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Botany Exam 1

Terms in this set (316)

A(n) ______ includes, by definition, all the organisms in a particular place together with their environment.
ecosystem
The biosphere consists of all the Earth's:
ecosystems
A community consists of all the ______ in a particular area
organisms
Which of the following is not an autotroph?
a. a chemosynthesizer
b. a mushroom
c. an oak tree
d. a green alga
e. a moss
a mushroom
Which of the following is not a primary producer?
a. a cyanobacterium
b. a diatom
c. a lichen
d. a chemosynthesizer
e. a caterpillar
a caterpillar
_______ are primary consumers.
Cows and sheep
A secondary consumer occupies the _______ trophic level.
third
In general, ______ percent of the incident light is incorporated into plant biomass.
less than 1
In general, approximately _____ percent of the energy in one trophic level can be assimilated into the next
10
A fungus is both a(n) ______ and a ______.
heterotroph; decomposer
In an ecosystem, energy flows from:
autotrophs to consumers to decomposers
_______ would be found at the base of a pyramid of energy
Oak trees
Which of the following statements about an upright pyramid of energy is FALSE?
a. It represents the energy relationships among trophic levels.
b. The total energy of producers is represented at the base of the pyramid.
c. The total energy of consumers is greater than the total energy of producers.
d. The total energy of primary carnivores is greater than the total energy of secondary carnivores.
e. The total energy decreases at successively higher trophic levels.
The total energy of consumers is greater than the total energy of producers.
The existence of more grass plants than herbivores in a grassland ecosystem is illustrated by a(n):
pyramid of numbers.
_______ is a fuel formed from wetland biomass that accumulates under standing water.
Peat
Which of the following statements about parasites is FALSE?
a. They live on or in another organism.
b. They are always one trophic level above their hosts.
c. An example is a virus.
d. An example is a pathogenic bacterium.
e. They can be autotrophs or heterotrophs.
They can be autotrophs or heterotrophs.
Competition occurs, by definition, when two individuals living in the same area:
require the same limiting resource.
According to the principle of competitive exclusion, two species with similar requirements:
cannot coexist indefinitely in the same habitat.
In allelopathy:
chemicals produced by one plant inhibit growth of another plant
Mutualism is an interaction between two species in which:
both species benefit.
Which of the following statements about mycorrhizal associations is FALSE?
a. Mycorrhizal fungi grow in or on roots.
b. Mycorrhizal fungi can be species that simply grow near roots.
c. They are found in most vascular plants.
d. They are mutualistic associations.
e. They can be highly specific.
Mycorrhizal fungi can be species that simply grow near roots
______ produced by plants are the most important factors preventing attack by herbivorous insects
Secondary metabolites
What are tannins?
Compounds that make plant proteins indigestible to insects
The seeds of a serotinous cone are released by
fire
T or F? An example of a community is an oak tree and all the organisms that live in and on it.
true
T or F? Energy is recycled in an ecosystem
false
T or F? All autotrophs obtain their energy from the sun.
false
T or F? All plants are autotrophs
false
T or F? An herbivore is a primary consumer; a carnivore is a secondary consumer.
true
T or F? An example of mutualism is nitrogen-fixing bacteria growing in the root nodules of legumes.
true
T or F? In the bull's-horn acacia, Beltian bodies provide food for ants of the genus Pseudomyrmex.
true
T or F? Secondary metabolites are chemicals produced by plants that deter insect herbivores.
true
T or F? "Restoration" ecology refers to efforts by humans to reestablish natural communities.
true
The most extreme deserts are found:
around 30º north and south.
A liana is a(n):
woody vine
Tropical rainforests commonly have ________ species per hectare
100 or more
Which of the following is characterized by having scattered trees and shrubs in a grassland setting
Savanna
In savannas, the dominant plants are:
grasses.
The largest desert in the world is in:
Africa
A hot desert differs from a cold desert in that a cold desert
is characterized by small-leaved shrubs such as sagebrush
The temperate deciduous forest biome:
has precipitation evenly distributed throughout the year
Temperate mixed and temperate deciduous forests differ in that temperate mixed forests:
have more conifers
Giant sequoia trees are characteristically found in the:
mixed West-coast forest.
