121 terms

Exam 3

STUDY
PLAY

Terms in this set (...)

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.
D) the Calvin cycle of photosynthesis.
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
A) C3 photosynthesis
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.
A) nonvascular plants that grew leafless photosynthetic shoots above the shallow fresh water in which they lived.
All of the following normally enter the plant through the roots except

A) carbon dioxide.

B) nitrogen.

C) potassium.

D) water.

E) calcium.
A) carbon dioxide.
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.
C) It transports mainly sugars and amino acids.
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.
E) Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water in tall pine trees without transpiration pull.
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.
E) both the xylem and the phloem.
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
D) concentration of ions in the symplast
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
B) stem xylem
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
A) mesophyll cells of the leaf
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
E) leaf air spaces
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
B) stem tracheary elements
Which of the following essential nutrients plays an essential role in the opening and closing of the stomatal aperture?

A) Fe

B) Bo

C) Mg

D) H

E) K
E) K
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
B) a difference in water potential (Ψ) between the source and the sink
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
D) mature leaf
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.
B) Movement can occur both upward and downward in the plant.
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
B) sugars; leaf; apical meristem
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
C) 2, 4, 3, 1, 5
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
B) endodermis
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 best supports this view?

A) cell wall

B) cell membrane

C) cytosol

D) vacuole

E) plasmodesmata
E) plasmodesmata
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.
C) increase the surface area for absorption.
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
D) the endodermis
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.
D) It ensures that all water and dissolved substances must pass through a cell membrane before entering the stele.
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
C) the evaporation of water from the leaves
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
C) evaporation of water through stoma
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.
D) active transport through xylem cells.
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.
B) The "tension" of this model represents the excitability of the xylem cells.
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) converted to CO2.

E) used to keep cells turgid.
C) lost during transpiration.
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.
C) xylem transport.
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
D) endodermis
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) evaporative cooling and mineral transport.
E) evaporative cooling and mineral transport.
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
B) warm, dry day
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
B) increasing the level of carbon dioxide around the plant
All of the following are adaptations that help reduce water loss from a plant except

A) transpiration.

B) sunken stomata.

C) photosynthesis.

D) small, thick leaves.

E) crassulacean acid metabolism.
A) transpiration.
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
E) plants that do not produce abscisic acid and have a short, thick taproot
Most of the dry weight of a plant is the result of uptake of

A) water and minerals through root hairs.

B) water and minerals through mycorrhizae.

C) CO2 through stoma.

D) CO2 and O2 through stomata
in leaves.

E) carbohydrates in the root hairs and concentration in the root cortex.
C) CO2 through stoma.
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.
B) Companion cells control the rate and direction of movement of phloem sap.
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.
A) solute moves from a high concentration in the source to a lower concentration in the sink.
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
E) bushier plants; higher leaf area indexes
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.
B) root pressure exceeds transpiration pull.
All of the following contributed to the dust bowl in the American southwest during the 1930s except

A) overgrazing by cattle.

B) clear-cutting of forest trees.

C) plowing of native grasses.

D) planting of field crops.

E) lack of soil moisture.
B) clear-cutting of forest trees.
A young farmer purchases some land in a relatively arid area and is interested in earning a reasonable profit for many years. Which of the following strategies would best allow the farmer to achieve such a goal?

A) establishing an extensive irrigation system

B) using plenty of the best fertilizers

C) finding a way to sell all parts of crop plants

D) selecting crops adapted to arid areas

E) converting hillsides into fields
D) selecting crops adapted to arid areas
Which of the following is of least concern to a researcher in a mineral nutrition experiment?

A) purity of the chemicals used to make the nutrient solutions

B) purity of the water used to make the nutrient solutions

C) chemical inertness of the container used to make and store the nutrient solutions

D) ability of a laboratory balance to weigh very small quantities of chemicals

E) medium in which the test seedlings were grown
D) ability of a laboratory balance to weigh very small quantities of chemicals
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) a Casparian strip
B) the interior of a sieve tube
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
A) mycorrhizae
Movement of xylem sap from roots to leaves

A) occurs through the apoplast of sieve-tube elements.

B) usually depends on tension, or negative pressure potential.

C) depends on active transport.

D) depends on the pumping of water through aquaporins.

E) results mainly from diffusion.
B) usually depends on tension, or negative pressure potential.
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
E) positive pressure on the surrounding solution
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.
C) ΨP of +0.35 MPa.
Compared with a cell with few aquaporin proteins in its membrane, a cell containing many aquaporin proteins 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.
A) have a faster rate of osmosis.
A mineral deficiency is likely to affect older leaves more than younger leaves if

A) the mineral is a micronutrient.

