Question 1

Photosynthesis begins to decline when leaves wilt because

Accepted Answer

A) chloroplasts within wilted cells 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, preventing CO2 entry into the leaf. 
E) Wilted cells cannot absorb the red and blue wavelengths of light. 
A) chloroplasts within wilted cells 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, preventing CO2 entry into the leaf. 
E) Wilted cells cannot absorb the red and blue wavelengths of light.

Question 2

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

Accepted Answer

A) evaporative cooling. 
B) mineral transport. 
C) increased turgor. 
D) A and B only 
E) A, B, and C 
A) evaporative cooling. 
B) mineral transport. 
C) increased turgor. 
D) A and B only 
E) A, B, and C

Question 3

What is the main cause of guttation in plants?

Accepted Answer

A) root pressure 
B) transpiration 
C) pressure flow in phloem 
D) plant injury 
E) condensation of atmospheric water 
A) root pressure 
B) transpiration 
C) pressure flow in phloem 
D) plant injury 
E) condensation of atmospheric water

Question 4

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?

Accepted Answer

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 
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

Question 5

Which of the following has the lowest (most negative)water potential?

Accepted Answer

A) soil 
B) root xylem 
C) trunk xylem 
D) leaf cell walls 
E) leaf air spaces 
A) soil 
B) root xylem 
C) trunk xylem 
D) leaf cell walls 
E) leaf air spaces

Question 6

Root hairs are most important to a plant because they

Accepted Answer

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. 
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.

Question 7

Active transport of various materials in plants at the cellular level requires all of the following except

Accepted Answer

A) a proton gradient. 
B) ATP. 
C) membrane potential. 
D) transport proteins 
E) xylem membranes. 
A) a proton gradient. 
B) ATP. 
C) membrane potential. 
D) transport proteins 
E) xylem membranes.

Question 8

What is the main force by which most of the water within xylem vessels moves toward the top of a tree?

Accepted Answer

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 
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

Question 9

Guard cells do which of the following?

Accepted Answer

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 
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

Question 10

The ancestors of land plants were aquatic algae. Which of the following is not an evolutionary adaptation to life on land?

Accepted Answer

A) C3 photosynthesis 
B) a waxy cuticle 
C) root hairs 
D) xylem and phloem 
E) guard cells 
A) C3 photosynthesis 
B) a waxy cuticle 
C) root hairs 
D) xylem and phloem 
E) guard cells

Question 11

Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant?

Accepted Answer

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 
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

Question 12

Movement of phloem sap from a source to a sink

Accepted Answer

A) occurs through the apoplast of sieve-tube elements. 
B) may translocate sugars from the breakdown of stored starch in a root up to developing shoots. 
C) depends on tension, or negative pressure potential. 
D) depends on pumping water into sieve tubes at the source. 
E) results mainly from diffusion. 
A) occurs through the apoplast of sieve-tube elements. 
B) may translocate sugars from the breakdown of stored starch in a root up to developing shoots. 
C) depends on tension, or negative pressure potential. 
D) depends on pumping water into sieve tubes at the source. 
E) results mainly from diffusion.

Question 13

In which plant cell or tissue would the pressure component of water potential most often be negative?

Accepted Answer

A) leaf mesophyll cell 
B) stem xylem 
C) stem phloem 
D) root cortex cell 
E) root epidermis 
A) leaf mesophyll cell 
B) stem xylem 
C) stem phloem 
D) root cortex cell 
E) root epidermis

Question 14

The apoplast is the cytoplasmic continuum linked by plasmodesmata. The symplast is the continuum of cell walls and extracellular spaces.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following statements is False concerning the xylem?

Accepted Answer

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; materials move owing to a 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. 
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; materials move owing to a 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.

Question 16

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

Accepted Answer

A) -0.23 MPa. 
B) +0.23 MPa. 
C) +0.07 MPa. 
D) -0.0000001 MPa. 
E) 0.0 (zero). 
A) -0.23 MPa. 
B) +0.23 MPa. 
C) +0.07 MPa. 
D) -0.0000001 MPa. 
E) 0.0 (zero).

Question 17

Which of the following statements about xylem is incorrect?

Accepted Answer

A) It conducts material upward. 
B) It conducts materials within dead cells. 
C) It transports mainly sugars and amino acids. 
D) It has a lower water potential than soil does. 
E) No energy input from the plant is required for xylem transport. 
A) It conducts material upward. 
B) It conducts materials within dead cells. 
C) It transports mainly sugars and amino acids. 
D) It has a lower water potential than soil does. 
E) No energy input from the plant is required for xylem transport.

Question 18

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

Accepted Answer

A) mycorrhizae 
B) cavitation 
C) active uptake 
D) rhythmic contraction by cortical cells 
E) pumping through plasmodesmata 
A) mycorrhizae 
B) cavitation 
C) active uptake 
D) rhythmic contraction by cortical cells 
E) pumping through plasmodesmata

Question 19

Guard cells are the only cells in the epidermis that contain chloroplasts and can undergo photosynthesis. This is important because

Accepted Answer

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) A and C 
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) A and C

Question 20

In plant roots, the Casparian strip is correctly described by which of the following?

Accepted Answer

A) It is located in the walls between endodermal cells and cortex cells. 
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. 
A) It is located in the walls between endodermal cells and cortex cells. 
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.

Exam 36: Transport in Vascular Plants

Photosynthesis begins to decline when leaves wilt because

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

What is the main cause of guttation in plants?

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?

Which of the following has the lowest (most negative)water potential?

Root hairs are most important to a plant because they

Active transport of various materials in plants at the cellular level requires all of the following except

What is the main force by which most of the water within xylem vessels moves toward the top of a tree?

Guard cells do which of the following?

The ancestors of land plants were aquatic algae. Which of the following is not an evolutionary adaptation to life on land?

Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant?

Movement of phloem sap from a source to a sink

In which plant cell or tissue would the pressure component of water potential most often be negative?

The apoplast is the cytoplasmic continuum linked by plasmodesmata. The symplast is the continuum of cell walls and extracellular spaces.

Which of the following statements is False concerning the xylem?

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

Which of the following statements about xylem is incorrect?

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

Guard cells are the only cells in the epidermis that contain chloroplasts and can undergo photosynthesis. This is important because

In plant roots, the Casparian strip is correctly described by which of the following?

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and the Fitness of the Environment

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Control of Gene Expression

Viruses

Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure, Growth, and Development

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems

Conservation Biology and Restoration Ecology

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