Which of the following statements about the Arctic tundra is FALSE? a. It is a treeless biome.
b. Fixed nitrogen is in short supply.
c. It lacks permafrost.
d. It lies mostly above the Arctic Circle.
e. The soils are acidic to neutral and low in nutrients.
It lacks permafrost
T or F? A biome refers to a type of relatively homogeneous vegetation occurring over large terrestrial areas
true
T or F? A rain shadow is characterized by abundant rainfall.
false
T or F? In rainforests, relatively little light penetrates to the forest floor.
true
T or F? An example of an epiphyte is a moss.
true
An example of an epiphyte is a moss
sugar and oxygen
Life existed on Earth as early as ______ years ago
3 to 4 billion
Which of the following statements about stromatolites is FALSE?
a. They contain layers of microorganisms.
b. They contain sediment.
c. They are fossil structures, with none alive today.
d. They can be formed by cyanobacteria.
e. They provide information about the earliest forms of life
They are fossil structures, with none alive today
On Mars, there is evidence for the presence of water in the form of______
ice, liquid water and snow
Which of the following statements about proteinoid microspheres is FALSE?
a. They are thought to be the first forms of life.
b. They grow by the accumulation of additional proteinoid material. c. They are cell-like structures.
d. They are assemblages of organic molecules. e. They can be produced in the laboratory
They are thought to be the first forms of life
Which of the following statements concerning primitive cells is FALSE?
a. They used organic molecules to satisfy their energy requirements. b. They constructed new cells from organic molecules made via photosynthesis.
c. They acquired the ability to grow.
d. They acquired the ability to reproduce.
e. They acquired the ability to pass on their characteristics to subsequent generations
They constructed new cells from organic molecules made via photosynthesis
A heterotroph:
is exemplified by a fungus.
Which of the following statements about photosynthetic autotrophs is FALSE?
a. They obtain their required organic compounds from external sources.
b. They channel radiant energy into the biosphere.
c. The word autotroph means "self-feeder."
d. They have a complex pigment system
e. An example of an autotroph is a plant
They obtain their required organic compounds from external sources.
Which of the following statements concerning the earliest photosynthetic organisms is FALSE?
a. They were simple compared to plants.
b. They were more complex than primitive heterotrophs.
c. They had a complex pigment system.
d. They had a way of storing energy in an organic molecule.
e. They have been found in rocks 4 billion years old.
They have been found in rocks 4 billion years old
The oxygen gas released in photosynthesis originates from:
water
Atmospheric levels of oxygen gas approached modern levels approximately ______ years ago
500 million
Ozone in the outer layer of the atmosphere has important consequences for living things in that it:
absorbs ultraviolet rays from sunlight
Respiration refers to the process by which organisms:
break down molecules under aerobic conditions
Prokaryotic cells differ from eukaryotic cells in that prokaryotic cells:
lack a nuclear envelope
Which are prokaryotic organisms?
cyanobacteria and archaea
The first cells on Earth were most likely
archaeans
Which of the following is NOT an adaptation of photosynthetic organisms to rocky coasts?
a. a multicellular body
b. strong cell walls
c. structures to anchor their bodies
d. food-conducting tissues
e. pigment systems
pigment systems
The function of the cuticle is:
retarding water loss.
The function of stomata is:
regulating the exchange of gases
Which of the following statements concerning stomata is FALSE?
a. They form a waxy covering on all aboveground portions of the plant.
b. They consist of a pair of guard cells.
c. They are found in the epidermis.
d. They help maintain a balance between water loss and oxygen and carbon dioxide requirements.
e. They open and close.
They form a waxy covering on all aboveground portions of the plant.
In perennials, the ______ is most similar in function to the cuticle-covered epidermis of annuals.
cork
Water is transported upward through the plant body in the:
xylem
The food manufactured by photosynthesis is transported throughout the plant body in the:
phloem
The function of phloem is to ______
transport food
If a plant is a vascular plant, then by definition that plant must contain ______.
phloem
Secondary growth refers to growth:
originating from lateral meristems.
The activity of the ______ results in a thickening of stems, branches, and roots.
lateral meristems
A seed is composed of three parts:
seed coat, embryo, and food supply.