B) the mineral is very mobile within the plant.

C) the mineral is required for chlorophyll synthesis.

D) the mineral is a macronutrient.

E) the older leaves are in direct sunlight.
B) the mineral is very mobile within the plant.
Two groups of tomatoes were grown in the laboratory, one with humus added to the soil and the other a control without humus. The leaves of the plants grown without humus were yellowish (less green) compared with those of the plants grown in humus-enriched soil. The best explanation for this difference is that

A) the healthy plants used carbohydrates in the decomposing leaves of the humus for energy to make chlorophyll.

B) the humus made the soil more loosely packed, so water penetrated more easily to the roots.

C) the humus contained minerals such as magnesium and iron, needed for the synthesis of chlorophyll.

D) the heat released by the decomposing leaves of the humus caused more rapid growth and chlorophyll synthesis.

E) the healthy plants absorbed chlorophyll from the humus.
C) the humus contained minerals such as magnesium and iron, needed for the synthesis of chlorophyll.
Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that only animals derive their nutrition by

A) preying on animals.

B) ingesting it.

C) consuming living, rather than dead, prey.

D) using enzymes to digest their food.
B) ingesting it.
Which of the following is (are) unique to animals?

A) cells that have mitochondria

B) the structural carbohydrate, chitin

C) nervous conduction and muscular movement

D) heterotrophy

E) flagellated gametes
C) nervous conduction and muscular movement
A sponge's structural materials (spicules, spongin) are manufactured by the

A) pore cells.

B) epidermal cells.

C) choanocytes.

D) amoebocytes.
D) amoebocytes.
In terms of food capture, which sponge cell is most similar to the cnidocyte of a cnidarian?

A) amoebocyte

B) choanocyte

C) epidermal cell

D) pore cell
B) choanocyte
Sponges are most accurately described as

A) marine predators.

B) chemoautrophs.

C) freshwater scavengers.

D) filter feeders.

E) aquatic predators.
D) filter feeders.
Which of the following characterize at least some members of the phylum Cnidaria?

1. a gastrovascular cavity
2. a polyp stage
3. a medusa stage
4. cnidocytes
5. a pseudocoelom

A) 1

B) 2 and 3

C) 3, 4, and 5

D) 1, 2, 3, and 4

E) All of the above are correct
D) 1, 2, 3, and 4
Which of the following is true of members of the phylum Cnidaria?

A) They are not capable of locomotion because they lack true muscle tissue.

B) They are primarily filter feeders.

C) They have either, or both, of two body forms: mobile polyps and sessile medusae.

D) They may use a gastrovascular cavity as a hydrostatic skeleton.

E) They are the simplest organisms with a complete alimentary canal (two openings).
D) They may use a gastrovascular cavity as a hydrostatic skeleton.
The members of which clade in the phylum Cnidaria occur only as polyps?

A) Hydrozoa

B) Scyphozoa

C) Anthozoa

D) Cubozoa
C) Anthozoa
Which clade in the phylum Cnidaria includes "jellies" with rounded (as opposed to boxlike) medusae?

A) Hydrozoa

B) Scyphozoa

C) Anthozoa

D) Cubozoa
B) Scyphozoa
Which of the following is a diploblastic phylum of aquatic predators?

A) Cnidaria

B) Annelida

C) Mollusca

D) Arthropoda

E) Echinodermata
A) Cnidaria
Corals are most closely related to which group?

A) jellies

B) freshwater hydras

C) sea anemones

D) sponges

E) barnacles
C) sea anemones
The last common ancestor of all animals was probably a

A) unicellular chytrid.

B) unicellular yeast.

C) multicellular algae.

D) multicellular fungus.

E) flagellated protist.
E) flagellated protist.
Evidence of which structure or characteristic would be most surprising to find among fossils of the Ediacaran fauna?

A) true tissues

B) hard parts

C) bilateral symmetry

D) cephalization

E) embryos
B) hard parts
The most ancient branch point in animal phylogeny is that between having

A) radial or bilateral symmetry.

B) a well-defined head or no
head.

C) diploblastic or triploblastic embryos.

D) true tissues or no tissues.

E) a body cavity or no body cavity.
D) true tissues or no tissues.
According to the evidence collected so far, the animal kingdom is

A) monophyletic.

