Question 1

The _______ is the primary embryonic organizer in amphibians.

Accepted Answer

A)  archenteron 
B)  dorsal lip of the blastopore 
C)  ectoderm 
D)  blastocoel 
E)  bottle cell 
A)  archenteron 
B)  dorsal lip of the blastopore 
C)  ectoderm 
D)  blastocoel 
E)  bottle cell

Question 2

Refer to the figure showing implantation in humans.   Based on the figure, which statement is true?

Accepted Answer

A)  The embryo proper develops from the structure at point 8. 
B)  The stage of embryonic development depicted is early cleavage. 
C)  The structure at point 7 secretes proteolytic enzymes that aid implantation. 
D)  The structure at point 8 is formed when cells of the structure at point 6 secrete fluid. 
E)  The structure at point 10 develops from the structure at point 9. 
A)  The embryo proper develops from the structure at point 8. 
B)  The stage of embryonic development depicted is early cleavage. 
C)  The structure at point 7 secretes proteolytic enzymes that aid implantation. 
D)  The structure at point 8 is formed when cells of the structure at point 6 secrete fluid. 
E)  The structure at point 10 develops from the structure at point 9.

Question 3

A _______ is an embryo with a central fluid cavity called a _______.

Accepted Answer

A)  blastomere; blastocoel 
B)  blastomere; blastula 
C)  blastula; blastomere 
D)  blastula; blastocoel 
E)  gastrula; blastula 
A)  blastomere; blastocoel 
B)  blastomere; blastula 
C)  blastula; blastomere 
D)  blastula; blastocoel 
E)  gastrula; blastula

Question 4

If you were interested in studying spiral cleavage, from which group would you select your study species?

Accepted Answer

A)  Frogs 
B)  Mollusks 
C)  Birds 
D)  Fishes 
E)  Insects 
A)  Frogs 
B)  Mollusks 
C)  Birds 
D)  Fishes 
E)  Insects

Question 5

If an embryo exhibits abnormal development of peripheral nerves, the source of the problem is most likely damage or impairment of

Accepted Answer

A)  the neural tube. 
B)  neural crest cells. 
C)  endoderm. 
D)  somites. 
E)  the notochord. 
A)  the neural tube. 
B)  neural crest cells. 
C)  endoderm. 
D)  somites. 
E)  the notochord.

Question 6

Which statement about cleavage in placental mammals is true?

Accepted Answer

A)  As in other animals, the loose ball of cells at the 8-cell stage of mammals becomes asymmetrical when cells form tight junctions and increase contact with one another. 
B)  Unlike cleavage in sea urchins and frogs, gene products expressed by blastomeres affect cleavage in mammals. 
C)  As in sea urchins and frogs, the number of cells in the embryo increases in a regular progression from 1 to 2 to 4 to 8 to 16 to 32, and so on. 
D)  In the second division, cleavage divides the blastomeres in a plane that is perpendicular to the animal-vegetal axis. 
E)  At the end of cleavage, the embryo is called a blastocyst because it lacks a blastocoel. 
A)  As in other animals, the loose ball of cells at the 8-cell stage of mammals becomes asymmetrical when cells form tight junctions and increase contact with one another. 
B)  Unlike cleavage in sea urchins and frogs, gene products expressed by blastomeres affect cleavage in mammals. 
C)  As in sea urchins and frogs, the number of cells in the embryo increases in a regular progression from 1 to 2 to 4 to 8 to 16 to 32, and so on. 
D)  In the second division, cleavage divides the blastomeres in a plane that is perpendicular to the animal-vegetal axis. 
E)  At the end of cleavage, the embryo is called a blastocyst because it lacks a blastocoel.

Question 7

Which feature characterizes gastrulation?

Accepted Answer

A)  Increased rate of mitosis 
B)  Massive cell movements 
C)  Formation of differentiated tissues 
D)  Establishment of the dorsal-ventral body axis, but not the anterior-posterior axis 
E)  Separation of tissue layers, preventing interactions between them 
A)  Increased rate of mitosis 
B)  Massive cell movements 
C)  Formation of differentiated tissues 
D)  Establishment of the dorsal-ventral body axis, but not the anterior-posterior axis 
E)  Separation of tissue layers, preventing interactions between them

Question 8

Refer to the figure showing fertilization in an amphibian egg.   Predict where the gray crescent will form and what region of the embryo this will mark.

Accepted Answer

A)  It will form at point "a" and mark the dorsal region. 
B)  It will form at point "b" and mark the ventral region. 
C)  It will form at point "c" and mark the dorsal region. 
D)  It will form at point "d" and mark the ventral region. 
E)  It will form at point "a" and mark the ventral region. 
A)  It will form at point "a" and mark the dorsal region. 
B)  It will form at point "b" and mark the ventral region. 
C)  It will form at point "c" and mark the dorsal region. 
D)  It will form at point "d" and mark the ventral region. 
E)  It will form at point "a" and mark the ventral region.

