produced by the shoot apical meristem?

A) leaf primordia
B) a protective covering
C) bud primordia
D) phytomeres
E) cells of the primary plant body

Answer 2

B

Question 3

Which of the following statements about the Ranunculus stem is FALSE?

A) Its vascular bundles resemble those of monocots.
B) The procambium is lost at maturity.
C) Its vascular bundles are completely surrounded by sclerenchyma cells.
D) It has a vascular cambium.
E) It has closed vascular bundles.

Answer 3

D

Question 4

In the angiosperm shoot apex, the corpus and overlying tunica constitute the:

A) pith meristem.
B) peripheral meristem.
C) intercalary meristem.
D) central zone.
E) meristematic cap.

Question 5

Plants that are characterized as xerophytes:

A) are adapted to areas that are neither too wet nor too dry.
B) are adapted to dry habitats.
C) grow wholly or partly submerged.
D) usually have fewer stomata than other types of plants.
E) may lack stomata in some leaves.

Question 6

The auxin-based model of phyllotaxy states that auxin:

A) in young primordia lower the auxin concentration in neighboring cells.
B) in older primordia stimulate internode elongation.
C) causes the tunica to buckle.
D) in young primordia raises the auxin concentration in neighboring cells.
E) in the apical meristem stimulates cells to divide.

Question 7

Which of the following statements about cells of the tunica is FALSE?

A) Most divide anticlinally.
B) Some divide periclinally.
C) They form four layers in most angiosperms.
D) Daughter cells from one layer may be displaced into another layer.
E) They constitute the outermost cells of the shoot apex.

Question 8

In Arabidopsis, the protoderm originates from the:

A) L2 layer.
B) L3 layer.
C) outermost tunica layer.
D) corpus.
E) cortex.

Question 9

Which of the following statements about the Tilia stem is FALSE?

A) The pith contains parenchyma and mucilage ducts.
B) The cortex contains collenchyma and parenchyma.
C) The xylem is located outside the phloem.
D) The epidermis is a single layer of cells.
E) The vascular bundles are separated by interfascicular parenchyma.

Question 10

Extensions of vascular tissues into the leaves from the stem are called:

A) leaf traces.
B) leaf trace gaps.
C) branch traces.
D) stem bundles.
E) sympodia.

Question 11

Which of the following is NOT part of a phytomere?

A) axillary bud
B) internode
C) node
D) leaf
E) apical meristem

Question 12

A leaf having a rachis is a ______ leaf.

A) simple
B) palmately compound
C) pinnately compound
D) whorled
E) sessile

Question 13

The inhibitory field hypothesis of leaf arrangement states that existing leaf primordia:

A) preferentially develop in a whorled phyllotaxy.
B) cannot develop until sufficient space is available.
C) prevent the initiation of new primordia.
D) contain vascular tissues organized in field-like rows.
E) produce electrical fields that attract one another.

Question 14

______ has a stem with scattered vascular bundles.

A) Ranunculus
B) Sambucus
C) Zea
D) Medicago
E) Tilia

Question 15

A plant with decussate phyllotaxy has:

A) two leaves per node in the same rank.
B) two leaves per node in two opposite ranks.
C) one leaf per node, arranged in two opposite ranks.
D) one leaf per node, arranged spirally.
E) three or more leaves per node.

Question 16

Which of the following statements about the leaf epidermis is FALSE?

A) It is covered with a cuticle.
B) Its cells are loosely arranged.
C) Stomata may be sunken in depressions
D) Stomata may occur on one or both leaf surfaces.
E) Epidermal hairs may occur on one or both leaf surfaces.

Question 17

A plant with helical phyllotaxy has:

A) opposite leaves.
B) a decussate leaf arrangement.
C) one leaf per node, arranged in two opposite ranks.
D) one leaf per node, arranged spirally.
E) three or more leaves per node.

Question 18

In the Sambucus stem, phloem differentiates toward the ______ and xylem differentiates toward the ______.

