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Example Questions
Example Question #1 : Gastrulation And Embryonic Germ Layers
The mesoderm germ layer eventually gives rise to the formation of the __________.
nervous system
muscles
lining of the digestive system
epidermis
lining of the respiratory system
muscles
The mesoderm gives rise to the muscles among other structures. The other answers are derived from the ectoderm or endoderm.
Example Question #1 : Gastrulation And Embryonic Germ Layers
The thyroid gland arises from this embryonic layer __________.
I. neuroectoderm
II. ectoderm
III. mesoderm
IV. endoderm
V. ectoderm with contributions from mesoderm
II
V
I
IV
III
IV
Many of the glandular structures—both exocrine and endocrine—arise from endoderm. In particular, both the thyroid and parathyroid glands bud off from the pharyngeal mucosa, which of course is endodermal in character. Of course, like all tissues, there are mesodermal components of the gland in the way of connective tissues and blood vessels. The response indicating a mesodermal component invites you to make a wrong selection because you could remember that there are mesodermal-derived tissues everywhere, but you could not specifically recall the origin of the thyroid tissue, itself.
Example Question #60 : Biology
Which of the following is NOT a major germ layer formed during gastrulation?
Cytoderm
Mesoderm
Ectoderm
Endoderm
Cytoderm
The correct answer is cytoderm.
There are three major germ layers formed during gastrulation: the ectoderm, mesoderm, and endoderm. Major structures form from these germ layers over the course of embryogenesis and development.
Example Question #1 : Gastrulation And Embryonic Germ Layers
A newly born child is having difficulty breathing and digesting food. A close medical examination has revealed an improperly formed inner lining to the digestive and respiratory systems. Which of the following is the most likely cause of the medical problem?
A disruption of the mesoderm during development
Genetic abnormalities in both the mesoderm and ectoderm
There is not enough information to determine a likely cause
An abnormality has occurred in the development of the endoderm
A disease affecting the ectoderm germ layer
An abnormality has occurred in the development of the endoderm
Gastrulation is the formation of the three layers of the embryo: ectoderm, endoderm, and mesoderm. The endoderm gives rise to the lining of the digestive system and respiratory system. A defect in these tissues suggests a problem of that germ layer during development. The ectoderm gives rise to the nervous system and epidermis. The mesoderm gives rise to the muscle and skeletal systems.
Example Question #1 : Gastrulation And Embryonic Germ Layers
The kidneys arise from which of the three embryonic germ layers?
Ectoderm
Mesoderm
Notochord region
Endoderm
None of these choices are correct
Mesoderm
The three embryonic germ layers are the ectoderm, mesoderm, and endoderm. The mesoderm gives rise to bone, muscle, the urinary system, and the kidneys. Ectoderm develops into the nervous system, dermis, hair, nails, eyes, and ears. The endoderm develops into the lining of internal organs, such as the lungs and the gastrointestinal tract. The notochord is not an embryonic layer and, like the kidneys, arises from the mesoderm.
Example Question #1 : Gastrulation And Embryonic Germ Layers
What happens during the process of gastrulation?
The three primary germ layers are created
The blastomeres undergo compaction
The epiblast and hypoblast are created
The cell divides into the eight-cell stage
The ectoderm differentiates into epithelial tissue
The three primary germ layers are created
The process of gastrulation generates the three primary germ layers (ectoderm, endoderm, mesoderm). This is one of the most important steps of development.
The eight-cell stage signals the beginning of compaction, during which the cells of the blastula adhere to each other and prepare for further divisions. The epiblast and hypoblast are generated before gastrulation, but after implantation. Differentiation occurs long after the primary germ layers are formed.
Example Question #1 : Gastrulation And Embryonic Germ Layers
A new born is assesed to have congenital nerve conduction defects. From which germ layer would this problem originate?
Ectoderm
Gastrula
Blastula
Mesoderm
Endoderm
Ectoderm
The correct answer is the ectoderm. The ectoderm is responsible for generating nervous tissue and glial cells, among other features.
Ectoderm differntiates into the epidermis, nervous system, eye lens, and hair.
Mesoderm differentiates into muscle, cardiac and skeletal systems, blood, and spleen.
Endoderm differentiates into the lining of internal organs, like the digestive tract and respiratory tract.
Example Question #51 : Systems Biology And Tissue Types
Which cell type is occasionally called "the fourth germ layer" due to its migratory properties and critical developmental importance?
Hepatocytes
Beta cells
Neural crest
Cardiomyocytes
Neural crest
The ectoderm is the outer layer of the embryo, which gives rise to the external ectoderm and the neuroectoderm. The neuroectoderm can further be divided into the neural crest and the neural tube. The neural crest migrates from the neural tube early in development. While both external ectoderm and the neural tube form an epithelial layer, the neural crest does not and is actually a highly migratory cell lineage. Furthermore, the neural crest is required for innervation of endodermal organs (forming the enteric nervous system), craniofacial features, innervation of the diaphragm for breathing, and many more critical features. Due to its structural and migratory properties, and its importance in development, the neural crest is often referred to as the "fourth germ layer."
Cardiomyocytes refer to cardiac muscle cells, while hepatocytes are liver cells. Beta cells are found in the pancreas and secrete insulin.
Example Question #1 : Gastrulation And Embryonic Germ Layers
Which of the following structures does not arise from the ectoderm?
Nervous system
Lungs
Epidermis
Lens of the eye
Lungs
The ectoderm gives rise to the nervous system, epidermis, lens of the eye, and the inner ear.
The lungs are derived from the endoderm. Most epithelial linings are located toward the superficial regions of the body, and arise from the ectoderm. The linings of the respiratory and digestive tracts, however, are embedded deep within the body and are derived from the endoderm.
Example Question #7 : Gastrulation And Embryonic Germ Layers
Which of the following structures does not arise from the endoderm?
Pancreas
Muscles
Lungs
Liver
Muscles
The endoderm gives rise to most of the internal organs, including the lining of the digestive tract, the liver and pancreas, and the respiratory system.
Muscles and bones are derived from the mesoderm.
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