Ch 35, Ch 36

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Which of the following best describes the driving force that pushes the root tip through the soil?

elongation of cells behind the root apical meristem

The innermost layer of the root cortex is the

endodermis

The primary growth of a plant adds _____ and secondary growth adds _____. See Concept 35.2 (Page)

height ... girth

The primary growth of a plant adds _____ and secondary growth adds _____.

height ... girth -Apical meristems elongate shoots and roots through primary growth. Lateral meristems add girth to woody plants through secondary growth.

The primary growth of a plant adds __________, and secondary growth adds __________.

height, thickness

Which of the following would tend to increase transpiration?

higher stomatal density

Root apical meristems are found

in all roots.

Where is primary growth occurring in an old tree?

in young branches where leaves are forming

Root hairs are important to a plant because they _____. See Concept 35.1 (Page)

increase the surface area for absorption

Root hairs are important to a plant because they _____.

increase the surface area for absorption -Root hairs are extensions of individual epidermal cells on the root surface, which increase the absorptive surface area of the root tremendously.

Which of the following best describes the growth of most plant structures, except for flowers?

indeterminate

An axillary bud in the stem can potentially form a ________ in a variety of plants based on evolutionary adaptations.

lateral branch, thorn, and flower

Plasmodesmata can change in number, and when dilated can provide a passageway for ________.

macromolecules

Plants must always compromise between _____ and _____.

maximizing photosynthesis ... minimizing water loss

Cells where most evaporation of water in the leaf occurs

mesophyll

A student examining leaf cross sections under a microscope finds many loosely packed cells with relatively thin cell walls. The cells have numerous chloroplasts. What type of cells are they?

parenchyma

Which of the following root tissues gives rise to lateral roots?

pericycle

Which of the following would be LEAST likely to affect osmosis in plants?

receptor proteins in the membrane

Which one of the following refers to the loss of water through the stomata in a plant's leaves?

transpiration -The stomata in the leaves are entry points for the carbon dioxide necessary for photosynthesis, but they are also exit points for the evaporation of water by transpiration.

A plant cell with a ψsψs of -0.65 MPa maintains a constant volume when bathed in a solution that has a ψsψs of -0.30 MPa and is in an open container. The cell has a

ψp of +0.35 MPa.

44) Which of the following primarily enters a plant somewhere other than through the roots? A) carbon dioxide B) nitrogen C) potassium D) water

70) Plasmodesmata can change in number, and when dilated can provide a passageway for A) macromolecules such as RNA and proteins. B) ribosomes. C) chloroplasts. D) mitochondria. E) cytoskeletal components.

Answer: A

46) Which cells in a root form a protective barrier to the vascular system where all materials must move through the symplast? A) pericycle B) cortex C) epidermis D) endodermis E) exodermis

Answer: D

9) Active transport of various materials in plants at the cellular level requires all of the following except A) a proton gradient. B) ATP. C) membrane potential. D) transport proteins E) xylem membranes.

Answer: E

5) What would enhance water uptake by a plant cell? A) decreasing the Ψ of the surrounding solution B) positive pressure on the surrounding solution C) the loss of solutes from the cell D) increasing the Ψ of the cytoplasm

47) What tissue makes up most of the wood of a tree? A) primary xylem B) secondary xylem C) secondary phloem D) vascular cambium

B) secondary xylem

43) Which one of the following ions plays a critical role in the opening and closing of stomata? A) H+ B) Na+ C) K+ D) Ca+2

2) The innermost layer of the root cortex is the A) core. B) pericycle. C) endodermis. D) pith.

C Bloom's Taxonomy: Knowledge/Comprehension

68) ________ is to xylem as ________ is to phloem. A) Sclerenchyma cell; collenchyma cell B) Apical meristem; vascular cambium C) Vessel element; sieve-tube member D) Cortex; pith E) Vascular cambium; cork cambium

C) Vessel element; sieve-tube member

72) Gas exchange, which is necessary for photosynthesis, can occur most easily in which leaf tissue? A) epidermis B) palisade mesophyll C) spongy mesophyll D) vascular tissue E) bundle sheath

C) spongy mesophyll

Most of the growth of a plant body is the result of

cell elongation

Use the diagram to determine what flower structures develop under the conditions described below. Drag the terms on the left to the appropriate blanks on the right to complete the sentences.

1. Sepals develop where only A genes are active. 2. Petals develop where A and B genes are active. 3. Stamens develop where B and C genes are active. 4. Carpels develop where only C genes are active.

Bulk flow is much faster than diffusion or active transport. Peak velocities in the transport of xylem sap can range from ________ for trees with wide vessel elements.

15-45 m/hr

45) A lateral root originates in the ________. A) pericycle B) cortex C) endodermis D) epidermis

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.3

65) Land plants are composed of all of the following tissue types except A) mesodermal. B) epidermal. C) meristematic. D) vascular. E) ground tissue.

A) mesodermal

74) The symplast transports all of the following except A) sugars. B) mRNA. C) DNA. D) proteins. E) viruses.

Answer: C

52) If the guard cells and surrounding epidermal cells in a plant are deficient in potassium ions, all of the following would occur except A) photosynthesis would decrease. B) roots would take up less water. C) phloem transport rates would decrease. D) leaf temperatures would decrease. E) stomata would be closed.

Answer: D

31) What is the overall charge on the cytoplasmic side of a plant cell plasma membrane? A) positive B) negative C) neutral

52) Heartwood and sapwood consist of ________. A) periderm B) secondary xylem C) secondary phloem D) cork

B Bloom's Taxonomy: Knowledge/Comprehension Section: 35.4

The following questions are based on the drawings of root or stem cross sections shown in the figure. 37) Refer to the figure above. A monocot stem is represented by _____. A) I only B) II only C) III only D) IV only

B) II only

97) The innermost layer of the root cortex is the A) core. B) pericycle. C) endodermis. D) pith. E) vascular cambium.

C) endodermis

Xylem is indicated by the letter _____.

_____ bonds are responsible for the cohesion of water molecules.

Hydrogen

Primary growth increases the length of plant roots and shoots. Rank the following types of cells from least mature to most mature.

Least mature cells Apical meristem cells Primary meristem cells Background Image Differentiated cells Most mature cells

Which one of the following statements is true?

Monocot stems have scattered vascular tissue, whereas eudicot stems have vascular tissue arranged in a ring.

Select the best description of the significance of the meristems of plants.

Plant meristems are permanently embryonic regions within the plant body.

Which of the following parts of a plant remains on the plant even after several years of growth?

Primary xylem

Now look at Figure 1 again. Compare the trees grown from seeds collected in Ontario and Florida. When you grow both kinds of trees in Florida, how does their average tooth area compare with each other?

The leaves grown from Florida seeds have more than twice the average tooth area as the leaves grown from Ontario seeds.

To tease apart genotypic versus environmental effects on leaf development, it is useful to compare the plants collected from different locations in "common garden" experiments like these. Look at Figure 2. Compare the trees grown from seeds collected in Ontario and Florida. When you grow both kinds of trees in Rhode Island, how does their number of teeth per leaf area compare with each other?

The leaves grown from Ontario seeds have twice as many teeth as the leaves grown from Florida seeds.

Look at the bar graph of the number of teeth per unit leaf area data Going from northern to southern collection sites, what is the general trend in number of teeth in leaves of Acer rubrum?

The leaves have fewer teeth as you go from north to south.

Look at the bar graph of the average area of single tooth data Going from northern to southern collection sites, what is the general trend in tooth size in leaves of Acer rubrum?

The leaves have larger teeth as you go from north to south.

Which of the following statements about the distribution of sap throughout a plant is true?

The mechanism that explains the movement of sugars throughout a plant is called the pressure-flow hypothesis.

The scientific method is often presented as a series of linear steps that involves testing a hypothesis in a controlled experiment. How does this research compare with this common description of the scientific method?

The methods used in this paper differ from the standard description of the scientific method because the authors used comparative genetics to elucidate the evolutionary history and underlying mechanisms of genes that produce different leaf shape patterns in related species.

Which of the following statements about secondary growth is true? Select all that apply.

The oldest secondary vascular cells (xylem or phloem) are the farthest from the vascular cambium layer. The vascular cambium and cork cambium start actively dividing only after primary growth in that area of a root or shoot has stopped.

Which of the following is not a type of primary meristematic cell found in apical meristems?