Natural communities of organisms of wide extent, characterized by distinctive, climatically controlled groups of plants and animals, are called:
biomes
What organisms are found at the base of productivity in almost all ecosystems?
photosynthetic bacteria, algae, and plants only
In all ecosystems, heterotrophs are completely dependent on the productivity of all the following groups of organisms EXCEPT:
a. animals.
b. autotrophs.
c. photosynthetic bacteria.
d. plants.
e. algae
animals
Humans first appeared about ______ years ago.
2 million
The development of agriculture started at least ______ years ago.
10,000
Cytology is the study of:
cell structure, function, and life histories
The projected human population of the Earth by 2050 is _____ billion.
9
The greenhouse effect refers to the:
trapping of heat radiated from Earth.
Phytoremediation refers to the process by which plants:
clean up polluted environments.
T or F? Evidence exists for the presence of ice but not liquid water on Mars
false
T or F? On the early Earth, hydrothermal vents provided one source of organic molecules
true
T or F? Proteinoid microspheres provide evidence that organic molecules in water can aggregate into celllike structures
true
T or F? Just about all organisms use the same genetic code.
true
T or F? Most likely, autotrophs evolved before heterotrophs.
false
T or F? Eukaryotic cells evolved before prokaryotic cells.
false
T or F? Carbon dioxide is the limiting factor for plant growth in the seas
false
T or F? In plants, water moves in a continuous stream from roots to stems to leaves
true
T or F? Perennials have a life-span of only one year
false
T or F? In annuals, the stem becomes woody and covered with cork.
false
T or F? Xylem transports water through the plant body.
true
T or F? Plants that contain xylem and phloem are called vascular plants
true
T or F? Primary growth results in a thickening of the stem and root.
false
T or F? Apical meristems are responsible for the extension of the plant body.
true
T or F? A plant must first exhibit primary growth before it can exhibit secondary growth
true
T or F? An example of a seed plant is a fern.
false
T or F? The evolution of the seed was important because the seed confers protection and nutrition to the embryo.
true
T or F? An ecosystem consists of living organisms and their nonliving environment.
true
T or F? In an ecosystem, elements and energy are recycled.
false
T or F? Plant morphology is the study of the form of plants
true
T or F? Mycorrhizal fungi form symbiotic relationships with their plant hosts
true
T or F? One effect of chlorofluorocarbons has been to deplete the ozone layer.
true
T or F? The greenhouse effect is caused by the trapping of ozone in the stratosphere.
false
T or F? A transgenic plant is one that contains genes from entirely different species.
true
The most abundant organic molecules in nature are:
carbohydrates
Which substance makes up more than half of all living matter and more than 90 percent of the weight of most plant tissues?
Water
_________ is a monosaccharide, and ______________ is a disaccharide
Fructose; lactose
________ is composed of two sugar subunits linked covalently
Sucrose
The common transport form of sugar in plants is ______ and in animals is ______.
sucrose; glucose
The formation of ______ from ______ occurs by dehydration synthesis.
sucrose; glucose and fructose
Which of the following statements about hydrolysis reactions is FALSE?
a. They are energy-yielding reactions.
b. They are a type of condensation reaction.
c. They involve the addition of a molecule of water.
d. An example is the conversion of a polymer to its monomers.
e. An example is the conversion of disaccharides to monosaccharides.
They are a type of condensation reaction
The principal polysaccharide in the plant cell wall is:
cellulose.
What is the most abundant organic compound known?
cellulose
Which of the following consists of beta-glucose subunits?
a. amylose
b. amylopectin
c. chitin
d. cellulose
e. glycogen
cellulose
The matrix of the plant cell wall contains:
pectins and hemicelluloses
Which stabilize the cell wall by forming hydrogen bonds with it?
hemicelluloses
Which comprise most of the middle lamella?
pectins
The principal component of the cell walls of fungi is:
chitin.
The monomer of ___________ is N-acetylglucoseamine.
chitin
When an oil undergoes hydrolysis, the products are:
1 glycerol and 3 fatty acids
Which are examples of triglycerides?
a. oils and fats
b. fats and steroids
c. oils and starches
d. starches and proteins
e. proteins and fats
oils and fats
A fat differs from a phospholipid in that a fat contains:
3 fatty acids
The main function of cutin and suberin is to:
to prevent water loss from the plant cell
Which lipid is a major component of cork cell walls?
suberin
Who am I? I give cell walls a lamellar appearance?
suberin
The most water-repellant of the lipids are:
waxes
Which of the following is characterized by the presence of four interconnected hydrocarbon rings?
steroids
In all organisms except prokaryotes, an important role of sterols is to:
stabilize the phospholipid tails in cell membranes.
