Deck 17: Structure of Plants

Question 1

The vascular tissue

A) may contain chloroplasts and undertake photosynthesis.
B) includes aerenchyma, spongy parenchyma with a network of air spaces.
C) transports sugars around the plant.
D) is composed of xylem and trachids.
E) facilitates the exchange of materials with the environment.

Answer 1

transports sugars around the plant.

Question 2

Ground meristem

A) produces the root system.
B) produces the ground tissue system.
C) cells that develop into the root cap.
D) produces secondary growth.
E) develops from protoderm.

Answer 2

produces the ground tissue system.

Question 3

Which of the following cells are dead at functional maturity?

A) Cork cells
B) Vessel elements
C) Sclerenchyma cells
D) Cork cells and vessel elements
E) Cork cells, vessel elements and sclerenchyma cells

Answer 3

Cork cells, vessel elements and sclerenchyma cells

Question 4

Xylem and phloem are referred to as

A) dermal tissue.
B) primary tissue.
C) ground tissue.
D) stem tissue.
E) vascular tissue.

Question 5

In plants, the portions of the stems between the points of leaf attachment are called

A) cladodes.
B) petioles.
C) internodes.
D) phyllodes.
E) cortex.

Question 6

In plant stems, the stele is the

A) whole of the stem of dicots.
B) central vascular cylinder in monocot stems.
C) central vascular cylinder of dicot stems.
D) parenchymal cells which form the stem of dicots.
E) cortex of monocot and dicot stems.

Question 7

Cambium

A) produces wood and bark in woody dicots.
B) is characteristic of woody monocots.
C) the prominent ring of vascular bundles in the stems of dicots.
D) adds length to stems by adding new cells behind it.
E) is a primary meristem, adding new cells laterally to increase stem girth.

Question 8

In plants, the vascular cambium

A) produces wood and bark.
B) produces secondary phloem and xylem.
C) is found mainly in monocots.
D) adds to the length of the plant.
E) produces most of the stem tissue.

Question 9

Growth rings in trees

A) occur as a result of changes in growth rates and thus xylem cell size.
B) are useful in the aging of trees in stable and erratic environments.
C) indicate where rings of phloem interspace rings of xylem.
D) indicate where vessels have become infiltrated with organic compounds.
E) are produced from ray parenchymal cells which lose their water-conducting capacity.

Question 10

The heartwood of a tree consists of

A) functional xylem.
B) collenchyma.
C) non-functional xylem.
D) phloem.
E) non-functional phloem.

Question 11

Cork cambium

A) like vascular cambium, is a permanent, continuous cylinder.
B) forms in the cortex of young stems and the secondary phloem of old stems.
C) is corky tissue which replaces the epidermis forming the thick-walled phelloderm.
D) produces phellem to the inside and phelloderm to the outside.
E) in monocots replaces vascular cambium.

Question 12

If bark is present it consists of

A) all of the tissue outside the vascular cambium in a tree trunk.
B) only primary tissue (e.g. epidermis, cortex and/or phloem) in young stems.
C) secondary phloem, cork cambium and cork in old stems.
D) phelloderm and cork cambrium.
E) All of the answers are correct.

Question 13

The edible part of a potato plant, the tuber, is a

A) corm.
B) modified secondary meristem.
C) specialised underground stem.
D) swollen root hair.
E) storage root.

Question 14

There are three major zones of development in plant roots. Starting behind the root cap these are the

A) zone of cell differentiation, pericycle and elongation zone.
B) meristematic zone, elongation zone and zone of cell differentiation.
C) elongation zone, meristematic zone and cortex.
D) meristematic zone, pericycle and elongation zone.
E) meristematic zone, zone of cell differentiation, elongation zone.

Question 15

In woody dicots root hairs are most abundant on that part of the root where

A) primary growth cells are differentiating.
B) the vascular cambium is active.
C) lateral roots are developing.
D) cell division and elongation are occurring.
E) the meristematic zone where rapid cell growth occurs.

Question 16

A cross-section of a structure that was identified as plant material was found in a thin section of rock. The plant structure was round in cross-section, with a central pith of parenchyma surrounded by metaxylem. The metaxylem was to the inside of the protoxylem and areas of primary phloem alternated with the many arches of primary xylem. The section is most likely to be of a

A) monocotyledon stem.
B) dicotyledon stem.
C) monocotyledon root.
D) either a monocotyledon or dicotyledon root.
E) dicotyledon root.

Question 17

In plants, lateral roots arise from the

A) pericycle.
B) endodermis.
C) cortex.
D) epidermis.
E) primary phloem.