Vascular cambium

_____ provides cells for secondary growth.

Vascular cambium

Which of the following is a correct statement about a difference between xylem and phloem transport? -Active transport moves xylem sap but not phloem sap. -Transpiration moves phloem sap but not xylem sap. -Xylem sap moves from sugar source to sink, but phloem sap does not. -Phloem carries water and minerals; xylem carries organic molecules. -Xylem sap moves up; phloem sap moves up or down.

Xylem sap moves up; phloem sap moves up or down.

Which of the following is a correct statement about a difference between xylem and phloem transport?

Xylem sap moves up; phloem sap moves up or down. -The direction of movement in xylem is from roots to leaves. Phloem sap is transported throughout the plant from source to sink.

The Q10 for the change in the viscosity of water is 1.2-1.3. Therefore, could the slight temperature dependence of water uptake by seeds be a reflection of the slight temperature dependence of the viscosity of water?

Yes; both water-related processes have about the same Q10.

Can you match these prefixes, suffixes, and word roots with their definitions?

around: peri- of neither gender or type: neutr- skin: cuti to bear, to carry: -fer between: inter- change, turn, move: -trop- egg: oo- (or ov-) across: trans- below: hypo- to produce: -gen-

Which of the following modified roots has a similar function as prop roots?

buttress roots

As the epidermis is pushed outward and sloughed off, it is replaced by tissues produced by the _____.

cork cambium

As the epidermis is pushed outward and sloughed off, it is replaced by tissues produced by the __________.

cork cambium

Which of the following is correctly matched with its tissue system?

cortex ... ground tissue system

Which of the following is correctly matched with its tissue system? See Concept 35.1 (Page)

cortex ... ground tissue system

Which of the following is correctly matched with its tissue system?

cortex, with ground tissue system

Movement of phloem sap from a source to a sink

depends ultimately on the activity of proton pumps.

An open beaker of pure water has a water potential (Ψ) of

0.0 (zero).

Arrange the following five events in an order that explains the mass flow of materials in the phloem. 1. Water diffuses into the sieve tubes. 2. Leaf cells produce sugar by photosynthesis. 3. Solutes are actively transported into sieve tubes. 4. Sugar is transported from cell to cell in the leaf. 5. Sugar moves down the stem.

2, 4, 3, 1, 5

How does a flaccid cell differ from a turgid cell?

A flaccid cell has lower pressure potential.

Select the correct statement about plant growth.

A plant may produce juvenile and adult leaves at the same time.

15) Which of the following would be least likely to affect osmosis in plants? A) a difference in solute concentrations B) receptor proteins in the membrane C) aquaporins D) a difference in water potential

32) A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. This living cell would be a part of which structure? A) a guard cell B) the root epidermis C) the endodermis D) the root cortex

37) Most of the water taken up by a plant is ________. A) used as a solvent B) used as a hydrogen source in photosynthesis C) lost during transpiration D) used to keep cells turgid

Which tissue(s) make(s) up the bark of the woody stem shown here?

Both secondary phloem and periderm

Which tissue(s) make(s) up the bark of the woody stem shown here?

Both secondary phloem and periderm -Bark includes all tissues external to the vascular cambium, including secondary phloem, the most recent periderm, and all the older layers of periderm. Read about the cork cambium and the production of peridermand and the layers of bark.

In roots the _____ forces water and solutes to pass through the plasma membranes of _____ cells before entering the _____.

Casparian strip ... endodermis ... xylem

Would you expect plant growth to have a Q10Q10 closer to 1 or to 3? Why?

Closer to 3, because growth requires energy (ATP) for the anabolic synthesis of macromolecules.

Some understory plants in dense tropical rain forests have very large leaves. Which of the following is the most likely selective advantage of these leaves?

Increased leaf surface area maximizes light absorption for photosynthesis under low light intensity.

Which structure determines the direction of root growth by sensing gravity?

Root cap

Which term describes an area where sugars are used or stored?

Sink

If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution with a water potential of -0.3 MPa, which of the following would be the most likely outcome?

The pressure potential of the cells would increase.

Select the correct mechanism of stomatal opening and closing.

The radial orientation of cellulose microfibrils in the cell walls of guard cells causes them to bow outward and open the stomatal pore when turgid

The apical meristem is a region of undifferentiated cells located at the tips of all roots and shoots. For instance, division of cells in the apical meristem add cells to the root, and as those cells grow, they increase the length of the root. Predict the result if the apical meristem cells from a shoot were removed and then grafted onto a mature region of a shoot. Drag the phrases on the left to the blanks on the right to complete the sentences. Not all phrases will be used.

The shoot region in which the apical meristem cells were removed will no longer be capable of growing in length. The mature region in which the apical meristem cells were grafted will form a new shoot.

What evidence supports the authors' claim that the RCO gene evolved from LMI1-type genes through gene duplication?

The similarity in amino acid sequences of the proteins produced from the RCO and LMI1-type genes shows that they are derived from a common ancestral gene.

Other than the transport of materials, what is another function that vascular tissue performs in a leaf?

The tissue functions as a skeleton that reinforces the shape of the leaf.

How would this change in the solute potential of the soil affect the water potential of the soil and the movement of water in or out of the roots?

The water potential of the soil will be lower, promoting water loss from the root system.

A plant cell is placed in distilled water. There is a net uptake of water by osmosis, causing the cell to become turgid. Select the correct statement about this setup, after the cell is fully turgid. -The pressure potentials (ΨP) of the cell and its surroundings are the same. -Because the cell contains more solutes than the distilled water that surrounds it, the solute potential (ΨS) of the cell is higher than the solute potential of distilled water. -The water potentials (Ψ) of the cell and its surroundings are the same.

The water potentials (Ψ) of the cell and its surroundings are the same.

How do cells in a meristem differ from cells in other types of plant tissue? See Concept 35.2 (Page)

They continue to divide.

How do cells in a meristem differ from cells in other types of plant tissue?

They continue to divide. -Meristem is embryonic tissue, and it retains the ability to divide.

Why is it important for scientists to understand the genetic basis for variation in leaf shape between related species of plants?

This research advances our understanding of how the diversity of life has evolved.

The following diagram depicts a woody stem in its three main growth sections. Sort each growth process to the growth section in which it occurs.

Top section: Primary growth occurs from the apical meristem. Vascular cambium first forms. Middle section: Secondary xylem and phloem form from the vascular cambium. Vascular rays are formed. Cork cells replace the epidermis. Bottom section: Bark consists of all layers exterior to the vascular cambium. Most thickening is from secondary xylem. Periderm is formed by cork and the cork cambium.

_____ provide(s) the major force for the movement of water and solutes from roots to leaves.

Transpiration

True or false? Plant growth involves both the production of new cells by mitosis and the expansion of cell volume.

True

If a plant's stomata are closed and no transpiration is occurring, which of the following predictions is accurate?

Without transpiration, less water will be absorbed from the soil

The phase change of an apical meristem from the juvenile to the mature vegetative phase is often revealed by

a change in the morphology of the leaves produced.

The phase change of an apical meristem from the juvenile to the mature vegetative phase is often revealed by

a change in the shape of the leaves produced.

This stained light micrograph shows a cross section through a plant organ from Hakea purpurea, a shrub native to some arid regions of Australia. Identify whether this is a root, stem, or leaf.

a leaf

The following diagram is of a cross section of a plant leaf. Use the diagram to answer the question. Which of the following is the main function associated with structure Y?

absorption of carbon dioxide

Transpiration in plants requires all of the following except: -evaporation of water molecules. -adhesion of water molecules to cellulose. -cohesion between water molecules. -active transport through xylem cells. -transport through tracheids.

active transport through xylem cells.

Phloem sap can flow ________.

both ways between production and storage sites

Which of the following structures cannot be formed by an axillary bud?

branch root

Which of the following cell types have unevenly thickened primary walls that support young, growing parts of the plant?

collenchyma cells

Which of the following have unevenly thickened primary walls that support young, growing parts of the plant?

collenchyma cells

The letter A indicates the _____.

cortex

The letter A indicates the _____.

epidermis

The water lost during transpiration is a side effect of the plant's exchange of gases. However, the plant derives some benefit from this water loss in the form of _____.

evaporative cooling and mineral transport

What is the function of cork?

insulation and waterproofing

When you eat Brussels sprouts, you are eating _____.

large axillary buds Submit

The root pericycle is the site where

lateral roots originate.