The monomers of proteins are:
amino acids.
How many different kinds of amino acids are used to build proteins?
20
A peptide bond occurs between the ______ groups of adjacent amino acids in polypeptides
amino and carboxyl
When a polypeptide undergoes hydrolysis, the products are:
amino acids
The linear sequence of amino acids is called the ______ structure of a protein.
primary
A common ______ structure of proteins involves a hydrogen bond between the amino group of one amino acid and the carboxyl group of an amino acid farther along the peptide chain.
secondary
The tertiary structure of a protein is a result of all of the following EXCEPT:
a. the folding of the secondary structure.
b. the linear sequence of amino acids.
c. the formation of disulfide bridges.
d. interactions among the R groups of a single polypeptide.
e. interactions between two or more polypeptide chains
interactions between two or more polypeptide chains.
The ______ structure of a protein involves interactions between two or more polypeptide chains
quaternary
Which of the following statements about enzymes is FALSE?
a. They are globular proteins.
b. They enable cells to carry out chemical reactions at room temperature.
c. They lower the energy of activation.
d. They can be used over and over again.
e. They are typically effective only at high concentrations
They are typically effective only at high concentrations
Nucleic acids are different from proteins in that nucleic acids contain:
phosphorus.
The monomers of nucleic acids are:
nucleotides.
The subunits of a nucleotide are a(n):
five-carbon sugar, a nitrogenous base, and a phosphate group.
When many nucleotides undergo dehydration synthesis, the product(s) is(are):
a nucleic acid
Adenosine triphosphate is a type of:
nucleotide.
The principal role of ATP in the cell is:
providing energy.
Which of the following statements about secondary metabolites is FALSE?
a. They are found in all cells of a plant.
b. Some function as chemical signals or in the defense of the plant against herbivores.
c. They frequently are synthesized in one part of the plant and stored in another.
d. Some are produced only after the plant has been damaged.
e. Their concentration in a plant can vary greatly over a 24-hour period.
They are found in all cells of a plant.
Which of the following is a primary metabolite?
glucose
The major classes of secondary plant metabolites are:
alkaloids, phenolics, and terpenoids
______ is an alkaloid used to dilate pupils in eye examinations.
Atropine
Who am I? I form a "blanket" that stabilizes photosynthetic membranes and thus helps the plant cope with heat.
isoprene.
Essential oils are types of:
terpenoids
Which of the following secondary metabolites consists of isoprene units?
taxol
The largest group of plant phenolics are the:
flavonoids
______ is a secondary metabolite responsible for adding compressive strength, stiffness, and waterproofing to the plant cell wall.
Lignin
T or F? Only six elements make up 99 percent of the weight of all living matter.
true
T or F? By definition, all organic molecules contain carbon, hydrogen, and oxygen
false
T or F? Pentoses and hexoses have a carbonyl group in the ring form but not the chain form.
false
T or F? Plants break down their carbohydrate reserves and transport starch to the site where it is needed.
false
T or F? Amylose and amylopectin are the two forms of starch.
true
T or F? Starch consists of alpha-glucose subunits, whereas cellulose consists of beta-glucose
true
T or F? Pectins and hemicelluloses constitute the matrix of the plant cell wall in which cellulose microfibrils are embedded.
true
T or F? In contrast to unsaturated fatty acids, saturated fatty acids have one or more kinks that prevent close packing.
false
T or F? Unsaturated fats are usually solid at room temperature
false
T or F? In a phospholipid, the phosphate group is attached directly to the glycerol backbone
true
T or F? In a phospholipid bilayer, each hydrophobic tail is oriented next to a hydrophilic head of the adjacent molecule.
false
T or F? A steroid is characterized by the presence of three interconnected hydrocarbon rings.
false
T or F? A peptide bond is a linkage between an amino group and a carboxyl group.
true
T or F? When a polypeptide is hydrolyzed, many peptide bonds are formed.
false
T or F? All proteins have primary, secondary, tertiary, and quaternary structures.
false
T or F? The denaturation of a protein involves a disruption in its tertiary structure.