Question 9

At which location in the frog embryo is glycogen synthase kinase-3 (GSK-3) inhibited?

Accepted Answer

A)  Inner cytoplasm of ventral side 
B)  Cortical cytoplasm of vegetal pole 
C)  Animal pole 
D)  Inner cytoplasm of dorsal side 
E)  Site of sperm entry 
A)  Inner cytoplasm of ventral side 
B)  Cortical cytoplasm of vegetal pole 
C)  Animal pole 
D)  Inner cytoplasm of dorsal side 
E)  Site of sperm entry

Question 10

Both the amnion and chorion of a developing chick

Accepted Answer

A)  are formed by ectoderm and endoderm. 
B)  secrete fluid that protects the embryo. 
C)  function in the exchange of respiratory gases. 
D)  are formed by ectoderm and mesoderm. 
E)  form before the yolk sac does. 
A)  are formed by ectoderm and endoderm. 
B)  secrete fluid that protects the embryo. 
C)  function in the exchange of respiratory gases. 
D)  are formed by ectoderm and mesoderm. 
E)  form before the yolk sac does.

Question 11

Which is the correct matching of term and definition as they relate to gastrulation in frogs?

Accepted Answer

A)  Involution-process by which surface cells change their shape in order to invaginate into the blastocoel 
B)  Bottle cells-cells in the gray crescent region that bulge inward while remaining attached to the outer surface of the blastula 
C)  Epiboly-process by which vegetal hemisphere cells flatten and move inward 
D)  Blastocoel-fluid-filled cavity that enlarges as the archenteron enlarges 
E)  Dorsal lip of the blastopore-cells that form the neural tube of the embryo 
A)  Involution-process by which surface cells change their shape in order to invaginate into the blastocoel 
B)  Bottle cells-cells in the gray crescent region that bulge inward while remaining attached to the outer surface of the blastula 
C)  Epiboly-process by which vegetal hemisphere cells flatten and move inward 
D)  Blastocoel-fluid-filled cavity that enlarges as the archenteron enlarges 
E)  Dorsal lip of the blastopore-cells that form the neural tube of the embryo

Question 12

Which statement about frog eggs and early development is true?

Accepted Answer

A)  The haploid nucleus of the egg is located in the vegetal hemisphere where the yolk is concentrated. 
B)  Sperm binding sites occur only on the surface of the animal hemisphere. 
C)  Distribution of the transcription factor β-catenin becomes concentrated in the animal hemisphere following rotation of the cortical cytoplasm. 
D)  The site of sperm entry will become the posterior region of the embryo. 
E)  The gray crescent will become the ventral region of the embryo. 
A)  The haploid nucleus of the egg is located in the vegetal hemisphere where the yolk is concentrated. 
B)  Sperm binding sites occur only on the surface of the animal hemisphere. 
C)  Distribution of the transcription factor β-catenin becomes concentrated in the animal hemisphere following rotation of the cortical cytoplasm. 
D)  The site of sperm entry will become the posterior region of the embryo. 
E)  The gray crescent will become the ventral region of the embryo.

Question 13

Which is a shared feature of the embryonic development of chicks and placental mammals?

Accepted Answer

A)  Cells migrate through a midline primitive groove during gastrulation. 
B)  The body of the embryo forms on top of a large yolk mass. 
C)  The hypoblast forms when cells of the blastodisc break free and form a continuous layer below the blastocoel. 
D)  Hensen's node forms the neural tube. 
E)  The hypoblast forms the body of the embryo. 
A)  Cells migrate through a midline primitive groove during gastrulation. 
B)  The body of the embryo forms on top of a large yolk mass. 
C)  The hypoblast forms when cells of the blastodisc break free and form a continuous layer below the blastocoel. 
D)  Hensen's node forms the neural tube. 
E)  The hypoblast forms the body of the embryo.

Question 14

The rod that forms from the chordamesoderm and lends structural support to the developing embryo is called the _______.

Accepted Answer

The answer of The rod that forms from the chordamesoderm...

Question 15

Which statement about neural crest cells is true?

Accepted Answer

A)  Neural crest cells give rise to the central nervous system. 
B)  Body segmentation develops because of migration of neural crest cells. 
C)  Neural crest cells are derived from the epidermal ectoderm. 
D)  Neural crest cells are migratory. 
E)  Neural crest cells form the brain and spinal cord. 
A)  Neural crest cells give rise to the central nervous system. 
B)  Body segmentation develops because of migration of neural crest cells. 
C)  Neural crest cells are derived from the epidermal ectoderm. 
D)  Neural crest cells are migratory. 
E)  Neural crest cells form the brain and spinal cord.

Question 16

Refer to the figure showing an embryo during early cleavage.   How do you know that this embryo is not that of a frog?

