Ch.25 | Full Test Bank – The Shoot Primary Structure And

Chapter 25: The Shoot: Primary Structure and Development

Multiple-Choice Questions

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

Which of the following is NOT part of a phytomere?

a. axillary bud

b. internode

c. node

d. leaf

e. apical meristem

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.

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.

In Arabidopsis, the protoderm originates from the:

a. L2 layer.

b. L3 layer.

c. outermost tunica layer.

d. corpus.

e. cortex.

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.

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

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.

______ has a stem with scattered vascular bundles.

a. Ranunculus

b. Sambucus

c. Zea

d. Medicago

e. Tilia

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.

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.

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.

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.

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.

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.

A sessile leaf, by definition, lacks a ______.

a. blade.

b. stipule.

c. sheath.

d. lamina.

e. petiole.

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

a. blade.

b. stipule.

c. sheath.

d. lamina.

e. petiole.

A leaf having a rachis is a ______ leaf.

a. simple

b. palmately compound

c. pinnately compound

d. whorled

e. sessile

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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

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

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.

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

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.

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

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

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

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

Most tendrils are modified:

a. roots.

b. stems.

c. leaves.

d. flowers.

e. buds.

A spine is a modified:

a. branch.

b. leaf.

c. epidermal hair.

d. stem.

e. flower.

A prickle is a modification of:

a. a branch.

b. a leaf.

c. the epidermis.

d. a stem.

e. a flower.

The edible portion of an Irish potato is a:

a. rhizome.

b. tuber.

c. corm.

d. modified root.

e. cladophyll.

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.

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.

When you eat celery and rhubarb you are eating:

a. stems.

b. blades.

c. petioles.

d. flowers.

e. buds.

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.

True-False Questions

Bud primordial give rise to lateral shoots.

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

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

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

Pith rays are composed of parenchyma cells.

Stems with closed vascular bundles are capable of secondary growth.

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

A plant with decussate phyllotaxy has opposite leaves.

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

Leaves that lack a petiole are said to be sessile.

By definition, a plant having leaflets has simple leaves.

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

Most eudicot leaves have netted venation.

Bulliform cells are epidermal cells that occur in longitudinal rows.

Leaf blades are produced through the activity of marginal blastozones.

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

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

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

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

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

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

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

A thorn is a modified branch.

A stolon is a modified, aboveground root.

When you slice an onion you are cutting through the leaves of a bud.

Essay Questions

1. Origin and Growth of the Primary Tissues of the Stem; pp. 581–582; difficult

Describe the structure and function of the central zone, the peripheral meristem, and the pith meristem of the shoot apex. What is their relationship to the tunica and corpus?

2. Origin and Growth of the Primary Tissues of the Stem; p. 582; difficult

How have mutants of Arabidopsis been used to study the establishment and regulation of size of the vegetative shoot apical meristem?

3. Primary Structure of the Stem; pp. 585–587; moderate

Compare and contrast the stem structures of Tilia, Sambucus, Medicago, Ranunculus, and Zea.

4. Relation between the Vascular Tissues of the Stem and the Leaf; p. 591; moderate

Compare and contrast the inhibitory field hypothesis, the first available space hypothesis, the biophysical force hypothesis, and the auxin-based model of leaf arrangement. Are these hypotheses mutually exclusive? Why or why not?

5. Morphology and Structure of the Leaf; p. 593; easy

Discuss some of the features that distinguish mesophytes, xerophytes, and hydrophytes.

6. Development of the Leaf; pp. 599–602; difficult

Compare and contrast the development of monocot and eudicot leaves.

7. Development of the Leaf; pp. 602-603; difficult

List some differences between sun leaves and shade leaves. In what ways are these differences adaptive?

8. Leaf Abscission; p. 604; moderate

Describe the sequence of events that culminates in leaf abscission.

9. Transition between Vascular Systems of the Root and Shoot; p. 604; moderate

Explain the anatomical necessity for a transition region in vascular plants.

10. Development of the Flower; pp. 605–607; difficult

What are homeotic genes? Give examples that illustrate the role of homeotic genes in flower development.

11. Stem and Leaf Modifications; pp. 607–612; moderate

Describe three examples of leaf modifications and three examples of stem modifications in angiosperms.