true
T or F? A nucleotide consists of a sugar, a phosphate group, and an amino group
false
T or F? DNA molecules are the largest macromolecules found in cells.
true
T or F? An RNA molecule consists of a single strand of nucleotides.
true
T or F? Energy is released in the reaction in which a phosphate group is linked to ADP forming ATP.
false
T or F? Allelopathy is the process by which a chemical produced by one plant inhibits the growth of competitors.
true
T or F? Essential oils, components of plant fragrances, are phenolic compounds.
false
T or F? It is thought that lignin first evolved as a support molecule and only later functioned as an antibacterial and antifungal agent
false
It is thought that lignin first evolved as a support molecule and only later functioned as an antibacterial and antifungal agent
Rudolf Virchow
Eukaryotic cells differ from prokaryotic cells in that eukaryotic cells have:
a nucleus.
Cyclosis refers to:
the constant streaming of the cytoplasm
Which of the following best designates a somatic cell containing 6 chromosomes?
2n = 6
If a plant has a diploid chromosome number of 60, how many chromosomes are present in its gametes?
30
The nucleolus is the structure in which ______ are formed
ribosomes
Grana are stacks of ______ within chloroplasts.
thylakoids
Chlorophylls and carotenoid pigments are embedded in the
thylakoid membranes.
Plastids that contain carotenoids but lack chlorophyll are known as:
chromoplasts.
______ are colorless plastids that are the precursors of other, more highly differentiated plastids.
Proplastids
Which of the following statements about mitochondria is FALSE?
a. They are sites where energy is released from organic molecules.
b. They are generally larger than plastids.
c. They can synthesize some of their own proteins.
d. Their DNA is circular.
e. They are bounded by two membranes.
They are generally larger than plastids.
A pivotal step in programmed cell death is the release of ______ from ______.
cytochrome c; mitochondria
Peroxisomes are organelles that:
self-replicate.
The ______ in the cell sap are responsible for the red and blue colors of many fruits and vegetables.
anthocyanins
Smooth endoplasmic reticulum is involved in ______ synthesis.
lipid
Which of the following lists the correct sequence in which glycoproteins travel through the Golgi complex?
Forming face, shuttle vesicles, maturing face, trans-Golgi network
Which of the following is NOT part of the endomembrane system?
a. tonoplast
b. mitochondrial membrane
c. plasma membrane
d. Golgi complex
e. nuclear envelope
mitochondrial membrane
Which of the following statements about microtubules is FALSE?
a. They are components of the cytoskeleton.
b. Their subunits are assembled at microtubule organizing centers.
c. Their subunits are arranged in a solid cylinder.
d. They are polar structures, with plus and minus ends.
e. They exhibit dynamic instability.
Their subunits are arranged in a solid cylinder.
The alignment of cellulose microfibrils in the cell wall is controlled by:
cortical microtubules.
Which of the following statements concerning actin filaments is FALSE?
a. They are composed of protein subunits.
b. They lack distinct plus and minus ends.
c. They are involved with cell wall deposition.
d. They are involved with cytoplasmic streaming.
e. They are also called micofilaments.
They lack distinct plus and minus ends.
In plants, flagella are found only in:
motile sperm
A ______ has an internal arrangement of nine triplets of microtubules
basal body
Stretching of the cell wall can be prevented by the cross-linking of _____ with _____.
pectins; calcium
Which of the following statements concerning callose is FALSE?
a. It is deposited in response to mechanical wounding.
b. It is associated with aspects of cell division.
c. It consists of spirally wound chains.
d. It is composed of glucose residues.
e. It opens plasmodesmata between contiguous cells.
It opens plasmodesmata between contiguous cells.
Which of the following lists the correct sequence of cell wall layers, beginning with the outermost layer and progressing inward?
a. middle lamella, primary wall, secondary wall
b. secondary wall, primary wall, middle lamella
c. secondary wall, middle lamella, primary wall
d. primary wall, middle lamella, secondary wall
e. middle lamella, secondary wall, primary wall
middle lamella, primary wall, secondary wall
Which of the following statements about the primary wall is FALSE?
a. It is deposited before and during cell growth.
b. It may contain lignin, suberin, or cutin.
c. Actively dividing cells have only primary walls.
d. Some mature plant cells have only a primary wall.
e. It is usually of uniform thickness.