A) center; outside
B) outside; outside
C) outside; center
D) center; center and outside
E) center and outside; center

Question 19

A leaf trace extends between the leaf and a:

A) sympodium.
B) stem bundle.
C) leaf trace gap.
D) stem bundle gap.
E) bud primordium.

Question 20

In most monocots, the base of the leaf is expanded into a ______.

A) blade.
B) stipule.
C) sheath.
D) lamina.
E) petiole.

Question 21

Compared with sun leaves, shade leaves:

A) have thicker-walled epidermal cells.
B) have a lower ratio of mesophyll surface area to leaf blade surface area.
C) have more extensive vascular systems.
D) are thicker.
E) are smaller.

Question 22

Which of the following events does NOT occur in a shoot apex during flower development?

A) A change from determinate to indeterminate growth
B) Elongation of the internodes
C) Early development of lateral buds below the apex
D) An increase in mitosis
E) A change in shape of the apex to broad and dome-like

Question 23

Which of the following statements about bundle-sheath extensions is FALSE?

A) They provide mechanical support for the leaf.
B) They interconnect all the bundle sheaths in a leaf.
C) They may conduct water from the xylem to the epidermis.
D) They consist of mesophyll cells.
E) They form connections between bundle sheaths and the epidermis.

Question 24

Which layer(s) of the peripheral zone of the shoot apical meristem are the founder cells?

A) L1 only
B) L2 only
C) L3 only
D) L1 and L2 only
E) L1, L2, and L3

Question 25

Which of the following events is NOT associated with leaf abscission?

A) Formation of tyloses
B) Formation of a suberized protective layer
C) Cell division
D) Enzymatic breakdown of cell walls
E) Return of reusable substances to the leaf

Question 26

A prickle is a modification of:

A) a branch.
B) a leaf.
C) the epidermis.
D) a stem.
E) a flower.

Question 27

Which of the following statements about bulliform cells is FALSE?

A) They are found in monocots.
B) They are large mesophyll cells.
C) They are arranged in longitudinal rows.
D) They become flaccid during excessive water loss.
E) They play a role in leaf folding and unfolding.

Question 28

Which of the following statements about the transition region and its formation is FALSE?

A) The transition region occurs between the root and the shoot.
B) The transition region is the region in which the vascular system changes locations.
C) Vascular transition is completed with the differentiation of the procambium in the seedling.
D) Vascular transition is initiated soon after seed germination.
E) The structure of the transition region is often very complex.

Question 29

Which of the following statements about palisade parenchyma is FALSE?

A) It is lacking in the leaves of maize and other grasses.
B) It is usually located on the lower side of the leaf.
C) It consists of columnar cells.
D) It is where most of the photosynthesis in the leaf occurs.
E) It is part of the mesophyll.

Question 30

In eudicots, the major veins develop toward the ______ and the minor veins develop toward the ______.

A) leaf base; leaf margins
B) leaf margins; leaf base
C) leaf base; leaf base
D) leaf margins; leaf margins and leaf base
E) leaf base and leaf margins; leaf base

Question 31

Unlike the midrib, the leaf blade develops from:

A) procambium.
B) the central region of the primordium.
C) founder cells.
D) marginal meristems..
E) the L1 layer of the tunica-corpus.

Question 32

In leaves, intercalary growth occurs by:

A) cell division alone throughout the petiole.
B) cell division and cell enlargement throughout the petiole.
C) cell enlargement alone throughout the blade.
D) cell division alone throughout the blade.
E) cell division and cell enlargement throughout the blade.

Question 33

Studies of Arabidopsis mutants have identified classes of ______ that affect the identity of floral organs.

A) meristematic activities
B) homeotic genes
C) hormones
D) tunica-corpus organizations
E) environmental factors

Question 34

Unlike C₃ grasses, C₄ grasses have leaves:

A) with mesophyll and bundle-sheath cells in two concentric layers.
B) with an interveinal distance of more than four cells.
C) without Kranz anatomy.
D) with a mestome sheath.
E) with small bundle-sheath cells containing small chloroplasts.