B) paraphyletic.

C) polyphyletic.

D) euphyletic.

E) multiphyletic.
A) monophyletic.
If a multicellular animal lacks true tissues, then it can properly be included among the

A) eumetazoans.

B) metazoans.

C) choanoflagellates.

D) lophotrochozoans.

E) bilateria.
B) metazoans.
Which of the following statements concerning animal taxonomy is (are) true?

1. Animals are more closely related to plants than to fungi.
2. All animal clades based on body plan have been found to be incorrect.
3. Kingdom Animalia is monophyletic.
4. Only animals reproduce by sexual means.
5. Animals are thought to have evolved from flagellated protists similar to modern choanoflagellates.

A) 5 only

B) 1 and 3

C) 3 and 5

D) 3, 4, and 5
C) 3 and 5
If the current molecular evidence regarding animal origins is well substantiated in the future, then what will be true of any contrary evidence regarding the origin of animals derived from the fossil record?

A) The contrary fossil evidence will be seen as a hoax.

B) The fossil evidence will be understood to have been interpreted incorrectly because it is incomplete.

C) The fossil record will henceforth be ignored.

D) Phylogenies involving even the smallest bit of fossil evidence will need to be discarded.

E) Only phylogenies based solely on fossil evidence will need to be discarded.
B) The fossil evidence will be understood to have been interpreted incorrectly because it is incomplete.
Which characteristic(s) is (are) shared by both cnidarians and flatworms?

A) dorsoventrally flattened bodies

B) true muscle

C) radial symmetry

D) a digestive system with a single opening

E) two of these
D) a digestive system with a single opening
Some researchers claim that sponge genomes have homeotic genes, but no Hox genes. If true, this finding would

A) strengthen sponges' evolutionary ties to the Eumetazoa.

B) mean that sponges must no longer be classified as animals.

C) confirm the identity of sponges as "basal animals."

D) mean that extinct sponges must have been the last common ancestor of animals and fungi.

E) require sponges to be reclassified as choanoflagellates.
C) confirm the identity of sponges as "basal animals."
The last common ancestor of all bilaterians is thought to have had four Hox genes. Most extant cnidarians have two Hox genes, except Nematostella (of β-catenin fame), which has three Hox genes. On the basis of these observations, some have proposed that the ancestral cnidarians were originally bilateral and, in stages, lost Hox genes from their genomes. If true, this would mean that

A) Radiata should be a true clade.

B) the radial symmetry of extant cnidarians is secondarily derived, rather than being an ancestral trait.

C) Hox genes play little actual role in coding for an animal's "body plan."

D) Cnidaria may someday replace porifera as the basal bilaterians.

E) cnidarians are the basal metazoans.
B) the radial symmetry of extant cnidarians is secondarily derived, rather than being an ancestral trait.
What do animals as diverse as corals and monkeys have in common?

A) body cavity between body wall and digestive system

B) number of embryonic tissue layers

C) type of body symmetry

D) presence of Hox genes

E) degree of cephalization
D) presence of Hox genes
Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of predator—prey relationships?

A) increased incidence of worm burrows in the fossil record

B) increased incidence of larger animals in the fossil record

C) increased incidence of organic material in the fossil record

D) increased incidence of fern galls in the fossil record

E) increased incidence of hard parts in the fossil record
E) increased incidence of hard parts in the fossil record
Whatever its ultimate cause(s), the Cambrian explosion is a prime example of

A) mass extinction.

B) evolutionary stasis.

C) adaptive radiation.

D) a large meteor impact.
C) adaptive radiation.
An adult animal that possesses bilateral symmetry is most certainly also

A) triploblastic.

B) a deuterostome.

C) eucoelomate.

D) highly cephalized.
A) triploblastic.
At least one of these has been found in all species of eumetazoan animals studied thus far.

A) Hox

B) Dlx

C) Otx

D) FOXP2

E) more than one of these
A) Hox
What is the probable sequence in which the following clades of animals originated, from earliest to most recent?
1. tetrapods
2. vertebrates
3. deuterostomes
4. amniotes
5. bilaterians

A) 5 → 3 → 2 → 4 → 1

B) 5 → 3 → 2 → 1 → 4

C) 5 → 3 → 4 → 2 → 1

D) 3 → 5 → 4 → 2 → 1

E) 3 → 5 → 2 → 1 → 4
B) 5 → 3 → 2 → 1 → 4
Fossil evidence indicates that the following events occurred in what sequence, from earliest to most recent?
1. Protostomes invade terrestrial environments.
2. Cambrian explosion occurs.
3. Deuterostomes invade terrestrial environments.
4. Vertebrates become top predators in the seas.

