Question 1

Which of the following is a feature of gastrulation in both birds and frogs?

Accepted Answer

A)  Three germ layers are established. 
B)  Cells from the surface of the blastocyst migrate to form the gut. 
C)  The neural tube forms from the hypoblast. 
D)  Gastrulation occurs as some cells of the epiblast invaginate to form endoderm and mesoderm. 
E)  All of the above 
A)  Three germ layers are established. 
B)  Cells from the surface of the blastocyst migrate to form the gut. 
C)  The neural tube forms from the hypoblast. 
D)  Gastrulation occurs as some cells of the epiblast invaginate to form endoderm and mesoderm. 
E)  All of the above

Question 2

In frogs, the sperm penetrates

Accepted Answer

A)  in the region of the vegetal pole. 
B)  in the region of the animal pole. 
C)  in the region of the gray crescent. 
D)  on the border of the animal and vegetal poles. 
E)  in the region of either pole or of the gray crescent. 
A)  in the region of the vegetal pole. 
B)  in the region of the animal pole. 
C)  in the region of the gray crescent. 
D)  on the border of the animal and vegetal poles. 
E)  in the region of either pole or of the gray crescent.

Question 3

The process of neurulation in amphibians is similar to that of

Accepted Answer

A)  birds. 
B)  reptiles. 
C)  mammals. 
D)  All of the above 
E)  None of the above 
A)  birds. 
B)  reptiles. 
C)  mammals. 
D)  All of the above 
E)  None of the above

Question 4

The process in development by which germ layers form and take specific positions relative to one another is called _______.

Accepted Answer

The answer of The process in development by which germ...

Question 5

Hans Spemann called the dorsal lip of the blastopore the embryonic organizer because it

Accepted Answer

A)  is the point where gastrulation begins. 
B)  becomes part of the nervous system. 
C)  becomes part of the notochord. 
D)  leads to the establishment of the embryonic axes. 
E)  is the location at which the sperm enters the egg. 
A)  is the point where gastrulation begins. 
B)  becomes part of the nervous system. 
C)  becomes part of the notochord. 
D)  leads to the establishment of the embryonic axes. 
E)  is the location at which the sperm enters the egg.

Question 6

If one of the blastomeres is removed from a developing mouse embryo, the remaining cells will still develop into a normal mouse. This is an example of

Accepted Answer

A)  regulative development. 
B)  determination. 
C)  mosaic development. 
D)  involution. 
E)  ingression. 
A)  regulative development. 
B)  determination. 
C)  mosaic development. 
D)  involution. 
E)  ingression.

Question 7

Which of the following statements about the umbilical cord is false?

Accepted Answer

A)  It contains blood vessels from the embryo. 
B)  It contains blood vessels from the mother. 
C)  It is derived from the allantois. 
D)  It joins the placenta and the embryo. 
E)  It carries nutrients and wastes. 
A)  It contains blood vessels from the embryo. 
B)  It contains blood vessels from the mother. 
C)  It is derived from the allantois. 
D)  It joins the placenta and the embryo. 
E)  It carries nutrients and wastes.

Question 8

Mesenchyme cells are able to move along extracellular matrix molecules by means of

Accepted Answer

A)  amoeboids. 
B)  "walking feet." 
C)  filopodia. 
D)  sliding cell receptors. 
E)  None of the above 
A)  amoeboids. 
B)  "walking feet." 
C)  filopodia. 
D)  sliding cell receptors. 
E)  None of the above

Question 9

Explain how identical and non-identical twins form in humans. Are conjoined twins identical or non-identical twins?

Accepted Answer

Identical (monozygotic) twins are formed

Question 10

Which of the following statements about neural tube defects during development is false?

Accepted Answer

A)  The tube's folds may fail to fuse in the posterior end. 
B)  They are linked to deficiency of folic acid in the diets of pregnant women. 
C)  Spina bifida is one possible result. 
D)  They can lead to the absence of a forebrain in infants. 
E)  All of the above are true; none is false. 
A)  The tube's folds may fail to fuse in the posterior end. 
B)  They are linked to deficiency of folic acid in the diets of pregnant women. 
C)  Spina bifida is one possible result. 
D)  They can lead to the absence of a forebrain in infants. 
E)  All of the above are true; none is false.

