Developmental Biology Exam #2

Dorsal-ventral specification of the neural tube is regulated by secretion of which of the following? A. BMP4/7 from the roof plate (dorsal) / Shh from the notochord (ventral) B. Hox genes from the roof plate (dorsal) / FGF8 from the notochord (ventral) C. Shh from the roof plate (dorsal) / BMP4/7 from the notochord (ventral) D. FGF8 from the roof plate (dorsal) / Hox genes from the notochord (ventral)

A. BMP4/7 from the roof plate (dorsal) / Shh from the notochord (ventral)

A. Cycling, Notch

A. Cycling, Notch B. Axial specification, HOX C. Caudal, SHH D. Determination front, Tbx4 E. gradient, FGF8

Which of the following is a TRUE statement? A. The initial gonad is bipotential, neither male nor female. B. The bipotential gonad is only found in hermaphrodites. C. Sex cords are only found in developing male gonads. D. Sex cords will become the efferent ducts.

A. The initial gonad is bipotential, neither male nor female.

Osteogenesis imperfecta is a disease that results from a genetic mutation that disrupts the formation of ____________ that is required for strength of bone. A. collagen I B. hyaluronan C. hydroxyapatite D. myofibers

A. collagen I

Which of the following tissues is derived from the paraxial mesoderm? A. sclerotome B. anterior visceral endoderm C. rhombomeres D. notochord

A. sclerotome

Which of the following adult structures is derived from somites? A. tendons B. notochord C. cerebellum D. medulla E. pons

A. tendons

Which of the following structures is NOT derived from the epiblast in a human embryo? A. trophoblast B. mesoderm C. ectoderm D. endoderm

A. trophoblast

In the mammalian embryo, which structure is essential to set up the anterior-posterior axis? A.) Anterior visceral endoderm B.) Inner cell mass C.) Node D.) Sperm entry site E.) Primitive streak

A.) Anterior visceral endoderm-CORRECT B.) Inner cell mass-incorrect, this determines the proximal-distal (dorsal-ventral) axis C.) Node-incorrect, this is key to forming left-right asymmetry D.) Sperm entry site-incorrect, this determines the initial axis (animal-vegetal) E.) Primitive streak-incorrect, this forms after the AVE

Which of the following embryonic sources make the largest contribution to the cells currently in your body? A.) Epiblast B.) Extraembryonic mesoderm C.) Hypoblast D.) Trophoblast E.) Amnion

A.) Epiblast

An infection in a developing frog has resulted in the defect [extra limbs on frog]. The infection likely induced expression of __________ and the formation of extra ___________________. A.) FGF8, apical ectodermal ridges B.) FGF8, zones of polarizing activity C.) SHH, zones of polarizing activity D.) WNT7A, dorsal ectoderm

A.) FGF8, apical ectodermal ridges

Key components of the human segmentation clock are gradients and cycling gene expression within the presomitic mesoderm. Gradients of ________________ from the caudal presomitic mesoderm interact with cyclically expressed genes such as ___________________ to regulate somitogenesis. A.) FGF8, lunatic fringe B.) FGF8, Notch C.) retinoic acid, lunatic fringe D.) retinoic acid, Notch

A.) FGF8, lunatic fringe-correct B.) FGF8, Notch-incorrect, while FGF8 is the gradient factor from the caudal presomitic mesoderm, Notch expression itself does not cycle C.) retinoic acid, lunatic fringe-incorrect, retinoic acid is a gradient from the rostral presomitic mesoderm D.) retinoic acid, Notch-incorrect, above about RA and Notch expression itself does not cycle

This individual has one of the most common autosomal recessive genetic diseases in the Puerto Rican population. Vertebral segments are formed but completely FUSED. Which of the following best matches the underlying cause of the vertebral fusion? A.) Faster cycling expression of Notch pathway genes B.) Slower cycling expression of Notch pathway genes C.) Loss of Hox gene expression D.) Mutation in a gene that establishes the determination front

A.) Faster cycling expression of Notch pathway genes-INCORRECT, this would yield smaller vertebrae and caudal agenesis B.) Slower cycling expression of Notch pathway genes-INCORRECT, this would yield longer vertebrae C.) Loss of Hox gene expression-INCORRECT, the identity of the vertebrae would be disrupted D.) Mutation in a gene that establishes the determination front - CORRECT, function of gene gradient and cycling genes at the determination front are required for segmentation

If you treat a developing embryo with a toxin that completely inhibits the formation of neuromuscular junctions you would want to expect myogenesis to be blocked after which of the following stages: A.) Fusion of myoblasts into the primary myotubes B.)Formation of secondary myotubes C.)Segmentation of somites from the presomitic mesoderm D.)Formation of the dermomyotomal compartment E.) Formation of myoblasts form the DML and VLL

A.) Fusion of the myoblasts into the primary tubes.