Question 18

In dicot roots

A) the pericycle is the innermost layer of the cortex.
B) the endodermis is specialised cortex cells.
C) vascular cambium is usually absent.
D) the epidermis contains specialised cells impregnated with suberin to make them water-resistant.
E) there is rarely secondary growth.

Question 19

Water and minerals tend to enter plants from the soil via the apoplastic pathway. This means that they

A) move through epidermal cells.
B) bypass the Casparian strip.
C) diffuse through the endodermis.
D) actively taken up by the cells of the Casparian strip.
E) move through walls and spaces between cells of the epidermis and cortex.

Question 20

In roots

A) the Casparian strip allows the back flow of water into the root cortex.
B) the endodermis prevents the loss of sucrose from the phloem.
C) ions move by diffusion through the living cells of the stele.
D) water and ions moving through root tissue cannot switch between the apoplastic and symplastic pathways.
E) the apoplastic pathway ensures the physiological control of water uptake by plants.

Question 21

Aquatic, especially submerged, plants

A) have simple roots.
B) are highly vascularised.
C) do not need cortical aerenchyma.
D) contain large palisade cells which store water.
E) transpire heavily.

Question 22

The exodermis found in the roots of some salt-tolerant trees

A) enables the root to exclude chloride ions.
B) develops under the epidermis in the zone where secondary growth is occurring.
C) ensures that there is a zone of unsuberised cells near the root tip.
D) has an extensive surface area to enable the uptake of nutrients from the soil.
E) prevents water entering at the root tip.

Question 23

Root nodules, characteristic of legumes and wattles, contain

A) bacteria which convert organic nitrogen to gaseous nitrogen.
B) bacteria which fix gaseous nitrogen to ammonium.
C) fungi which fix gaseous nitrogen to ammonium.
D) bacteroids which secrete the enzymes to transport nitrogen into the cell.
E) fungi which convert organic nitrogen to gaseous nitrogen.

Question 24

An ectomycorrhizal association is most likely to be established between

A) a legume and a bacterium.
B) a zygomycete and a grass.
C) Rhizobium and coralloid roots.
D) Rhizobium and proteoid roots.
E) proteoid roots and bacteria.

Question 25

Dorsiventral leaves

A) are internally and externally similar on both sides.
B) tend to hang vertically.
C) are arranged to enhance illumination on one side.
D) maintain an orientation for equal illumination on both sides of the leaf.
E) are modified to enhance illumination on both sides.

Question 26

Guard cells in a leaf

A) are a protection against herbivores.
B) control the exchange of gases and loss of water.
C) are epidermal cells without chloroplasts.
D) are connected directly to the vascular system.
E) secrete oil in eucalypts.

Question 27

In a typical leaf blade

A) chloroplasts are most abundant in epidermal cells.
B) CO₂ diffuses from the stomata through the air spaces of the palisade mesophyll to the spongy mesophyll.
C) veins run parallel along the axis of the blade.
D) chloroplasts are most abundant in the palisade mesophyll.
E) the spongy mesophyll intercepts most light for photosynthesis.

Question 28

Ground tissue of the plant includes

A) parenchyma.
B) collenchyma.
C) sclerenchyma.
D) chlorenchyma.
E) All of the answers are part of plant ground tissue.

Question 29

Sclerenchyma

A) is the supporting tissue that provides strength.
B) contains secondary cell walls which are impregnated with lignin.
C) is composed of long tubular cells arranged in longitudinal bundles.
D) is composed of irregularly shaped cells, sclereids, which play a role in plant protection.
E) All of the answers are correct.

Question 30

Vascular cambrium

A) consists of a number of cell types including sieve tubes and tracheids.
B) contains two types of meristematic cells, fusiform and ray initials.
C) is a continuous multilayered cylinder of living meristem between the cortex and the pith.
D) is responsible for the production of secondary vascular tissues.
E) All of the answers are correct.

Question 31

Periclinal division is

A) cell division in the plane parallel to the stem surface.
B) cell division leading to increased stem length.
C) cell division of triploid endosperm cells to provide diploid cells.
D) division of fusiform initials to produce clusters.
E) rapid cell division at the apical meristem.

Question 32

The endodermis is

A) a layer of one or more cells thick which give rise to lateral roots.
B) important because it enables the plant to control water uptake.
C) a ring of specialised cells the walls of which are impregnated with suberin to enable the up-take up solutes.
D) located on the outside of the epidermis and the cortex.
E) the undifferentiated cells that become the secondary xylem and phloem.