A) 2 → 4 → 3 → 1

B) 2 → 1 → 4 → 3

C) 2 → 4 → 1 → 3

D) 2 → 3 → 1 → 4

E) 2 → 1 → 3 → 4
C) 2 → 4 → 1 → 3
Which of the following genetic processes may be most helpful in accounting for the Cambrian explosion?

A) binary fission

B) mitosis

C) random segregation

D) gene duplication

E) chromosomal condensation
D) gene duplication
If nudibranch rhinophores are located at the anteriors of these sea slugs, then they contribute to the sea slugs'

A) segmentation.

B) lack of torsion.

C) cephalization.

D) identity as lophotrochozoans.

E) ability to successfully carry out a sessile lifestyle.
C) cephalization.
Which of these, if true, would support the claim that the ancestral cnidarians had bilateral symmetry?
1. Cnidarian larvae possess anterior-posterior, left-right, and dorsal-ventral aspects.
2. Cnidarians have fewer Hox genes than bilaterians.
3. All extant cnidarians, including Nematostella, are diploblastic.
4. β-catenin turns out to be essential for gastrulation in all animals in which it occurs.
5. All cnidarians are acoelomate.

A) 1 only

B) 1 and 4

C) 2 and 3

D) 2 and 4

E) 4 and 5
B) 1 and 4
The Hox genes came to regulate each of the following in what sequence, from earliest to most recent?
1. identity and position of paired appendages in protostome embryos
2. anterior-posterior orientation of segments in protostome embryos
3. positioning of tentacles in cnidarians
4. anterior-posterior orientation in vertebrate embryos

A) 4 → 1 → 3 → 2

B) 4 → 2 → 3 → 1

C) 4 → 2 → 1 → 3

D) 3 → 2 → 1 → 4

E) 3 → 4 → 1 → 2
D) 3 → 2 → 1 → 4
A brachiopod can be distinguished from a bivalve by the presence of

A) two hinged shells.

B) a digestive system with separate mouth and anus.

C) a lophophore.

D) suspension feeding.

E) a distinct head.
C) a lophophore.
Which of the following animal groups is entirely aquatic?

A) Mollusca

B) Crustacea

C) Echinodermata

D) Nematoda

E) Platyhelminthes
C) Echinodermata
Chordate pharyngeal slits appear to have functioned first as

A) the digestive system's opening.

B) suspension-feeding devices.

C) components of the jaw.

D) gill slits for respiration.

E) portions of the inner ear.
B) suspension-feeding devices.
Which of the following statements would be least acceptable to most zoologists?

A) The extant lancelets are contemporaries, not ancestors, of vertebrates.

B) The first fossils resembling lancelets appeared in the fossil record around 530 million years ago.

C) Recent work in molecular systematics supports the hypothesis that lancelets are the basal clade of chordates.

D) The extant lancelets are the immediate ancestors of the fishes.

E) Lancelets display the same method of swimming as do fishes.
D) The extant lancelets are the immediate ancestors of the fishes.
Which extant chordates are postulated to be most like the earliest chordates in appearance?

A) lancelets

B) adult tunicates

C) amphibians

D) reptiles

E) chondrichthyans
A) lancelets
A new species of aquatic chordate is discovered that closely resembles an ancient form. It has the following characteristics: external armor of bony plates, no paired lateral fins, and a suspension-feeding mode of nutrition. In addition to these, it will probably have which of the following characteristics?

A) legs

B) no jaws

C) an amniotic egg

D) endothermy
B) no jaws
How many of the following statements about craniates is (are) correct?
1. Craniates are more highly cephalized than are noncraniate chordates.
2. Craniates' genomic evolution includes duplication of clusters of genes that code for transcription factors.
3. The craniate clade is synonymous with the vertebrate clade.
4. Pharyngeal slits that play a major role in gas exchange originated in craniates.
5. The two-chambered heart originated with the early craniates.

A) only 1 is correct

B) 1 and 5 are correct

C) 2, 3, and 5 are correct

D) 1, 2, 4, and 5 are correct

E) all 5 options are correct
D) 1, 2, 4, and 5 are correct
What do all craniates have that earlier chordates did not have?