It is usually of uniform thickness
An interruption in the secondary wall is called a:
pit.
Cellulose synthase is an enzyme situated in the:
plasma membrane.
In the cell cycle, interphase consists of:
the G1, G2, and S phases.
Which of the following statements concerning endoreduplication is FALSE?
a. It may result in gigantic nuclei.
b. It involves multiple rounds of DNA synthesis.
c. It provides a mechanism for increasing the level of gene expression.
d. It may result in thousands of copies of each gene.
e. It usually occurs following the differentiation of cells.
It may result in gigantic nuclei.
Which of the following statements concerning checkpoints is FALSE?
a. Checkpoints control the progression between certain phases of the cell cycle.
b. Checkpoints control the rate at which cells are produced.
c. Checkpoints enable a cell to sense whether certain conditions have been met.
d. Checkpoints involve the control of DNA and protein synthesis.
e. Checkpoints differ significantly among eukaryotic cells.
Checkpoints differ significantly among eukaryotic cells.
DNA replication occurs during the ______ phase.
S
Which of the following is unique to cell division in plants?
a. migration of the nucleus to the center of the cell
b. migration of the mitochondria to the periphery of the cell
c. duplication of the centrosome
d. duplication of the mitochondria
e. duplication of the endoplasmic reticulum
migration of the nucleus to the center of the cell
In the developing cell plate, the initial polysaccharide is:
callose.
In late prophase, sister chromatids are joined by a constriction at the:
centromere
The ______ is the earliest manifestation of the mitotic spindle
prophase spindle
Sister chromatids become daughter chromosomes at the beginning of
anaphase.
Chromosomes lengthen and become indistinct during:
telophase.
During ______, the nuclear envelopes and nucleoli re-form
telophase
The longest phase of mitosis is always:
prophase.
Which of the following statements about the phragmoplast is FALSE?
a. It forms between the two daughter nuclei.
b. It is composed of microtubules.
c. Its formation precedes the growth of the cell plate.
d. It begins to form at the walls of the dividing cell and grows inward.
e. In cells with large vacuoles, it is formed within the phragmosome
It begins to form at the walls of the dividing cell and grows inward
T or F? Most prokaryotic cells have only one chromosome.
true
T or F? Prokaryotic cells are characterized by having organelles
false
T or F? The membrane of a vacuole is called the tonoplast.
true
T or F? The largest supramolecular complex assembled in the eukaryotic cell is the nuclear pore.
true
T or F? If a plant has 50 chromosomes in each of its somatic cells, then each of its gametes will have 25 chromosomes
true
T or F? Proplastids that contain prolamellar bodies are called etioplasts.
true
T or F? The outer mitochondrial membrane is called the crista
false
T or F? Most of the increase in size of a plant cell results from enlargement of the vacuole.
true
T or F? Anthocyanins are found in the vacuole
true
T or F? A protein destined for secretion at the cell surface is packaged at the trans-Golgi network into coated vesicles rather than smooth-surfaced vesicles
false
T or F? Substances contained in Golgi vesicles leave the cell by the process of exocytosis
true
T or F? The cytoskeleton of plant cells consists of microtubules, actin filaments, and, in some cases, intermediate filaments.
true
T or F? Once tubulin molecules are joined together they cannot un-join
false
T or F? Flagella and cilia grow out of basal bodies.
true
T or F? Micelles are composed of cellulose.
true
T or F? A compound middle lamella may consist of the middle lamella, the two adjacent primary walls, and the first layer of the secondary wall of each cell.
true
T or F? A primary wall contains pit-fields, but a secondary wall contains pits
true
T or F? An expansin is a protein found in the cell wall
true
T or F? In cells that enlarge in all directions more or less uniformly, microfibrils have been deposited perpendicular to the axis of elongation.
false
T or F? The product of the cellulose synthase enzyme complex is released into the cytoplasm
false
T or F? During winter dormancy, root initials are most likely to be in the G0 phase of the cell cycle
true
T or F? The phragmosome is a sheet of cytoplasm that anchors the nucleus in the center of the cell prior to nuclear division.
true
T or F? At full metaphase, all chromosomes are aligned midway between the spindle poles
true
T or F? Polar microtubules are attached to kinetochores
false
T or F? The most rapid phase of mitosis is anaphase.
true
Who provided the first experimental evidence that soil alone does not nourish the plant?