Mycorrhizae are _____.

mutualistic associations between plant roots and fungi

Which of the following is an adaptation that enhances the uptake of water and minerals by roots?

mycorrhizae

Which of these are symbiotic associations?

mycorrhizae

Which of the following can be used to determine a twig's age?

number of apical bud scar rings

The diffusion of free water across a selectively permeable membrane is called

osmosis

Solute potential in a cell is also called ________.

osmotic potential

The secondary mesophyll of leaves is made up of ________.

parenchyma tissue

Which of the following cells transport sugars over long distances?

sieve-tube elements

Which term describes an area where sugars are used or stored?

sink

Can you match these prefixes, suffixes, and word roots with their definitions?

skin: derm plant: -phyte small: micro- mouth, opening: stoma outside, outer: epi- large: mega- inside, inner: endo- single: mono- two: di- cell: -cyte (or cyto-)

According to the pressure flow hypothesis of phloem transport,

solute moves from a high concentration in the source to a lower concentration in the sink.

Many ornamental roses have sepals and multiple showy petals, but lack reproductive parts. Assuming that rose development follows the ABC hypothesis, which gene is most likely to be suppressed?

the C gene

The following are characteristics of plant cells but not animal cells except

the absence of mitochondria

The following are characteristics of plant cells but not animal cells except

the absence of mitochondria.

Which structure or compartment is separate from the apoplastic route?

the lumen of a sieve tube

Which structure is correctly paired with its tissue system?

tracheid - vascular tissue

Xerophytes minimize water loss by _____.

using the CAM pathway

When is the polarity of a plant established?

when the shoot-root axis is established in the embryo

Shoot elongation in a growing bud is due primarily to which of the following?

cell elongation localized in each internode

Cells with a coating that prevents evaporation of water

lower epidermis/upper epidermis

Heartwood and sapwood consist of

secondary xylem

33) Which of the following root tissues gives rise to lateral roots? A) endodermis B) phloem C) epidermis D) pericycle

D) pericycle

The cohesiveness of water molecules is due to

hydrogen bonds between water molecules

A strawberry plant mutant that fails to make stolons would suffer from

a reduction in asexual reproduction.

Which of the following describes an anatomical difference between roots and leaves?

a waxy cuticle covers leaves but is absent from roots

Surface tension, adhesion, and cohesion are properties of water that arise from the ability of water molecules to form hydrogen bonds with each other and with other polar molecules. What distinguishes surface tension, adhesion, and cohesion from one another is where the hydrogen-bonded molecules are found. The diagram below shows the air-water interface at the top of a narrow tube filled with liquid water. Space-filling models of several water molecules are shown with their O atoms in red and H atoms in white. Notice that each of the pink targets (labeled a-g) lies within a rectangle that surrounds either a pair of water molecules or a water molecule and a molecule in the wall of the tube. Label each target to indicate if the interaction between the molecules inside the rectangle contributes to surface tension (T), adhesion (A), or cohesion (C). Note that one target should be left blank because the molecules inside that rectangle are not involved in any of these interactions.

a) T b) T c) C d) no label e) C f) A g) A

Surface tension, cohesion, and adhesion play different roles in the transport of water from the roots to the leaves in the xylem. One role is to generate the force that ultimately pulls the water up through the xylem. Another role is to transmit that force uniformly throughout the xylem. A third role is to help oppose the force of gravity, which tends to pull water downward in the xylem. Drag a label to each target in the table to indicate the role that surface tension, adhesion, and cohesion play in the transport of water in the xylem. Labels may be used more than once. (Hint: The label "generates pull" belongs in only one target in the table.)

a) generates pull b) not present c) not present d) opposes gravity e) opposes gravity f) transmits pull g) transmits pull h) transmits pull

What class of genes act as developmental control genes to generate the diverse morphologies of plants and animals on Earth?

homeobox genes

Which of the following accurately describes the structure of a leaf?

stomata can occur on both sides of a leaf

Photosynthesis ceases when leaves wilt, mainly because

stomata close, preventing CO2 from entering the leaf

Photosynthesis begins to decline when leaves wilt because

stomata close, restricting CO2 entry into the leaf.

Which cells in a root form a protective barrier to the vascular system where all materials must move through the symplast?

endodermis

Which tissue acts as a filter on the water absorbed by root hairs?

endodermis

The innermost layer of the root cortex is the

endodermis.

A plant cell placed in a solution with a lower (more negative) water potential will _____.

lose water and plasmolyze

Most of the water taken up by a plant is _____.

lost during transpiration

Water potential is generally most negative in which of the following parts of a plant?

mesophyll cells of the leaf

If ΨP = 0.3 MPa and ΨS = -0.45 MPa, the resulting Ψ is ________.

-0.15 MPa

If ΨP = 0.3 MPa and ΨS = -0.45 MPa, the resulting Ψ is

-0.15 MPa.

Assuming that the NaCl is completely ionized, calculate how much it will lower the solute potential of the soil at 20°C using the solute potential equation: ѰS = -iCRT where i is the ionization constant (2 for NaCl), C is the molar concentration (in mol/L), R is the pressure constant [R = 0.00831 L • MPa/(mol • K)], and T is the temperature in Kelvin (273 + °C). How much will the solute potential of the soil be lowered at 20°C?

-0.243 MPa

The development of specific plant structures in particular locations is called pattern formation. Events in a plant's early development play an important role in establishing the plant's form. Complete the flowchart about pattern formation in plants beginning with the normal division of a plant zygote (fertilized egg). Drag the labels to their appropriate locations on the flowchart. Not all labels will be used.

1) plant zygote divides asymmetrically 2) daughter cells of different sizes 3) axial polarity 4) root end and shoot end

Chemical bonds hold together the atoms that make up a molecule. Molecules may also be attached to one another by chemical bonds. The figure shows how hydrogen bonds attach water molecules to other water molecules.

1. A water molecule consists of one oxygen atom joined to each of two hydrogen atoms by a(n) polar covalent bond, a type of bond in which the electrons do not spend equal time with the two atoms involved. 2. Because oxygen is more electronegative than hydrogen, the electrons in a water molecule spend more time closer to oxygen. 3. The unequal distribution of electrons means that each of the three atoms in a water molecule has a partial charge. This makes water a polar molecule. 4. The oxygen of a water molecule has a partial negative charge. 5. Each hydrogen in a water molecule has a partial positive charge. 6. A weak bond called a(n) hydrogen bond forms as a result of the attraction between the slightly positive hydrogen of one water molecule and the slightly negative oxygen of a nearby water molecule.

41) Water potential is generally most negative in which of the following parts of a plant? A) mesophyll cells of the leaf B) xylem vessels in leaves C) xylem vessels in roots D) cells of the root cortex

Plants grow in two very different ways. Each type of growth is accomplished by specific types of cells, in specific areas of the plant, and for specific purposes. Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Terms may be used once, more than once, or not at all.

1. Primary growth is the method by which roots and shoots are elongated in all vascular plants. 2. Secondary growth is the method by which woody plants grow in thickness. 3. Secondary growth is accomplished by two cylinders of dividing cells called lateral meristems. 4. Primary growth is accomplished by groups of undifferentiated cells at the tips of the roots and shoots called apical meristems. 5. The majority of growth in width is due to increases in the number of cells added by the vascular cambium.

Secondary growth, the increase in thickness of roots and shoots, is made possible by division of cells in the lateral meristems. Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Terms may be used once, more than once, or not at all.

1. Secondary growth produced by the cork cambium is unidirectional due to cells being added only to the outside of the cambium layer. 2. Secondary growth produced by the vascular cambium is bidirectional due to cells being added to both sides of the cambium layer. 3. The vascular cambium generates xylem cells to the inside and phloem cells to the outside. 4. The majority of cells added during secondary growth are xylem cells. 5. The tissue that is commonly referred to as "wood" in a woody plant is composed of xylem cells formed from the vascular cambium.

45) The opening of stomata is thought to involve ________. A) an increase in the solute concentration of the guard cells B) active transport of water out of the guard cells C) decreased turgor pressure in guard cells D) movement of K+ from the guard cells

51) Several tomato plants are growing in a small garden plot. If soil water potential were to drop significantly on a hot, summer afternoon, which of the following would most likely occur? A) Size of stomatal openings would decrease. B) Transpiration would increase. C) The leaves would become more turgid. D) The uptake of carbon dioxide would be enhanced.