A) brain

B) vertebrae

C) cartilaginous pipe surrounding notochord

D) partial or complete skull

E) bone
D) partial or complete skull
Lampreys differ from hagfishes in

A) lacking jaws.

B) having a cranium.

C) having pharyngeal clefts that develop into pharyngeal slits.

D) having a notochord throughout life.

E) having a notochord that is surrounded by a tube of cartilage.
E) having a notochord that is surrounded by a tube of cartilage.
The feeding mode of the extinct conodonts was

A) herbivory.

B) suspension feeding.

C) predation.

D) filter feeding.

E) absorptive feeding.
C) predation.
The earliest known mineralized structures in vertebrates are associated with which function?

A) reproduction

B) feeding

C) locomotion

D) defense

E) respiration
B) feeding
A team of researchers has developed a poison that has proven effective against lamprey larvae in freshwater cultures. The poison is ingested and causes paralysis by detaching segmental muscles from the skeletal elements. The team wants to test the poison's effectiveness in streams feeding Lake Michigan, but one critic worries about potential effects on lancelets, which are similar to lampreys in many ways. Why is this concern misplaced?

A) A chemical poisonous to lampreys could not also be toxic to organisms as ancestral as lancelets.

B) Lamprey larvae and lancelets have very different feeding mechanisms.

C) Lancelets do not have segmental muscles.

D) Lancelets live only in saltwater environments.

E) Lancelets and lamprey larvae eat different kinds of food.
D) Lancelets live only in saltwater environments.
Jaws first occurred in which extant group of fishes?

A) lampreys

B) chondrichthyans

C) ray-finned fishes

D) lungfishes

E) placoderms
B) chondrichthyans
Which of these might have been observed in the common ancestor of chondrichthyans and osteichthyans?

A) a mineralized, bony skeleton

B) opercula

C) bony fin rays

D) a spiral valve intestine

E) a swim bladder
A) a mineralized, bony skeleton
To which of the following are the scales of chondrichthyans most closely related in a structural sense?

A) osteichthyan scales

B) reptilian scales

C) mammalian scales

D) bird scales

E) chondrichthyan teeth
E) chondrichthyan teeth
Which group's members have had both lungs and gills during their adult lives?

A) sharks, skates, and rays

B) lungfishes

C) lancelets

D) amphibians

E) ichthyosaurs and plesiosaurs
B) lungfishes
There is evidence that ray-finned fishes evolved

A) in response to a crisis that wiped out the chondrichthyans.

B) directly from lampreys and hagfish.

C) early in the Cambrian period.

D) directly from lancelets.

E) the swim bladder from a lung.
E) the swim bladder from a lung.
The swim bladder of ray-finned fishes

A) was probably modified from simple lungs of chondrichthyans.

B) developed into lungs in saltwater fishes.

C) first appeared in sharks.

D) provides for regulation of buoyancy.

E) Two of the options listed are correct.
D) provides for regulation of buoyancy.
Which of the following belong to the lobe-fin clade?

A) chondrichthyans

B) ray-finned fishes

C) lampreys

D) hagfishes

E) tetrapods
E) tetrapods
Arrange these taxonomic terms from most inclusive (most general) to least inclusive (most specific).
1. lobe-fins
2. amphibians
3. gnathostomes
4. osteichthyans
5. tetrapods

A) 4, 3, 1, 5, 2

B) 4, 3, 2, 5, 1

C) 4, 2, 3, 5, 1

D) 3, 4, 1, 5, 2

E) 3, 4, 5, 1, 2
D) 3, 4, 1, 5, 2
During chordate evolution, what is the sequence (from earliest to most recent) in which the following structures arose?
1. amniotic egg
2. paired fins
3. jaws
4. swim bladder
5. four-chambered heart

A) 2, 3, 4, 1, 5

B) 3, 2, 4, 1, 5

C) 3, 2, 1, 4, 5

D) 2, 1, 4, 3, 5

E) 2, 4, 3, 1, 5
A) 2, 3, 4, 1, 5
Which of the following are the most abundant and diverse of the extant vertebrates?

A) ray-finned fishes

B) birds

C) amphibians

D) nonbird reptiles

E) mammals
A) ray-finned fishes
What should be true of fossils of the earliest tetrapods?

A) They should show evidence of internal fertilization.

B) They should show evidence of having produced shelled eggs.

C) They should indicate limited adaptation to life on land.

D) They should be transitional forms with the fossils of chondrichthyans that lived at the same time.