Jan Baptista van Helmont
The O2 evolved in photosynthesis comes from:
water
F. F. Blackman showed that
photosynthesis has a light-dependent stage and a light-independent stage
Which of the following statements about the electromagnetic spectrum is FALSE?
a. All radiations travel in waves.
b. White light consists of a number of different colors.
c. Different colors of light are refracted at different angles.
d. A wavelength is the distance from one wave crest to the crest of another.
e. The longer the wavelength of light, the more energy it has.
The longer the wavelength of light, the more energy it has.
Light is composed of particles called:
photons
Chlorophyll absorbs light principally in the ______ wavelengths.
blue and violet
An action spectrum is different from an absorption spectrum in that an action spectrum
is the relative effectiveness of different wavelengths for a specific process
Which of the following is the very next event that occurs when a chlorophyll molecule absorbs light?
a. The energy is released as heat.
b. Fluorescence occurs.
c. The electron is boosted to an excited state.
d. Resonance energy transfer occurs.
e. The electron is transferred to an electron transport chain.
The electron is boosted to an excited state
Which pigment occurs in all photosynthetic eukaryotes?
Chlorophyll a
The primary function of ______ is as an anti-oxidant.
carotenoids
Xanthophylls and carotenes:
are carotenoids
The energy-transduction reactions of photosynthesis are also called the ______ reactions
light
Which of the following statements about an antenna complex is FALSE?
a. It is part of a photosystem.
b. It "funnels" energy to the reaction center.
c. It contains chlorophyll molecules.
d. It contains carotenoid pigments.
e. It converts light energy into chemical energy
It converts light energy into chemical energy
The light-harvesting complex is different from a photosystem in that the light-harvesting complex:
lacks a reaction center.
In the antenna complex, light energy is transferred from one pigment molecule to another by:
resonance energy transfer
In contrast to Photosystem I, Photosystem II is located primarily
in grana thylakoids
In Photosystem II, energized electrons are transferred from pheophytin directly to
PQA
In the light reactions, the cytochrome b6/f complex receives electrons directly from:
plastoquinol
Following photolysis, the resulting protons are released into the ______, contributing to the proton gradient across the ______ membrane.
lumen of the thylakoid; thylakoid
The ______ complex links photosystems I and II.
cytochrome b6/f
In photophosphorylation, the role of the ATP synthase complex is to provide a channel for protons to flow back into the:
chloroplast stroma
Which of the following events is NOT associated with Photosystem I
transfer of electrons from cytochromes to iron-sulfur proteins
Which of the following statements concerning ferredoxin is FALSE?
a. It is the final electron acceptor of Photosystem I.
b. It is found in the chloroplast grana.
c. It transfers electrons to NADP+ .
d. It is an iron-sulfur protein.
e. It is a mobile protein.
It is found in the chloroplast grana
Which of the following is produced during noncyclic AND cyclic electron flow?
a. water
b. NADPH
c. sugar
d. ATP
e. O2
ATP
During cyclic electron flow, electrons are transferred directly from P700 to Ao to:
the photosynthetic electron transport chain
The Calvin cycle takes place in the
chloroplast stroma.
Carbon dioxide is "fixed" by bonding to
ribulose 1,5-bisphosphate
The role of Rubisco is to catalyze the conversion of:
CO2 to an unstable six-carbon compound
How many molecules of CO2 are fixed during each turn of the Calvin cycle
One
Which of the following does NOT occur in the Calvin cycle?
a. ATP is hydrolyzed.
b. ADP is phosphorylated to ATP.
c. NADPH is oxidized.
d. Ribulose 1,5-bisphosphate is regenerated.
e. CO2 is fixed.
