Review Questions Flashcards
In craniofacial development, segmentation of the cranial neural tube occurs as a result of expression of which of the following genes?
A. Sox
B. BMP
C. Hox
D. TGF
C. Hox
Shaping of the snout involves the establishment of a gradient between which of the following pairs of signals?
FGF-8 and Shh
Cranial neural crest cells from the region of rhombomeres 6 and 7 are involved in the establishment of which of the following structures?
Pharyngeal arch 3
Numerous experiments have shown that retinoic acid is capable of inducing the formation of the posterior limb in vertebrates. Retinoic acid is not the actual morphogen but is capable of activating which of the following genes, which is thought to express the actual morphogen?
A. Sonic hedgehog gene
B. Wnt-7 gene
C. Pax-3 gene
D. Noggin gene
A. Sonic hedgehog gene
What molecule plays a role in guidance of advancing retinal axons through the optic nerve?
A. Pax-2 B. FGF-3 C. BMP-4 D. Pax-6 E. BMP-7
A. Pax-2
The formation of clubfoot (talipes equinovarus) is associated with which of the following?
A. A misplaced ZPA
B. Defective cellular migration from somites
C. Thalidomide
D. Oligohydramnios
E. A neural crest defect
D. Oligohydramnios
Which of the following factors functions as the initial initiator of future hindlimb development?
A. Hoxd
B. Tbx4
C. Shh
D. Gli3
B. Tbx4
Which of the following statements is TRUE concerning the characteristics of the three stages of kidney development in human embryos?
A. The pronephros is functional only in the first few weeks of human embryonic development; the mesonephros is functional for a short period after that, and the metanephros is functional throughoutout the development of the fetus.
B. The mesonephros is the functional kidney in the human embryo and the pronephric duct is necessary to form the mesonephric duct.
C. The pronephric duct forms the mesonephric duct, and the mesonephric tubules will become associated with the metanephric duct to form the metanephric kidney.
D. The mesonephric duct will become associated with the development of the male reproductive system, and the pronephric duct will become associated with the development of the female Mullerian duct.
B. The mesonephros is the functional kidney in the human embryo and the pronephric duct is necessary to form the mesonephric duct.
Which of the following are NOT derived from neural crest cells?
A. Postganglionic autonomic neurons
B. Autonomic ganglia
C. Sensory neuron cell bodies
D. Motor neuron cell bodies
D. Motor neuron cell bodies
Which of the following factors determine the craniocaudal limits of the early urinary system?
A. Lim-1
B. Hox 4-11 genes
C. Retinoic acid
D. Pax-2 and Pax-8
B. Hox 4-11 genes
Partitioning of the single ventricle into a left and a right chamber begins during which of the following developmental periods?
A. Third week
B. Fourth week
C. Fifth week
D. Seventh week
C. Fifth week
Surface ectoderm is induced to become corneal epithelium by an inductive event originating in which of the following?
A. Optic cup B. Chordamesoderm C. Optic vesicle D. Lens vesicle E. Neural retina
D. Lens vesicle
Which of the following develop from the third pharyngeal pouch in response to high concentrations of Shh?
A. Thyroid
B. Superior parathyroids
C. Thymus
D. Inferior parathyroids
D. Inferior parathyroids
Antagonistic actions of BMP-4 and Shh, along with ventropin, establish which of the following axes?
A. The anterior-posterior axis of the cornea
B. The anterior-posterior axis of the lens
C. The dorsal-ventral axis of the retina
D. The nasal-temporal fields of the retina
C. The dorsal-ventral axis of the retina
Expression of which of the following genes is necessary to prevent pharyngeal arch 2 from differentiating into pharyngeal arch 1?
A. Engrail
B. Pax-7
C. Hoxa-2
D. Foxd
C. Hoxa-2
In most kinds of glandular development signaling between Shh and FGF occurs between the epithelium and mesenchyme. In which of the following development processes does this signaling occur entirely within the epithelium?
A. Nasal
B. Salivary
C. Thyroid
D. Anterior pituitary
B. Salivary
Shaping of the snout involves the establishment of a gradient between which of the following pairs of signals?
A. FGF-8 and Edn-1
B. Hox and Pax
C. TGF-2 and BMP-4
D. FGF-8 and Shh
D. FGF-8 and Shh
In molar development, induction of secondary enamel knots by the primary enamel knot followed by apoptosis of the primary enamel knot is associated with which of the following morphogenetic events?