Question 11

Placental mammals nourish developing embryos with the maternal circulation and the placenta. Because of this, they have _______ than animals that develop within shelled eggs.

Accepted Answer

A)  less endoderm 
B)  less yolk 
C)  more yolk 
D)  less amnion 
E)  more mesoderm 
A)  less endoderm 
B)  less yolk 
C)  more yolk 
D)  less amnion 
E)  more mesoderm

Question 12

The gray crescent

Accepted Answer

A)  is observable in the frog zygote. 
B)  develops at the site of sperm entry. 
C)  causes rotation of the cortical cytoplasm. 
D)  induces formation of the optic cup. 
E)  can be mimicked by retinoic acid. 
A)  is observable in the frog zygote. 
B)  develops at the site of sperm entry. 
C)  causes rotation of the cortical cytoplasm. 
D)  induces formation of the optic cup. 
E)  can be mimicked by retinoic acid.

Question 13

Once the neural tube is formed, it and the other components of the central nervous system must be connected to the rest of the body. The development of those connections is led by _______ cells.

Accepted Answer

A)  mesothelioma 
B)  neural crest 
C)  Leydig 
D)  somite 
E)  trophoblastic 
A)  mesothelioma 
B)  neural crest 
C)  Leydig 
D)  somite 
E)  trophoblastic

Question 14

The trophoblast helps an early human embryo embed itself in the mother's endometrium

Accepted Answer

A)  after the somites have appeared. 
B)  by secreting enzymes that break down proteins and allow it to enter. 
C)  using cilia extending from the zona pellucida. 
D)  by excreting hydrophobic lipids that cause it to drop out of the uterine fluid and press against the uterine wall. 
E)  None of the above 
A)  after the somites have appeared. 
B)  by secreting enzymes that break down proteins and allow it to enter. 
C)  using cilia extending from the zona pellucida. 
D)  by excreting hydrophobic lipids that cause it to drop out of the uterine fluid and press against the uterine wall. 
E)  None of the above

Question 15

Which of the following play a role as cytoplasmic determinants in directing embryonic development?

Accepted Answer

A)  Transcription factors 
B)  Protein kinases 
C)  Protein kinase inhibitors 
D)  $\beta$-catenin 
E)  All of the above 
A)  Transcription factors 
B)  Protein kinases 
C)  Protein kinase inhibitors 
D)  $\beta$-catenin 
E)  All of the above

Question 16

Birds develop extraembryonic membranes during development. Which of the following statements about avian extraembryonic membranes is false?

Accepted Answer

A)  The yolk sac surrounds the yolk and provides nutrients. 
B)  The amnion and chorion are derived from ectoderm and mesoderm. 
C)  The allantois stores nutrients. 
D)  The chorion exchanges gases and water between the embryo and the environment. 
E)  The allantois is derived from endoderm and mesoderm. 
A)  The yolk sac surrounds the yolk and provides nutrients. 
B)  The amnion and chorion are derived from ectoderm and mesoderm. 
C)  The allantois stores nutrients. 
D)  The chorion exchanges gases and water between the embryo and the environment. 
E)  The allantois is derived from endoderm and mesoderm.

Question 17

Which of the following was a conclusion from the experiments of Spemann and Mangold?

Accepted Answer

A)  Cytoplasmic determinants of development are homogeneously distributed in the amphibian zygote. 
B)  In the late blastula, certain regions of cells are determined to form skin or nervous tissue. 
C)  The dorsal lip of the blastopore can be isolated and will form a complete embryo. 
D)  The dorsal lip of the blastopore can initiate gastrulation. 
E)  The dorsal lip of the blastopore gives rise to the neural tube. 
A)  Cytoplasmic determinants of development are homogeneously distributed in the amphibian zygote. 
B)  In the late blastula, certain regions of cells are determined to form skin or nervous tissue. 
C)  The dorsal lip of the blastopore can be isolated and will form a complete embryo. 
D)  The dorsal lip of the blastopore can initiate gastrulation. 
E)  The dorsal lip of the blastopore gives rise to the neural tube.