Accepted Answer

The cleavages in this embryo a

Question 17

You find a microscope slide labeled "Whole mount of early cleavage stage embryo," but the part of the label identifying the organism is missing.Upon observing the embryo under the microscope, you see that the embryo was mounted when it was undergoing its second cleavage and that the two cleavage planes are at a right angle.From this, you are able to conclude that the embryo is from a(n)

Accepted Answer

A)  fish and was most likely found floating freely in water. 
B)  bird and was obtained after the egg had been laid. 
C)  amphibian and was most likely found encased in jelly in water. 
D)  placental mammal and was most likely removed from a female's oviduct. 
E)  fruit fly and was most likely from an old laboratory experiment. 
A)  fish and was most likely found floating freely in water. 
B)  bird and was obtained after the egg had been laid. 
C)  amphibian and was most likely found encased in jelly in water. 
D)  placental mammal and was most likely removed from a female's oviduct. 
E)  fruit fly and was most likely from an old laboratory experiment.

Question 18

An ectopic pregnancy results when

Accepted Answer

A)  implantation occurs in an oviduct. 
B)  fertilization occurs in the uterus. 
C)  fertilization occurs in an ovary. 
D)  implantation occurs in the endometrium of the uterus. 
E)  cleavage occurs along the length of an oviduct. 
A)  implantation occurs in an oviduct. 
B)  fertilization occurs in the uterus. 
C)  fertilization occurs in an ovary. 
D)  implantation occurs in the endometrium of the uterus. 
E)  cleavage occurs along the length of an oviduct.

Question 19

A researcher studying the development of the eye in Xenopus (the clawed frog) is testing her hypothesis that the optic vesicle induces head ectoderm to form the lens of the eye.When she removes the optic vesicle on one side of the embryo, no lens forms on that side, indicating the optic vesicle is necessary for lens formation.What additional experimental result must she obtain to show that the optic vesicle is also sufficient for inducing lens formation?

Accepted Answer

A)  The lens forms when a permeable barrier is placed between the optic vesicle and the lens-forming tissue. 
B)  The lens does not form when an impermeable barrier is placed between the optic vesicle and the lens-forming tissue. 
C)  A lens forms when the optic vesicle is placed next to tissue that does not normally form a lens. 
D)  A lens does not form when the optic vesicle is placed next to tissue that does not normally form a lens. 
E)  A lens forms when the optic vesicle is recombined with lens-forming tissue. 
A)  The lens forms when a permeable barrier is placed between the optic vesicle and the lens-forming tissue. 
B)  The lens does not form when an impermeable barrier is placed between the optic vesicle and the lens-forming tissue. 
C)  A lens forms when the optic vesicle is placed next to tissue that does not normally form a lens. 
D)  A lens does not form when the optic vesicle is placed next to tissue that does not normally form a lens. 
E)  A lens forms when the optic vesicle is recombined with lens-forming tissue.

Question 20

The "water breaking" often marks the onset of labor in humans.Which extraembryonic membrane(s) rupture(s) at this time?

Accepted Answer

A)  Amnion only 
B)  Chorion only 
C)  Amnion and chorion 
D)  Amnion and yolk sac 
E)  Amnion and allantois 
A)  Amnion only 
B)  Chorion only 
C)  Amnion and chorion 
D)  Amnion and yolk sac 
E)  Amnion and allantois

Exam 43: Animal Development

The _______ is the primary embryonic organizer in amphibians.

Refer to the figure showing implantation in humans. Based on the figure, which statement is true?

A _______ is an embryo with a central fluid cavity called a _______.

If you were interested in studying spiral cleavage, from which group would you select your study species?

If an embryo exhibits abnormal development of peripheral nerves, the source of the problem is most likely damage or impairment of

Which statement about cleavage in placental mammals is true?

Which feature characterizes gastrulation?

Refer to the figure showing fertilization in an amphibian egg. Predict where the gray crescent will form and what region of the embryo this will mark.

At which location in the frog embryo is glycogen synthase kinase-3 (GSK-3) inhibited?

Both the amnion and chorion of a developing chick

Which is the correct matching of term and definition as they relate to gastrulation in frogs?

Which statement about frog eggs and early development is true?

Which is a shared feature of the embryonic development of chicks and placental mammals?

The rod that forms from the chordamesoderm and lends structural support to the developing embryo is called the _______.

Which statement about neural crest cells is true?

Refer to the figure showing an embryo during early cleavage. How do you know that this embryo is not that of a frog?

An ectopic pregnancy results when

The "water breaking" often marks the onset of labor in humans.Which extraembryonic membrane(s) rupture(s) at this time?

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinant Dna and Biotechnology

Mechanisms of Evolution

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Neurons, Glia, and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Functions

Musculoskeletal Systems

Gas Exchange

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

Populations

Species Interactions

Communities

Ecosystems

A Changing Biosphere

Filters

A _ is an embryo with a central fluid cavity called a _.