As a youngster, you drive a nail in the trunk of a young tree that is 3 meters tall. The nail is about 1.5 meters from the ground. Fifteen years later, you return and discover that the tree has grown to a height of 30 meters. About how many meters above the ground is the nail?

1.5

1) Given that early land plants most likely share a common ancestor with green algae, the earliest land plants were most likely ________. A) nonvascular plants that grew leafless, photosynthetic shoots B) species that did not exhibit alternation of generations C) vascular plants with well-defined root systems D) plants with well-developed leaves

14) Which of following ions play the primary role in basic transport processes in plant cells? A) H+ B) Na+ C) K+ D) Ca+2

17) If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution with a water potential of -0.3 MPa, which of the following would be the most likely outcome? A) The pressure potential of the cells would increase. B) Water would move out of the cells. C) The cell walls would rupture, killing the cells. D) Solutes would move out of the cells.

19) The value for Ψ in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (Ψ = -0.23 MPa), the net water flow would ________. A) be from the tissue into the sucrose solution B) be from the sucrose solution into the tissue C) be in both directions, and the concentration of water would remain equal D) be impossible to determine from the values given here

20) In the transmembrane route for transport within plant tissue, ________. A) water and solutes move out of one cell, across the cell wall, and into the neighboring cell B) water and solutes move out of one cell, through the plasmodesmata, and into the neighboring cell C) water moves out of one cell, across the cell wall, and into the neighboring cell D) solutes move out of one cell, across the plasmodesmata, and into the neighboring cell

24) Compared to a cell with few aquaporins in its membrane, a cell containing many aquaporins will ________. A) have a faster rate of osmosis B) have a lower water potential C) have a higher water potential D) have a faster rate of active transport

28) The value for Ψ in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (Ψ = -0.23 MPa), the net water flow would ________. A) be from the tissue into the sucrose solution B) be from the sucrose solution into the tissue C) be in both directions and the concentrations would remain equal D) occur only as ATP was hydrolyzed in the tissue

39) During the nighttime, due to lack of transpiration, the water potential within the vascular cylinder ________. A) lowers due to accumulation of minerals B) increases due to accumulation of minerals C) lowers due to loss of minerals D) increases due to loss of minerals

55) In xerophytes, ________ are referred to as crypts. A) stomata recessed in cavities B) guard cells C) hairs (trichomes) D) lower epidermal cells

58) Water flows into the source end of a sieve tube because ________. A) sucrose has been actively transported into the sieve tube, making it hypertonic B) water pressure outside the sieve tube forces in water C) the companion cell of a sieve tube actively pumps in water D) sucrose has been transported out of the sieve tube by active transport

59) Which of the following supports the finding that sugar translocation in phloem is an active (energy-requiring) process? A) Sucrose occurs in higher concentrations in companion cells than in the mesophyll cells where it is produced. B) Movement of water occurs from xylem to phloem and back again. C) Strong pH differences exist between the cytoplasm of the companion cell and the mesophyll cell. D) ATPases are abundant in the plasma membranes of the mesophyll cells

61) In the pressure-flow mechanism, loading of sucrose from companion cells to sieve-tube elements takes place through ________. A) plasmodesmata B) facilitated diffusion C) sucrose-H+ symporters D) sucrose-H+ antiporters

65) Plasmodesmata can change in number, and when dilated can provide a passageway for ________. A) macromolecules B) ribosomes C) chloroplasts D) mitochondria

66) The symplastic route can transport ________. A) sugars, mRNA, and mitochondria B) mRNA, mitochondria, and proteins C) mitochondria, mRNA, and viruses D) viruses, sugars, and mRNA

7) The leaf area index is the ratio of the ________. A) upper leaf surface of a single plant divided by the surface area of the land on which the plant grows B) lower leaf surface of a single plant divided by the surface area of the land on which the plant grows C) upper leaf surface of a single plant multiplied by the surface area of the land on which the plant grows D) lower leaf surface of a single plant multiplied by the surface area of the land on which the plant grows

Ground tissue is indicated by the letter _____.

28) Which of the following can be used to determine a twig's age? A) number of apical bud scar rings B) number of leaf scars C) number and arrangement of axillary buds D) length of internodes

A Bloom's Taxonomy: Application/Analysis Section: 35.2

32) Mitotic activity by the apical meristem of a root makes which of the following more possible? A) increased delivery of water to the aboveground stem B) decreased absorption of mineral nutrients C) increased absorption of carbon dioxide. D) effective lateral growth of the stem

A Bloom's Taxonomy: Application/Analysis Section: 35.3

40) A student examining leaf cross sections under a microscope finds many loosely packed cells with relatively thin cell walls. The cells have numerous chloroplasts. What type of cells are they? A) parenchyma B) endodermis C) collenchyma D) sclerenchyma

A Bloom's Taxonomy: Application/Analysis Section: 35.3

43) The following diagram is of a cross section of a plant leaf. Use the diagram to answer the question. The main function associated with structure Y is ________. A) absorption of carbon dioxide B) retention of water C) collection of light D) release of carbon dioxide

A Bloom's Taxonomy: Application/Analysis Section: 35.3

51) If you were able to walk into an opening cut into the center of a large redwood tree, when you exited from the middle of the trunk (stem) outward, you would cross, in order, ________. A) the annual rings, new xylem, vascular cambium, phloem, and bark B) the secondary xylem, cork cambium, phloem, and periderm C) the vascular cambium, oldest xylem, and newest xylem D) the secondary xylem, secondary phloem, and vascular cambium

A Bloom's Taxonomy: Application/Analysis Section: 35.4

4) The phase change of an apical meristem from the juvenile to the mature vegetative phase is often revealed by A) a change in the morphology of the leaves produced. B) the initiation of secondary growth. C) the formation of lateral roots. D) the activation of floral meristem identity genes.

A Bloom's Taxonomy: Knowledge/Comprehension

13) Which of the following cell types retains the ability to undergo cell division? A) a parenchyma cell near the root tip B) a functional sieve tube element C) a tracheid D) a stem fiber

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.1

15) Which of the following is correctly paired with its structure and function? A) sclerenchyma—supporting cells with thick secondary walls B) ground meristem—protective coat of woody stems and roots C) guard cells—waterproof ring of cells surrounding the central stele in roots D) periderm—parenchyma cells functioning in photosynthesis in leaves

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.1

26) Which of the following cells or tissues arise from lateral meristem activity? A) secondary xylem B) leaves C) trichomes D) tubers

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.2

29) A plant that grows one year, dies back, and then grows again the following year, produces flowers, and then dies would be considered ________. A) annual B) biennial C) perennial D) not very fit

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.2

46) Of the following plants, which stem has scattered vascular bundles? A) corn B) magnolia C) chrysanthemum D) hibiscus

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.3

30) Which of the following is the correct sequence of the zones in the primary growth of a root, moving from the root cap inward? A) zone of cell division, zone of elongation, zone of differentiation B) zone of differentiation, zone of elongation, zone of cell division C) zone of elongation, zone of cell division, zone of differentiation D) zone of cell division, zone of differentiation, zone of elongation

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.3

47) The secondary mesophyll of leaves is made up of ________. A) parenchyma tissue B) collenchyma tissue C) sclerenchyma tissue D) parenchyma and collenchyma tissues

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.3

53) Additional vascular tissue produced as secondary growth in a root originates from which cells? A) vascular cambium B) apical meristem C) endodermis D) xylem

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.4

58) The phase change of an apical meristem from the juvenile to the mature vegetative phase is often revealed by ________. A) a change in the morphology of the leaves produced B) the initiation of secondary growth C) a change in the orientation of preprophase bands and cytoplasmic microtubules in lateral meristems D) the activation of floral meristem identity genes

A Bloom's Taxonomy: Knowledge/Comprehension Section: 35.5

28) Which of the following can be used to determine a twig's age? A) Number of apical bud scar rings B) Number of leaf scars C) Number and arrangement of axillary buds D) Length of internodes

A) Number of apical bud scar rings

63) Choose the option that best describes the relationship between the cell wall thickness of parenchyma cells versus sclerenchyma cells. A) The cell walls of parenchyma cells are thinner than those of sclerenchyma cells. B) The cell walls of parenchyma cells are thicker than those of schlerenchyma cells. C) The cell walls of both types of cells are roughly equal. D) The thickness of the cell walls for both types of cells is too variable for a comparison to be made.

A) The cell walls of parenchyma cells are thinner than those of sclerenchyma cells.