ADP is phosphorylated to ATP
Which of the following statements about the Calvin cycle is FALSE?
a. It requires more ATP than NADPH.
b. Each reaction is catalyzed by a specific enzyme.
c. It regenerates ribulose 1,5-bisphosphate.
d. It fixes CO2.
e. It uses ATP from noncyclic, but not cyclic, photophosphorylation
It uses ATP from noncyclic, but not cyclic, photophosphorylation
Most of the glyceraldehyde 3-phosphate not exported to the cytosol is converted to ______ and stored in the chloroplasts.
starch
Rubisco can use ______ or CO2 as a substrate
O2
Which of the following statements about photorespiration is FALSE?
a. It yields ATP but not NADPH.
b. Phosphoglycolate is an intermediate.
c. It consumes oxygen and releases CO2.
d. It is a wasteful process.
e. Three cellular organelles participate in the process
It yields ATP but not NADPH
Which of the following conditions favors photorespiration?
a. a ratio of CO2 to O2 that favors CO2
b. conditions that cause the stomata to open
c. plants growing far apart
d. a hot, dry environment
e. darkness 36. One of the benefits of
a hot, dry environment
One of the benefits of photorespiration is removing toxic
phosphoglycolate
In the C4 pathway, the enzyme PEP carboxylase:
catalyzes the formation of oxaloacetate
The malate or aspartate produced in the C4 pathway moves next into
the bundle-sheath cells
Kranz anatomy is characterized by a layer of ____ around a layer of ___
mesophyll cells; bundle-sheath cells
Suaeda aralocaspica is different from many other C4 plants because it
lacks Kranz anatomy.
Compared with a C3 plant, a C4 plant
needs more ATP to fix CO2
Which of the following is a C4 plant?
a. rice
b. oats
c. Kentucky bluegrass
d. crabgrass
e. wheat
crabgrass
Compared with C3 plants, C4 plants:
use nitrogen more efficiently
In CAM plants, malate formed as the end product of CO2 fixation in the dark is stored as malic acid in the:
vacuole
Which of the following is most likely to occur in a leaf cell of a CAM plant during the day?
a. entry of CO2 through stomata
b. exit of water through stomata
c. decarboxylation of malic acid
d. fixation of CO2 by PEP carboxylase
e. conversion of oxaloacetate to malate
decarboxylation of malic acid
Which of the following is not considered a CAM plant?
a. cactus
b. pineapple
c. Spanish "moss"
d. Welwitschia
e. wheat
wheat
Which of the following statements about CAM plants is FALSE?
a. Not all CAM plants are succulent.
b. All CAM plants are flowering plants.
c. They use both C3 and C4 pathways.
d. They are dependent on nighttime accumulation of CO2 for photosynthesis.
e. Their water-use efficiency is higher than that of C3 and C4 plants.
All CAM plants are flowering plants
T or F? C. B. van Neil's experiments provided evidence that water, not carbon dioxide, was the source of the oxygen in photosynthesis.
true
T or F? The energy of a photon of light is directly proportional to its wavelength
false
T or F? Chlorophyll absorbs light principally in the green wavelength
false
T or F? An action spectrum can be used to demonstrate the relative effectiveness of different wavelengths of light for photosynthesis
true
T or F? Accessory pigments are directly involved in the energy-transduction processes of photosynthesis
false
T or F? All photosynthetic eukaryotes contain both chlorophylls a and b
false
T or F? Phycobilins are water-soluble accessory pigments found in cyanobacteria and red algae.
true
T or F? The light-harvesting complex contains does not contain a reaction center
true
T or F? At the reaction center of Photosystem II is P700
false
T or F? In Photosystem II, pheophytin passes an electron directly to plastoquinone.
true
T or F? The photolysis of water occurs in conjunction with Photosystem II but not Photosystem I
true
T or F? The cytochrome b6/f complex links Photosystems II and I
true
T or F? Protons flow through the ATP synthesis from the stroma into the thylakoid lumen.
false
T or F? In the process of cyclic photophosphorylation, both ATP and NADPH are produced
false
T or F? The ATP and NADPH generated by the light reactions are used in the Calvin cycle
true
T or F? Rubisco can use either O2 or CO2 as a substrate
true
T or F? Photorespiration is an energetically wasteful process that seldom occurs in nature
false
T or F? The concentration of CO2 in the Earth's atmosphere is approximately 3 percent
false
T or F? One of the benefits of photorespiration is to remove phosphoglycolate from the plant
true
T or F? The leaf anatomy of C4 plants provides a spatial separation between the C4 pathway and the Calvin cycle
true
T or F? C3-C4 intermediates provide evidence for the evolution of C3 plants from C4 ancestors
false
T or F? Some CAM plants can keep their stomata closed night and day
true
T or F? Under extremely dry conditions, CAM plants outcompete C3 and C4 plants
true
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