E) They should feature the earliest indications of the appearance of jaws.
C) They should indicate limited adaptation to life on land.
Which of these are amniotes?

A) amphibians

B) fishes

C) mammals

D) placental mammals only

E) egg-laying mammals only
C) mammals
Why is the amniotic egg considered an important evolutionary breakthrough?

A) It has a shell that increases gas exchange.

B) It allows deposition of eggs in a terrestrial environment.

C) It prolongs embryonic development.

D) It provides insulation to conserve heat.

E) It permits internal fertilization to be replaced by external fertilization.
B) It allows deposition of eggs in a terrestrial environment.
Which of these characteristics added most to vertebrate success in relatively dry environments?

A) the shelled, amniotic egg

B) the ability to maintain a constant body temperature

C) two pairs of appendages

D) bony scales

E) a four-chambered heart
A) the shelled, amniotic egg
Which of the following are the only extant animals that descended directly from dinosaurs?

A) lizards

B) crocodiles

C) snakes

D) birds

E) tuataras
D) birds
A trend first observed in the evolution of the earliest tetrapods was

A) the appearance of jaws.

B) the appearance of bony vertebrae.

C) feet with digits.

D) the mineralization of the endoskeleton.

E) the amniotic egg.
C) feet with digits.
Among the invertebrate phyla, phylum Arthropoda is unique in possessing members that have

A) a cuticle.

B) a ventral nerve cord.

C) open circulation.

D) wings.

E) segmented bodies.
D) wings.
Arthropods invaded land about 100 million years before vertebrates did so. This most clearly implies that

A) arthropods evolved before vertebrates did.

B) extant terrestrial arthropods are better adapted to terrestrial life than are extant terrestrial vertebrates.

C) ancestral arthropods must have been poorly adapted to aquatic life, and thus experienced a selective pressure to invade land.

D) vertebrates evolved from arthropods.

E) arthropods have had more time to coevolve with land plants than have vertebrates.
E) arthropods have had more time to coevolve with land plants than have vertebrates.
Which of these would a paleontologist be most likely to do in order to determine whether a fossil represents a reptile or a mammal?

A) Look for the presence of milk-producing glands.

B) Look for the mammalian characteristics of a four-chambered heart and a diaphragm.

C) Because mammals are eutherians, look for evidence of a placenta.

D) Use molecular analysis to look for the protein keratin.

E) Examine the teeth.
E) Examine the teeth.
In which vertebrates is fertilization exclusively internal?

A) chondrichthyans, osteichthyans, and mammals

B) amphibians, mammals, and reptiles

C) chondrichthyans, osteichthyans, and reptiles

D) reptiles and mammals

E) reptiles and amphibians
D) reptiles and mammals
Match the extant vertebrate group with the description. Internal fertilization, leathery amniotic egg, and skin that resists drying are characteristics of

A) amphibians.

B) nonbird reptiles.

C) chondrichthyans.

D) mammals.

E) birds.
B) nonbird reptiles.
Which of the following clades contains the greatest number of animal species?

A) the vertebrates

B) the bilaterians

C) the sponges

D) the deuterostomes

E) the insects
B) the bilaterians
Fossil steroid and molecular clock evidence suggests that animals originated

A) between 770 and 710 million years ago.

B) more than 100 million years before the oldest known fossils of large animals.

C) during the Cambrian explosion.

D) after sponges diverged from other metazoans.

E) both A and B
E) both A and B
Which of the following was probably the least important factor in bringing about the Cambrian explosion?

A) the emergence of predator-prey relationships among animals

B) the accumulation of diverse adaptations, such as shells and different modes of locomotion

C) the origin of Hox genes and other genetic changes affecting the regulation of developmental genes

D) the movement of animals onto land

E) the accumulation of sufficient atmospheric oxygen to support the more active metabolism of mobile animals
D) the movement of animals onto land
Which of the following could be considered the most recent common ancestor of living tetrapods?

A) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates

B) an armored gnathostome with two pairs of appendages

C) an early ray-finned fish that developed bony skeletal supports in its paired fins

D) a salamander that had legs supported by a bony skeleton but moved with the side-to-side bending typical of fishes

E) an early terrestrial caecilian whose legless condition had evolved secondarily
A) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates
Which clade does not include humans?

A) synapsids

B) lobe-fins

C) lophotrochozoans

D) tetrapods

E) osteichthyans
C) lophotrochozoans
YOU MIGHT ALSO LIKE...
STUDY GUIDE