Question 33

Which of the following statements is INCORRECT?

A) Periderm is a protective tissue that replaces the epidermis in older stems.
B) Cork cambium produces new cells laterally, increasing the girth of the stem.
C) In woody tissues of monocotyledons there is no vascular cambium.
D) Cork consists of closely packed dead cells, surrounded by a protective layer of water-resistant cells
E) Periderm is the tissue that forms corky tissue.

Question 34

Adventitious roots

A) are common at the nodes of dicotyledons.
B) form at the base of the stems.
C) form from the radicle of the embryo.
D) arise from the taproot.
E) are modified roots assisting clasping in climbing plants.

Question 35

Adaptation of stems to saline conditions include

A) fleshy stems with large palisade cells containing chloroplasts.
B) thin-walled cuticle covering a multilayered epidermis.
C) epidermal cells rich in chloroplasts for photosynthesis since leaves are reduced.
D) extensive aerenchyma with large gas-filled intracellular spaces.
E) All of the answers are correct.

Question 36

Monocotlyedons and dicotlyedons differ in structure. Differences include

A) leaves of monocotyledons have parallel veins.
B) scattered vascular bundles in monocotyledons.
C) absence of secondary growth in monocotyledons.
D) absence of primary roots in monocotyledons.
E) absence of adventitious roots in dicotyledons.

Question 37

The primary walls of collenchyma cells are thickened with

A) hemicellulose, cellulose, $\beta$ -glucan.
B) cellulose, protein, phospholipid.
C) pectins, cellulose, hemicellulose.
D) pectins, xylan, arabinose.
E) phospholipids, $\beta$ -glucan, galactose.

Question 38

In phloem, photosynthetic products can move both laterally and vertically. Therefore, the protoplasmic strands that link adjacent sieve tube elements are

A) actively opened and closed in response to phytochemical messages.
B) located on sieve tube plates on end walls.
C) located on sieve areas on side walls.
D) largely absent.
E) located on sieve tube plates on end walls and sieve areas on side walls.

Question 39

What does the vascular tissue of leaves arise from?

A) Branching of the stem vascular system
B) Shoot apical meristem
C) Vascular cambium
D) Epicormic buds
E) Budding originating from petioles

Question 40

How are leaves typically arranged and what mathematical relationship describes this pattern?

A) In an ordered and regular pattern, described by a Romelli sequence
B) All the options listed here are incorrect
C) In a random, sporadic pattern, described by a Fibonacci sequence
D) In an ordered and regular pattern, described by a Marconi sequence
E) In a random, sporadic pattern, described by a Spirello sequence

Question 41

Which of the following aspects of leaf morphology and anatomy are NOT directly influenced by the environment?

A) Leaf structure
B) Leaf size
C) Chloroplast structure
D) Number of petioles
E) Cuticle thickness

Question 42

While working in the field you come across a small, unknown plant. Upon closer inspection you note that it has small, scale-like leaves and a thick cuticle. From these observations, what type of habitat is this plant most likely to be found in?

A) Moist fern gully
B) Dry or arid
C) Coastal scrub
D) Alpine
E) Tundra

Question 43

Which of the following statements describes the structural adaptations of leaves in succulent plants, and the type of habitat are they adapted to?

A) Large parenchyma cells with a central vacuole that contains dissolved substances and water. This is an adaptation to a dry or arid environment.
B) Large parenchyma cells with a central vacuole that contains dissolved substances and water. This is an adaptation to a cold, sub-alpine environment.
C) Hard, needle-like leaves with thick cuticle and sunken stomata. This is an adaptation to a boreal environment.
D) Large, wide, thin leaves with low palisade mesophyll content. This is an adaptation to a cool, shaded environment.
E) Hard, wide, thick leaves with an extensive epidermis and low chlorophyll count. This is an adaptation to a sclerophyllous environment.

Question 44

Different plant tissues often have specific functions. If the roles of one tissue include being a physical barrier to pathogens, water loss prevention and protection from harmful sun's rays, what tissue would this be?

A) Mucilage
B) Bundle sheath
C) Cell membrane
D) Cell wall
E) Cuticle

Question 45

Under conditions such as high humidity, transpiration can be limiting. Under such conditions, what important role would a pore-like structure play, and what is the name of such a structure?

A) It would help maintain ion transport via pores called hydathodes.
B) It would help maintain osmotic potential via pores called ion-channels.
C) It would help maintain water movement and therefore ion transport via pores called hydrophores.
D) It would help maintain a negative membrane potential via pores called symplasts.
E) It would help maintain diffusion gradients via pores called antiports.