59) The phase change of an apical meristem from the juvenile to the mature vegetative phase is often revealed by _____. A) a change in the morphology of the leaves produced B) the initiation of secondary growth C) a change in the orientation of preprophase bands and cytoplasmic microtubules in lateral meristems D) the activation of floral meristem identity genes

A) a change in the morphology of the leaves produced

12) Which of the following cell types retains the ability to undergo cell division? A) a parenchyma cell near the root tip B) a functional sieve tube element C) a tracheid D) a stem fiber

A) a parenchyma cell near the root tip

44) The main function associated with structure Y is _____. A) absorption of carbon dioxide B) retention of water C) collection of light D) release of carbon dioxide

A) absorption of carbon dioxide

29) A plant that grows one year, dies back, and then grows again the following year, produces flowers and then dies would be considered _____. A) annual B) biennial C) perennial D) not very fit

A) annual

60) One major advantage of using Arabidopsis thaliana as a model system for studies of plant form and function is its A) fast generation time. B) exceptionally large genome. C) large seeds. D) high tolerance to stress. E) high mutation rate.

A) fast generation time.

A) increased delivery of water to the aboveground stem

41) A student examining leaf cross sections under a microscope finds many loosely packed cells with relatively thin cell walls. The cells have numerous chloroplasts. What type of cells are they? A) parenchyma B) endodermis C) collenchyma D) sclerenchyma

A) parenchyma

76) A cell that is most likely to retain the ability to divide, perform metabolic functions, and store photosynthate would be a A) parenchyma cell in a leaf. B) vessel element in the vascular system. C) endodermal cell in a root. D) bark cell. E) fiber cell.

A) parenchyma cell in a leaf.

85) A person working with plants may reduce the inhibition of apical dominance by auxin via which of the following? A) pruning shoot tips B) deep watering of the roots C) fertilizing D) treating the plants with auxins E) feeding the plants nutrients

A) pruning shoot tips

15) Which of the following is correctly paired with its structure and function? A) sclerenchyma — supporting cells with thick secondary walls B) ground meristem — protective coat of woody stems and roots C) guard cells — waterproof ring of cells surrounding the central stele in roots D) periderm — parenchyma cells functioning in photosynthesis in leaves

A) sclerenchyma — supporting cells with thick secondary walls

26) Which of the following cells or tissues arise from lateral meristem activity? A) secondary xylem B) leaves C) trichomes D) tubers

A) secondary xylem

90) A mutation allows only A gene activity in a developing flower. Which flower part(s) will develop in this plant? A) sepals B) petals C) stamens D) carpels E) both sepals and petals

A) sepals

10) The main source of water necessary for photosynthesis to occur in the leaf mesophyll is _____. A) soil via the xylem B) soil via the phloem C) the atmosphere through the cuticle and stomata D) all of the listed responses

A) soil via xylem

49) If you were able to walk into an opening cut into the center of a large redwood tree, when you exited from the middle of the trunk (stem) outward, you would cross, in order, _____. A) the annual rings, new xylem, vascular cambium, phloem, and bark B) the secondary xylem, cork cambium, phloem, and periderm C) the vascular cambium, oldest xylem, and newest xylem D) the secondary xylem, secondary phloem, and vascular cambium

A) the annual rings, new xylem, vascular cambium, phloem, and bark

67) Which cells are no longer capable of carrying out the process of DNA transcription? A) tracheids B) mature mesophyll cells C) companion cells D) meristematic cells E) glandular cells

A) tracheids

52) Additional vascular tissue produced as secondary growth in a root originates from which cells? A) vascular cambium B) apical meristem C) endodermis D) xylem

A) vascular cambium

11) Given that early land plants most likely share a common ancestor with green algae, the earliest land plants were most likely A) nonvascular plants that grew leafless photosynthetic shoots above the shallow fresh water in which they lived. B) species that did not exhibit alternation of generations. C) vascular plants with well-defined root systems. D) plants with well-developed leaves. E) species with a well-developed, thick cuticle.

Answer: A

A) zone of cell division, zone of elongation, zone of differentiation

Besides temperature, what other independent variable could you alter to test whether radish seed swelling is essentially a physical process or a chemical process?

Add a metabolic poison to the water to block any active metabolism and see if the results are the same as without the poison.

In addition to transporting sugar, the phloem also _____. a) transmits electrical signals b) transports viral RNA throughout the plant c) transports plant RNA throughout the plant d) transports proteins throughout the plant e) All of the above

All of the above -The phloem and symplasm are dynamic parts of the plant, with many important functions.

16) The value for Ψ in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (Ψ = -0.23 MPa), the net water flow would A) be from the tissue into the sucrose solution. B) be from the sucrose solution into the tissue. C) be in both directions and the concentrations would remain equal. D) occur only as ATP was hydrolyzed in the tissue. E) be impossible to determine from the values given here.

Answer: A

Plants and animals respond differently to the environment. Which statement most accurately compares the responses of plants and animals to changes in their environment?

Animals tend to respond to changes in their environment by movement; plants tend to respond to changes in their environment by growth.

17) Compared to a cell with few aquaporins in its membrane, a cell containing many aquaporins will A) have a faster rate of osmosis. B) have a lower water potential. C) have a higher water potential. D) have a faster rate of active transport. E) be flaccid.

Answer: A

2) The ancestors of land plants were aquatic algae. Which of the following is not an evolutionary adaptation to life on land? A) C₃ photosynthesis B) a waxy cuticle C) root hairs D) xylem and phloem E) guard cells

Answer: A

31) One would expect to find the highest density of aquaporins in which of the following? A) the plasma membrane of guard cells B) the pits of a tracheid C) the plasma membrane of parenchyma cells in a ripe fruit D) the plasma membrane of a mature mesophyll cell in a leaf E) the membrane lining plasmodesmata

Answer: A

32) If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution with a water potential of -0.3 MPa, which of the following would be the most likely outcome? A) The pressure potential of the cells would increase. B) Water would move out of the cells. C) The cell walls would rupture, killing the cells. D) Solutes would move out of the cells. E) The osmotic pressure of the cells would decrease.

Answer: A

36) Water potential is generally most negative in which of the following parts of a plant? A) mesophyll cells of the leaf B) xylem vessels in leaves C) xylem vessels in roots D) cells of the root cortex E) root hairs

Answer: A

48) All of the following normally enter the plant through the roots except A) carbon dioxide. B) nitrogen. C) potassium. D) water. E) calcium.

Answer: A

53) The opening of stomata is thought to involve A) an increase in the solute concentration of the guard cells. B) a decrease in the solute concentration of the stoma. C) active transport of water out of the guard cells. D) decreased turgor pressure in guard cells. E) movement of K+ from the guard cells.

Answer: A

56) All of the following are adaptations that help reduce water loss from a plant except A) transpiration. B) sunken stomata. C) C4 photosynthesis. D) small, thick leaves. E) crassulacean acid metabolism.

Answer: A

57) Which of the following best explains why very few CAM plants are tall? A) They have difficulty moving water and minerals to the top of the plant during the day. B) They would be unable to supply sufficient sucrose for active transport of minerals into the roots during the day or night. C) Transpiration occurs only at night, and this would cause a highly negative Ψ in the roots of a tall plant during the day. D) Since the stomata are closed in the leaves, the Casparian strip is closed in the endodermis of the root. E) With the stomata open at night, the transpiration rate would limit plant height.

Answer: A

59) A primary result for stomatal closure on a hot, dry day would be A) release of K+ ions to the apoplast and subsidiary cells. B) displacement of Ca++ ions from the thick inner walls of the guard cells. C) disassembly of the microfibrils in the cell walls of the subsidiary cells. D) upregulation of aquaporin synthesis. E) downregulation of extension proteins.

Answer: A

67) According to the pressure flow hypothesis of phloem transport, A) solute moves from a high concentration in the source to a lower concentration in the sink. B) water is actively transported into the source region of the phloem to create the turgor pressure needed. C) the combination of a high turgor pressure in the source and transpiration water loss from the sink moves solutes through phloem conduits. D) the formation of starch from sugar in the sink increases the osmotic concentration. E) the pressure in the phloem of a root is normally greater than the pressure in the phloem of a leaf.

Answer: A

73) Several tomato plants are growing in a small garden plot. If soil water potential were to drop significantly on a hot summer afternoon, which of the following would most likely occur? A) Stomatal apertures would decrease. B) Transpiration would increase. C) The leaves would become more turgid. D) The uptake of CO2 would be enhanced. E) The proton gradient would dissipate.