A. Formation of future molar cusps
B. Induction of the ameloblast layer
C. Induction of the ondontoblast layer
D. Formation of the dental sac
A. Formation of future molar cusps
Trunk neural crest cells utilize three migratory pathways. The earliest (first) emigrating cells follow which of the following pathways?
Ventral path
In a genetic male, mesonephric tubules in the vicinity of the gonad will form which of the following?
A. Rete cords
B. Sex cords
C. Efferent ductules
D. Mesonephric duct
C. Efferent ductules
Pattern formation along the proximodistal axis of the limb bud is primarily determined by which of the following?
A. Paxa gene
B. Hoxd gene
C. Retinoic acid
D. Sonic hedgehog
B. Hoxd gene
Absence of hand-2 results in the absence of which of the following cardiac structures?
A. Left ventricle
B. Right ventricle
C. Left atrium
D. Right atrium
B. Right ventricle
Neural crest-derived cells constitute a significant component of which tissue of the eye?
A. Neural retina B. Lens C. Optic nerve D. Cornea E. None of the above
D. Cornea
Which of the following abnormalities in tooth development is characterized by teeth that appear blue-gray or amber brown and are opalescent and may be caused by mutations in type I collagen?
A. Amelogenesis imperfecta
B. Dentinogenesis imperfecta
C. Enamel fluorosis
D. KGB syndrome
B. Dentinogenesis imperfecta
Which of the following experiments carried out on salamander embryos illustrates that the developing limb is a highly regulative system?
A. Split a limb primordial into two halves and prevent them from fusing
B. Juxtapose two equivalent halves of a limb primordium
C. Remove part of a limb primordium
D. All the above
D. All the above
At which of the following stages of tooth development do both the ameloblast and odontoblast layers first appear together?
A. Tooth bud stage
B. Cap stage
C. Bell stage
D. Dental sac stage
C. Bell stage
Which of the following occurs when an additional limb bud is transplanted into the immediate vicinity of the host forelimb of a salamander embryo?
A. Neither limb bud will be supplied by any branches of the brachial plexus.
B. The brachial nerves will develop branches running out to the additional limb and will supply it.
C. The transplanted limb bud will be supplied by local nerves that would normally supply flank muscles.
D. Local brachial plexus nerves deviate from the normal limb bud and supply only the transplanted limb bud.
B. The brachial nerves will develop branches running out to the additional limb and will supply it.
The ureteric epithelium, influenced by BMP-4, forms which of the following proteins necessary to render the epithelium of the ureter impermeable to water?
A. Sproutys
B. Gremlins
C. Uroplakins
D. Uvomorulins
C. Uroplakins
Hemangioblasts originate from the posterolateral mesoderm during gastrulation and organize into blood islands in the yolk around day 18. They become divided into two lineages. Which of the following factors is responsible for establishing the endothelial lineage?
A. Runx-1
B. Hox 3
C. VEGF-A
D. Angiopoietin
B. Hox 3
Which of the following develops from the cartilaginous portion of the second pharyngeal arch?
A. Meckel’s cartilage
B. Malleus
C. Incus
D. Stapes
D. Stapes
The foramen ovale is a right-left cardiac shunt and is structurally associated with which of the following cardiac structures?
A. Septum primum
B. Septum secundum
C. Foramen primum
D. Foramen secundum
B. Septum secundum
Which of the following neurocristopathies is characterized by pigmentation defects, white stripe in the hair, deafness, and cleft palate among others?
Waardenburg syndrome
The presence of webbing between the toes of wading birds such as ducks and the presence of webbed fingers (syndactyly) is most likely associated with which of the following?
A. Overexpression of Noggin
B. Oligohydramnios
C. Reduced apoptotic activity
D. Amniocentesis
C. Reduced apoptotic activity
What maintains the competence of neural cells to differentiate into autonomic neurons?
A. Shh B. Acetylcholine C. Mash 1 D. Glial growth factor E. TGF-B
C. Mash-1
Metanephrogenic blastemata are induced to condense from the surrounding mesenchyme by which of the following?
A. Allantoic sac
B. Mesonephric duct
C. Pronephric duct
D. Ureteric diverticulum
D. Ureteric diverticulum
The initial formation of the cardiac tube is guided by which of the following?
A. Tbx-2
B. Tbx-5
C. Pax-6
D. Shh
A. Tbx-2