Question 35

The studies of homeotic mutations in Arabidopsis initially identified _____ classes of genes essential to normal flower development, but this model has recently been expanded to ____ gene classes.

A) 2; 3
B) 2; 4
C) 3; 4
D) 3; 5
E) 3; 6

Question 36

In grass leaves, the midvein and other large longitudinal strands arise at the _____ of the primordium and develop _____.

A) tip; downward
B) tip; both upward and downward
C) base; both upward and downward
D) base; upward
E) base; downward

Question 37

Most tendrils are modified:

A) roots.
B) stems.
C) leaves.
D) flowers.
E) buds.

Question 38

The homeotic mutation that results in "double flowers" in some rose varieties causes ______ to be converted into ______.

A) sepals; carpels
B) petals; stamens
C) stamens; carpels
D) petals; sepals
E) stamens; petals

Question 39

Unlike the leaves of eudicots, most monocot leaves:

A) undergo secondary growth.
B) have veins containing xylem and phloem.
C) have veins arranged in a branching pattern.
D) have netted venation.
E) have parallel venation.

Question 40

A spine is a modified:

A) branch.
B) leaf.
C) epidermal hair.
D) stem.
E) flower.

Question 41

The edible portion of an Irish potato is a:

A) rhizome.
B) tuber.
C) corm.
D) modified root.
E) cladophyll.

Question 42

Stems with closed vascular bundles are capable of secondary growth.

Question 43

By definition, a plant having leaflets has simple leaves.

Question 44

Pith rays are composed of parenchyma cells.

Question 45

A plant with decussate phyllotaxy has opposite leaves.

Question 46

Leaves that lack a petiole are said to be sessile.

Question 47

The initials of the corpus tunica-corpus usually divide anticlinally.

Question 48

Bud primordial give rise to lateral shoots.

Question 49

Bulliform cells are epidermal cells that occur in longitudinal rows.

Question 50

A succulent leaf is one that is specialized for:

A) growth in aqueous habitats.
B) chemical defense.
C) protection against predators.
D) water storage.
E) food storage.

Question 51

A sympodium contains a stem bundle and its associated leaf traces.

Question 52

Most eudicot leaves have netted venation.

Question 53

When you eat celery and rhubarb you are eating:

A) stems.
B) blades.
C) petioles.
D) flowers.
E) buds.

Question 54

In the Arabidopsis shoot apical meristem, the CLAVATA genes promote initial-cell function.

Question 55

Leaf blades are produced through the activity of marginal blastozones.

Question 56

A stolon is different from a rhizome in that a stolon:

A) is a leaf.
B) is a stem.
C) is a root.
D) grows aboveground.
E) grows underground.

Question 57

The auxin-based model of phyllotaxy states that young leaf promordia stimulate the production of auxin in neighboring cells.

Question 58

A bulb is different from a corm in that a bulb:

A) has thinner leaves.
B) has a larger stem.
C) has a fleshy stem
D) stores food in its leaves.
E) stores food in its stem.

Question 59

In most monocot but not eudicot stems, it is possible to distinguish cortex from pith.

Question 60

A bud is found in the axil of a leaf, not a leaflet.

Question 61

In monocot leaves, the midvein and other large veins develop at the tip of the primordium and develop downward.

Question 62

MADS box genes are a class of sequences that includes homeotic genes.

Question 63

In eudicot leaves, the minor veins are initiated at the base of the leaf and develop upward toward the tip.

Question 64

A thorn is a modified branch.

Question 65

The abscission zone consists of three layers: the separation layer, the protective layer, and the layer of cell division.

Question 66

A stolon is a modified, aboveground root.

Question 67

The current model for gene classes that affect flower development is called the ABCD model.

Question 68

In the transition region, there is a small but significant interruption between the vascular tissues of the root and the shoot.

Question 69

Sun and shade leaves can be found on the same plant.