Answer: A

75) Which of the following is an adaptation that enhances the uptake of water and minerals by roots? A) mycorrhizae B) cavitation C) active uptake by vessel elements D) rhythmic contractions by cortical cells E) pumping through plasmodesmata

Answer: A

8) Active transport involves all of the following except the A) diffusion of solute through the lipid bilayer of a membrane. B) pumping of solutes across the membrane. C) hydrolysis of ATP. D) transport of solute against a concentration gradient. E) specific transport protein in the membrane.

Answer: A

81) Compared with a cell with few aquaporins in its membrane, a cell containing many aquaporins will A) have a faster rate of osmosis. B) have a lower water potential. C) have a higher water potential. D) have a faster rate of active transport. E) accumulate water by active transport.

Answer: A

The following photo shows a strawberry leaf displaying guttation. Answer the following question regarding guttation. 71) What is the main cause of guttation in plants? A) root pressure B) transpiration C) pressure flow in phloem D) plant injury E) condensation of atmospheric water

Answer: A

20) Which of the following would likely not contribute to the surface area available for water absorption from the soil by a plant root system? A) root hairs B) endodermis C) mycorrhizae D) fungi associated with the roots E) fibrous arrangement of the roots

Answer: B

25) What is the role of proton pumps in root hair cells? A) establish ATP gradients B) maintain the H+ gradient C) pressurize xylem transport D) eliminate excess electrons E) assist in active uptake of water molecules

Answer: B

30) One is most likely to see guttation in small plants when the A) transpiration rates are high. B) root pressure exceeds transpiration pull. C) preceding evening was hot, windy, and dry. D) water potential in the stele of the root is high. E) roots are not absorbing minerals from the soil.

Answer: B

35) In which plant cell or tissue would the pressure component of water potential most often be negative? A) leaf mesophyll cell B) stem xylem C) stem phloem D) root cortex cell E) root epidermis

Answer: B

4) A plant developed a mineral deficiency after being treated with a fungicide. What is the most probable cause of the deficiency? A) Mineral receptor proteins in the plant membrane were not functioning. B) Mycorrhizal fungi were killed. C) Active transport of minerals was inhibited. D) The genes for the synthesis of transport proteins were destroyed. E) Proton pumps reversed the membrane potential.

Answer: B

41) Active transport would be least important in the normal functioning of which of the following plant tissue types? A) leaf transfer cells B) stem tracheary elements C) root endodermal cells D) leaf mesophyll cells E) root sieve-tube elements

Answer: B

44) Water rises in plants primarily by cohesion-tension. Which of the following is not true about the cohesion-tension model? A) Water loss (transpiration) is the driving force for water movement. B) The "tension" of this model represents the excitability of the xylem cells. C) Cohesion represents the tendency for water molecules to stick together by hydrogen bonds. D) The physical forces in the capillary-sized xylem cells make it easier to overcome gravity. E) The water potential of the air is more negative than the xylem.

Answer: B

51) Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree? A) cool, dry day B) warm, dry day C) warm, humid day D) cool, humid day E) very hot, dry, windy day

Answer: B

54) Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant? A) subjecting the leaves of the plant to a partial vacuum B) increasing the level of carbon dioxide around the plant C) putting the plant in drier soil D) decreasing the relative humidity around the plant E) injecting potassium ions into the guard cells of the plant

Answer: B

6) Which structure or compartment is not part of the plant's apoplast? A) the lumen of a xylem vessel B) the lumen of a sieve tube C) the cell wall of a mesophyll cell D) the cell wall of a transfer cell E) the cell wall of a root hair

Answer: B

60) What is the driving force for the movement of solutes in the phloem of plants? A) gravity B) a difference in water potential (Ψ) between the source and the sink C) root pressure D) transpiration of water through the stomata E) adhesion of water to phloem sieve tubes

Answer: B

62) Which of the following is a correct statement about sugar movement in phloem? A) Diffusion can account for the observed rates of transport. B) Movement can occur both upward and downward in the plant. C) Sugar is translocated from sinks to sources. D) Only phloem cells with nuclei can perform sugar movement. E) Sugar transport does not require energy.

Answer: B

63) Phloem transport is described as being from source to sink. Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring? Phloem transports ________ from the ________ source to the ________ sink. A) amino acids; root; mycorrhizae B) sugars; leaf; apical meristem C) nucleic acids; flower; root D) proteins; root; leaf E) sugars; stem; root

Answer: B

65) Water flows into the source end of a sieve tube because A) sucrose has diffused into the sieve tube, making it hypertonic. B) sucrose has been actively transported into the sieve tube, making it hypertonic. C) water pressure outside the sieve tube forces in water. D) the companion cell of a sieve tube actively pumps in water. E) sucrose has been transported out of the sieve tube by active transport.

Answer: B

66) Which one of the following statements about transport of nutrients in phloem is false? A) Solute particles can be actively transported into phloem at the source. B) Companion cells control the rate and direction of movement of phloem sap. C) Differences in osmotic concentration at the source and sink cause a hydrostatic pressure gradient to be formed. D) A sink is that part of the plant where a particular solute is consumed or stored. E) A sink may be located anywhere in the plant.

Answer: B

76) Which structure or compartment is part of the symplast? A) the interior of a vessel element B) the interior of a sieve tube C) the cell wall of a mesophyll cell D) an extracellular air space E) the cell wall of a root hair

Answer: B

77) Movement of phloem sap from a source to a sink A) occurs through the apoplast of sieve-tube elements. B) depends ultimately on the activity of proton pumps. C) depends on tension, or negative pressure potential. D) depends on pumping water into sieve tubes at the source. E) results mainly from diffusion.

Answer: B

15) If ΨP = 0.3 MPa and ΨS = -0.45 MPa, the resulting Ψ is A) +0.75 MPa. B) -0.75 MPa. C) -0.15 MPa. D) +0.15 MPa. E) -0.42 MPa.

Answer: C

21) Root hairs are most important to a plant because they A) anchor a plant in the soil. B) store starches. C) increase the surface area for absorption. D) provide a habitat for nitrogen-fixing bacteria. E) contain xylem tissue.

Answer: C

23) All of the following involve active transport across membranes except A) the movement of mineral nutrients from the apoplast to the symplast. B) the movement of sugar from mesophyll cells into sieve-tube elements. C) the movement of sugar from one sieve-tube element to the next. D) the movement of K+ across guard cell membranes during stomatal opening. E) the movement of mineral nutrients into cells of the root cortex.

Answer: C

24) Which of the following statements about xylem is incorrect? A) It conducts material from root tips to leaves. B) The conducting cells are part of the apoplast. C) It transports mainly sugars and amino acids. D) It typically has a lower water potential than is found in soil. E) No energy input is required for transport.

Answer: C

27) Which of the following is not an important component of the long-distance transport process in plants? A) the cohesion of water molecules B) a negative water potential C) the root parenchyma D) the active transport of solutes E) bulk flow from source to sink

Answer: C

33) What drives the flow of water through the xylem? A) passive transport by the endodermis B) the number of companion cells in the phloem C) the evaporation of water from the leaves D) active transport by sieve-tube elements E) active transport by tracheid and vessel elements

Answer: C

34) What is the main force by which most of the water within xylem vessels moves toward the top of a tree? A) active transport of ions into the stele B) atmospheric pressure on roots C) evaporation of water through stoma D) the force of root pressure E) osmosis in the root

Answer: C

38) Which of the following is responsible for the cohesion of water molecules? A) hydrogen bonds between the oxygen atoms of a water molecule and cellulose in a vessel cell B) covalent bonds between the hydrogen atoms of two adjacent water molecules C) hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule D) covalent bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule E) low concentrations of charged solutes in the fluid

Answer: C

45) Assume that a particular chemical interferes with the establishment and maintenance of proton gradients across the membranes of plant cells. All of the following processes would be directly affected by this chemical except A) photosynthesis. B) phloem loading. C) xylem transport. D) cellular respiration. E) stomatal opening.

Answer: C

64) Arrange the following five events in an order that explains the mass flow of materials in the phloem. 1. Water diffuses into the sieve tubes. 2. Leaf cells produce sugar by photosynthesis. 3. Solutes are actively transported into sieve tubes. 4. Sugar is transported from cell to cell in the leaf. 5. Sugar moves down the stem. A) 2, 1, 4, 3, 5 B) 1, 2, 3, 4, 5 C) 2, 4, 3, 1, 5 D) 4, 2, 1, 3, 5 E) 2, 4, 1, 3, 5

Answer: C

69) Long-distance electrical signaling in the phloem has been shown to elicit a change in all of the following except A) rapid leaf movement. B) gene transcription. C) a switch from C4 to C3 photosynthesis. D) gene transcription. E) phloem unloading.