Question 18

One function of the allantois is

Accepted Answer

A)  waste storage. 
B)  exchange of respiratory gases. 
C)  the transfer of nutrients. 
D)  control of the pace of development. 
E)  All of the above are functions of the allantois. 
A)  waste storage. 
B)  exchange of respiratory gases. 
C)  the transfer of nutrients. 
D)  control of the pace of development. 
E)  All of the above are functions of the allantois.

Question 19

Exposure to toxins is particularly dangerous to the embryo in the first trimester of pregnancy because

Accepted Answer

A)  its high surface-to-volume ratio provides a great deal of exposure to the toxin. 
B)  rapid cell division is taking place during this period. 
C)  tissue differentiation is occurring at its highest levels during this period. 
D)  branching sequences of developmental pathways are in their early stages in this period. 
E)  b, c, and d 
A)  its high surface-to-volume ratio provides a great deal of exposure to the toxin. 
B)  rapid cell division is taking place during this period. 
C)  tissue differentiation is occurring at its highest levels during this period. 
D)  branching sequences of developmental pathways are in their early stages in this period. 
E)  b, c, and d

Question 20

Bottle cells are

Accepted Answer

A)  cells of the mammalian trophoblast. 
B)  cells of the mammalian inner cell mass. 
C)  fluid-filled cells used for storage. 
D)  bottle-shaped cells found around the amphibian blastopore. 
E)  another name for granulosa cells. 
A)  cells of the mammalian trophoblast. 
B)  cells of the mammalian inner cell mass. 
C)  fluid-filled cells used for storage. 
D)  bottle-shaped cells found around the amphibian blastopore. 
E)  another name for granulosa cells.

Exam 44: Animal Development

Which of the following is a feature of gastrulation in both birds and frogs?

In frogs, the sperm penetrates

The process of neurulation in amphibians is similar to that of

The process in development by which germ layers form and take specific positions relative to one another is called _______.

Hans Spemann called the dorsal lip of the blastopore the embryonic organizer because it

If one of the blastomeres is removed from a developing mouse embryo, the remaining cells will still develop into a normal mouse. This is an example of

Which of the following statements about the umbilical cord is false?

Mesenchyme cells are able to move along extracellular matrix molecules by means of

Explain how identical and non-identical twins form in humans. Are conjoined twins identical or non-identical twins?

Which of the following statements about neural tube defects during development is false?

Placental mammals nourish developing embryos with the maternal circulation and the placenta. Because of this, they have _______ than animals that develop within shelled eggs.

The gray crescent

Once the neural tube is formed, it and the other components of the central nervous system must be connected to the rest of the body. The development of those connections is led by _______ cells.

The trophoblast helps an early human embryo embed itself in the mother's endometrium

Which of the following play a role as cytoplasmic determinants in directing embryonic development?

Birds develop extraembryonic membranes during development. Which of the following statements about avian extraembryonic membranes is false?

Which of the following was a conclusion from the experiments of Spemann and Mangold?

One function of the allantois is

Exposure to toxins is particularly dangerous to the embryo in the first trimester of pregnancy because

Bottle cells are

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 Signaling and Communication

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

Recombinent Dna and Biotechnology

Differential Gene Expression in Development

Development and Evolutionary Change

Evidence and Mechanisms of Evolution

Reconstructing and Using Phylogenies

Species and Their Formation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria and Archaea: the Prokaryotic Domains

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

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 and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Function

Musculoskeletal Systems

Gas Exchange in Animals

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen

Animal Behavior

Ecology and the Distribution of Life

Population Ecology

Species Interaction and Coevolution

Community Ecology

Ecosystems and Global Ecology

Conservation Biology

Filters