Answer: C

7) Which of the following would be least likely to affect osmosis in plants? A) proton pumps in the membrane B) a difference in solute concentrations C) receptor proteins in the membrane D) aquaporins E) a difference in water potential

Answer: C

72) A fellow student brought in a leaf to be examined. The leaf was dark green, thin, had stoma on the lower surface only, and had a total surface area of 10 square meters. Where is the most likely environment where this leaf was growing? A) a dry, sandy region B) a large, still pond C) a tropical rain forest D) an oasis within a grassland E) the floor of a deciduous forest

Answer: C

78) Photosynthesis ceases when leaves wilt, mainly because A) the chlorophyll in wilting leaves is degraded. B) flaccid mesophyll cells are incapable of photosynthesis. C) stomata close, preventing CO₂ from entering the leaf. D) photolysis, the water-splitting step of photosynthesis, cannot occur when there is a water deficiency. E) accumulation of CO₂ in the leaf inhibits enzymes.

Answer: C

80) A plant cell with a ΨS of -0.65 MPa maintains a constant volume when bathed in a solution that has a ΨS of -0.30 MPa and is in an open container. The cell has a A) ΨP of +0.65 MPa. B) Ψ of -0.65 MPa. C) ΨP of +0.35 MPa. D) ΨP of +0.30 MPa. E) Ψ of 0 MPa.

Answer: C

1) All of the following are plant adaptations to life on land except A) tracheids and vessels. B) root hairs. C) cuticle. D) the Calvin cycle of photosynthesis. E) collenchyma.

Answer: D

10) Which of the following is not a function of the plasma membrane proton pump? A) hydrolyzes ATP B) produces a proton gradient C) generates a membrane potential D) equalizes the charge on each side of a membrane E) stores potential energy on one side of a membrane

Answer: D

18) Some botanists argue that the entire plant should be considered as a single unit rather than a composite of many individual cells. Which of the following cellular structures cannot be used to support this view? A) cell wall B) cell membrane C) cytosol D) tonoplast E) symplast

Answer: D

19) Which of the following statements is false about bulk flow? A) It is driven primarily by pressure potential. B) It is more effective than diffusion over distances greater than 100 μm. C) It depends on a difference in pressure potential at the source and sink. D) It depends on the force of gravity on a column of water. E) It may be the result of either positive or negative pressure potential.

Answer: D

22) A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. This living cell would be a part of which structure? A) the Casparian strip B) a guard cell C) the root epidermis D) the endodermis E) the root cortex

Answer: D

26) In plant roots, the Casparian strip is correctly described by which of the following? A) It aids in the uptake of nutrients. B) It provides energy for the active transport of minerals into the stele from the cortex. C) It ensures that all minerals are absorbed from the soil in equal amounts. D) It ensures that all water and dissolved substances must pass through a cell membrane before entering the stele. E) It provides increased surface area for the absorption of mineral nutrients.

Answer: D

29) The following factors may sometimes play a role in the movement of sap through xylem. Which one depends on the direct expenditure of ATP by the plant? A) capillarity of water within the xylem B) evaporation of water from leaves C) cohesion among water molecules D) concentration of ions in the symplast E) bulk flow of water in the root apoplast

Answer: D

3) Most angiosperms have alternate phyllotaxy. What allows each leaf to get the maximum exposure to light and reduces shading of lower leaves? A) a leaf area index above 8 B) self-pruning C) one leaf only per node D) leaf emergence at an angle of 137.5°F from the site of previous leaves E) a leaf area index above 8 and leaf emergence at an angle of 137.5°F from the site of previous leaves

Answer: D

39) Transpiration in plants requires all of the following except A) adhesion of water molecules to cellulose. B) cohesion between water molecules. C) evaporation of water molecules. D) active transport through xylem cells. E) transport through tracheids.

Answer: D

68) Plants do not have a circulatory system like that of some animals. If a water molecule did "circulate" (that is, go from one point in a plant to another and back in the same day), it would require the activity of A) only the xylem. B) only the phloem. C) only the endodermis. D) both the xylem and the endodermis. E) both the xylem and the phloem.

Answer: E

42) Which of the following statements is false concerning the xylem? A) Xylem tracheids and vessels fulfill their vital function only after their death. B) The cell walls of the tracheids are greatly strengthened with cellulose fibrils forming thickened rings or spirals. C) Water molecules are transpired from the cells of the leaves, and replaced by water molecules in the xylem pulled up from the roots due to the cohesion of water molecules. D) Movement of materials is by mass flow; solutes in xylary sap move due to a positive turgor pressure gradient from source to sink. E) In the morning, sap in the xylem begins to move first in the twigs of the upper portion of the tree, and later in the lower trunk.

Answer: D

43) Xylem vessels, found in angiosperms, have a much greater internal diameter than tracheids, the only xylem-conducting cells found in gymnosperms. The tallest living trees, redwoods, are gymnosperms. Which of the following is an advantage of tracheids over vessels for long-distance transport to great heights? A) Adhesive forces are proportionally greater in narrower cylinders than in wider cylinders. B) The smaller the diameter of the xylem, the more likely cavitation will occur. C) Cohesive forces are greater in narrow tubes than in wide tubes of the same height. D) Adhesive forces are proportionally greater in narrower cylinders than in wider cylinders, and cohesive forces are greater in narrow tubes than in wide tubes of the same height. E) Adhesive forces are proportionally greater in narrower cylinders than in wider cylinders, and the smaller the diameter of the xylem, the more likely cavitation will occur.

Answer: D

49) Photosynthesis begins to decline when leaves wilt because A) chloroplasts within wilted leaves are incapable of photosynthesis. B) CO2 accumulates in the leaves and inhibits the enzymes needed for photosynthesis. C) there is insufficient water for photolysis during the light reactions. D) stomata close, restricting CO₂ entry into the leaf. E) wilted leaves cannot absorb the red and blue wavelengths of light.

Answer: D

55) Guard cells are the only cells in the epidermis that contain chloroplasts and can undergo photosynthesis. This is important because A) chloroplasts sense when light is available so that guard cells will open. B) photosynthesis provides the energy necessary for contractile proteins to flex and open the guard cells. C) guard cells will produce the O₂ necessary to power active transport. D) ATP is required to power proton pumps in the guard cell membranes. E) chloroplasts sense when light is available so that guard cells will open and guard cells will produce the O₂ necessary to power active transport.

Answer: D

61) Phloem transport of sucrose is often described as going from source to sink. Which of the following would not normally function as a sink? A) growing leaf B) growing root C) storage organ in summer D) mature leaf E) shoot tip

Answer: D

82) Which of the following would tend to increase transpiration? A) a rainstorm B) sunken stomata C) a thicker cuticle D) higher stomatal density E) spiny leaves

Answer: D

12) The movement of water across biological membranes can best be predicted by A) negative charges in the cell wall. B) prevailing weather conditions. C) aquaporins. D) level of active transport. E) water potential.

Answer: E

13) An open beaker of pure water has a water potential (Ψ) of A) -0.23 MPa. B) +0.23 MPa. C) +0.07 MPa. D) -0.0000001 MPa. E) 0.0 (zero).

Answer: E

14) All of the following have an effect on water potential (Ψ) in plants except A) physical pressure. B) water-attracting matrices. C) dissolved solutes. D) osmosis. E) DNA structure.

Answer: E

28) Pine seedlings grown in sterile potting soil grow much slower than seedlings grown in soil from the area where the seeds were collected. This is most likely because A) the sterilization process kills the root hairs as they emerge from the seedling. B) the normal symbiotic fungi are not present in the sterilized soil. C) sterilization removes essential nutrients from the soil. D) water and mineral uptake is faster when mycorrhizae are present. E) B and D.

Answer: E

37) Which of the following has the lowest (most negative) water potential? A) root cortical cells B) root xylem C) trunk xylem D) leaf cell walls E) leaf air spaces

Answer: E

40) Which of the following statements about transport in plants is false? A) Weak bonding between water molecules and the walls of xylem vessels or tracheids helps support the columns of water in the xylem. B) Hydrogen bonding between water molecules, which results in the high cohesion of the water, is essential for the rise of water in tall trees. C) Although some angiosperm plants develop considerable root pressure, this is not sufficient to raise water to the tops of tall trees. D) Most plant physiologists now agree that the pull from the top of the plant resulting from transpiration is sufficient, when combined with the cohesion of water, to explain the rise of water in the xylem in even the tallest trees. E) Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water in tall pine trees without transpiration pull.

Answer: E

47) Guard cells do which of the following? A) protect the endodermis B) accumulate K+ and close the stomata C) contain chloroplasts that import K+ directly into the cells D) guard against mineral loss through the stomata E) help balance the photosynthesis-transpiration compromise

Answer: E

5) If you were to prune the shoot tips of a plant, what would be the effect on the plant and the leaf area index? A) bushier plants; lower leaf area index B) tall plants; lower leaf area index C) tall plants; higher leaf area index D) short plants; lower leaf area index E) bushier plants; higher leaf area indexes

Answer: E

50) The water lost during transpiration is a side effect of the plant's exchange of gases. However, the plant derives some benefit from this water loss in the form of A) evaporative cooling. B) mineral transport. C) increased turgor. D) increased growth, E) only evaporative cooling and mineral transport.

Answer: E

58) As a biologist, it is your job to look for plants that have evolved structures with a selective advantage in dry, hot conditions. Which of the following adaptations would be least likely to meet your objective? A) CAM plants that grow rapidly B) small, thick leaves with stomata on the lower surface C) a thick cuticle on fleshy leaves D) large, fleshy stems with the ability to carry out photosynthesis E) plants that do not produce abscisic acid and have a short, thick taproot

Answer: E

79) What would enhance water uptake by a plant cell? A) decreasing the Ψ of the surrounding solution B) increasing the pressure exerted by the cell wall C) the loss of solutes from the cell D) increasing the Ψ of the cytoplasm E) positive pressure on the surrounding solution

Answer: E

Based on the data, what is the relationship between temperature and water uptake by the radish seeds?

As temperature increases, % increase in mass goes up.

Based on the data presented in the paper, evaluate the following statements about these three genes: LMI1 in Arabidopsis thaliana (AtLMI1) LMI1 in Cardamine hirsuta (ChLMI1) RCO in C. hirsuta Which of the following statements are true? Select all that apply.

AtLMI1 and ChLMI1 are orthologous genes. ChLMI1 and RCO are paralogous genes.

10) The apoplast in plant tissues consists of ________. A) cell walls, extracellular spaces, and plasmodesmata B) cell walls, extracellular spaces, and vessel elements C) vessel elements, plasmodesmata, and extracellular spaces D) cell walls, plasma membrane, and cytosol

12) The physical property that predicts the direction of water flow is referred as ________. A) potassium pump B) water potential C) osmotic potential D) sodium pump

18) Solute potential in a cell is also called ________. A) water potential B) osmotic potential C) potential gradient D) pressure potential

2) A fellow student brought in a leaf to be examined. The leaf was dark green, thin, had stoma on the lower surface only, and had a total surface area of ten square meters. Where is the most likely environment where this leaf was growing? A) a large, still pond B) a tropical rain forest C) an oasis within a grassland D) the floor of a deciduous forest

2) Which structure or compartment is part of the symplast? A) the interior of a vessel element B) the interior of a sieve tube C) the cell wall of a mesophyll cell D) an extracellular air space

22) How does a flaccid cell differ from a turgid cell? A) A flaccid cell has higher pressure potential. B) A flaccid cell has lower pressure potential. C) A flaccid cell has higher solute potential. D) A flaccid cell has lower solute potential.

25) If you place flaccid plant cells in pure water, water ________ into cell because it has ________. A) does not enter the cell; solutes and low water potential B) enter the cell; solutes and low water potential C) enter the cell; solutes and high water potential D) does not enter the cell; solutes and high water potential

3) Movement of phloem sap from a source to a sink A) occurs through the apoplast of sieve-tube elements. B) depends ultimately on the activity of proton pumps. C) depends on tension, or negative pressure potential. D) results mainly from diffusion.

30) Which of the following contribute to the surface area available for water absorption from the soil by a plant root system? I) root hairs II) endodermis III) mycorrhizae IV) fibrous arrangement of the roots A) II and III B) I, III, and IV C) I, II, and IV D) I, II, III, and IV

33) Bulk flow is much faster than diffusion or active transport. Peak velocities in the transport of xylem sap can range from ________ for trees with wide vessel elements. A) 10-20 m/hr B) 15-45 m/hr C) 5-10 m/hr D) >50 m/hr

36) One is most likely to see guttation in small plants when the ________. A) transpiration rates are high B) root pressure exceeds transpiration pull C) preceding evening was hot, windy, and dry D) roots are not absorbing minerals from the soil

40) What is the main force by which most of the water within xylem vessels moves toward the top of a tree? A) active transport of ions into the stele B) evaporation of water through stoma C) the force of root pressure D) osmosis in the root

47) Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of an oak tree? A) a cool, dry day B) a very hot, dry, windy day C) a warm, humid day D) a cool, humid day

5) A plant developed a mineral deficiency after being treated with a fungicide. What is the most probable cause of the deficiency? A) Mineral receptor proteins in the plant membrane were not functioning. B) Mycorrhizal fungi were killed. C) Active transport of minerals was inhibited. D) The genes for the synthesis of transport proteins were destroyed.

50) Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant? A) subjecting the leaves of the plant to a partial vacuum B) increasing the level of carbon dioxide around the plant C) putting the plant in drier soil D) decreasing the relative humidity around the plant

52) What is the advantage of having small, needlelike leaves? A) increased transpiration rate B) decreased transpiration rate C) increased efficiency of light capture D) decreased efficiency of light capture

54) Plants adapted to arid environments are referred to as ________. A) mesophytes B) xerophytes C) psilophytes D) halophytes

57) Arrange the following five events in an order that explains the mass flow of materials in the phloem. 1. Water diffuses into the sieve tubes. 2. Leaf cells produce sugar by photosynthesis. 3. Solutes are actively transported into sieve tubes. 4. Sugar is transported from cell to cell in the leaf. 5. Sugar moves down the stem. A) 1, 2, 3, 4, 5 B) 2, 4, 3, 1, 5 C) 4, 2, 1, 3, 5 D) 2, 4, 1, 3, 5

9) Which structure or compartment is separate from the apoplastic route? A) the lumen of a xylem vessel B) the lumen of a sieve tube C) the cell wall of a mesophyll cell D) the cell wall of a root hair

Predict what the cross section of a four-year-old tree trunk would look like if there were drought conditions for the first two years of the tree's life and wet conditions for the most recent two years.

5) Suppose a flower had normal expression of genes A and C and expression of gene B in all four whorls. Based on the ABC hypothesis, what would be the structure of that flower, starting at the outermost whorl? A) carpel-petal-petal-carpel B) petal-petal-stamen-stamen C) sepal-carpel-carpel-sepal D) sepal-sepal-carpel-carpel

B Bloom's Taxonomy: Application/Analysis

7) When you eat Brussels sprouts, you are eating ________. A) immature flowers B) large axillary buds C) petioles D) storage leaves

B Bloom's Taxonomy: Application/Analysis Section: 35.1

34) As a youngster, you drive a nail in the trunk of a young tree that is 3 meters tall. The nail is about 1.5 meters from the ground. Fifteen years later, you return and discover that the tree has grown to a height of 30 meters. About how many meters above the ground is the nail? A) 0.5 B) 1.5 C) 3.0 D) 15.0

B Bloom's Taxonomy: Application/Analysis Section: 35.3

42) The following diagram is of a cross section of a plant leaf. Use the diagram to answer the question. The main function associated with structure X is ________. A) absorption of carbon dioxide B) retention of water C) collection of light D) release of carbon dioxide

B Bloom's Taxonomy: Application/Analysis Section: 35.3

50) A plant has the following characteristics: a taproot system, several growth rings evident in a cross section of the stem, and a layer of bark around the outside. Which of the following best describes the plant? A) herbaceous eudicot B) woody eudicot C) woody monocot D) herbaceous monocot

B Bloom's Taxonomy: Application/Analysis Section: 35.4

14) Which of the following have unevenly thickened primary walls that support young, growing parts of the plant? A) parenchyma cells B) collenchyma cells C) sclerenchyma cells D) tracheids and vessel elements