A 25 year-old woman who is pregnant for the first time undergoes amniocentesis during the 25th week of pregnancy. This testing reveals an increased level of acetylcholinesterase in the amniotic fluid. Acetylcholinesterase is normally produced in the CNS and cannot cross the blood brain barrier. This test suggests which of the following fetal abnormalities? A.) Gastrulation defect B.) Spinal bifida occulta C.) Situs inversus D.) Anencephaly

A.) Gastrulation defect - INCORRECT, the embryo would not survive to 25 weeks without mesoderm formed during gastrulation B.) Spinal bifida occulta-INCORRECT, the spinal cord is not open C.) Situs inversus-INCORRECT, there is reversal of left-right asymmetry in this disorder, not leakage of neural factors into the amniotic fluid D.) Anencephaly-CORRECT, the neural tube is open in the head and exposed to amniotic fluid

An early mouse embryo has its anterior endoderm removed and replaced with posterior endoderm from another embryo. The embryo is cultured and heart development is examined. Which of the following is the most likely outcome of this experiment? A.) No Cardiogenic progenitors will be present B.) There will be septation defects C.) Cardiogenic progenitors will be specified normally D.) Cardiogenic progenitors will be specified at the posterior of the embryo

A.) No Cardiogenic progenitors will be present

Somites form in a ____ sequence. The location of somite formation is dependent upon a gradient of ____ a patterning cue with high levels of expression in the caudal tailed. Fill in the blanks. A.) Rostral to caudal, FGF8 B.) Medial to lateral, RA C.) Dorsal to ventral, Shh D.) Caudal to rostral, Shh E.) Lateral to medial, Wnt1

A.) Rostral to caudal, FGF8

_______ is the morphogen expressed in the _____ that caudalizes/posteriorizes the limb bud. Fill in the blanks with the best answer. A.) SHH, zone polarizing activity B.) WNT7A, dorsal ectoderm C.) FGF8, apical ectodermal ridge D.) FGF8, zone polarizing activity E.) SHH, apical ectodermal ridge

A.) SHH, zone polarizing activity

A developmental biologist has transplanted some forelimb bud mesenchyme underneath the AER of an hindlimb bud mid-way through limb bud outgrowth. Which of the following would you expect to see? A.) There is a wing where you would expect a leg B.) There is a normal leg C.) An appendage that is proximal leg and distal wing D.) An appendage that is proximal wing and distal leg

A.) There is a wing where you would expect a leg INCORRECT, the limb was been specified to be hindlimb/leg B.) There is a normal leg INCORRECT C.) An appendage that is proximal leg and distal wing CORRECT, the proximal regions of this limb will derive from the hindlimb mesenchyme, but the transplanted forelimb mesenchyme will produce forelimb/wing-like structures D.) An appendage that is proximal wing and distal leg INCORRECT, see above

You have employed an induced pluripotent stem approach to reprogram fibroblasts into ES cells. Now you would like to stimulate these cells to generate sensory neurons typically found in the dorsal root ganglia of the peripheral nervous system. Which of the following cues would be most useful for generating these neurons? A.) Wnt1 B.) Folate C.) Nkk2.1 D.) shh E.) Sox2

A.) Wnt1

The vertebrae are formed by resegmentation and fusion of the _________ compartment of a somite and the _________ compartment of the immediately posterior/caudal somite. A.) caudal, rostral B.) caudal, caudal D.) rostral, rostral E.) rostral, caudal

A.) caudal, rostral

During neural development, the dietary vitamin _____ helps prevent _____. Fill in the blanks. A.) folate, neural tube closure defects B.) folate, persistent truncus arteriosus C.) retinoid acid, polydactyly D.) cyclopamine, cleft palate E.) retinoid acid, anencephaly

A.) folate, neural tube closure defects

The somites are derived from which early embryonic tissue? A.) mesoderm B.) endoderm C.) ectoderm D.) neural crest E.) trophoblast

A.) mesoderm

Which of the following abnormalities is a closed neural tube defect caused by a mild disruption in caudal neural tube closure? A.) spina bifida occulta B.) Waardenburg syndrome C.) anencephaly D.) transposition of the great arteries E.) myelomeningocele

A.) spina bifida occulta

Which of the following cell types is formed from epiblast cells that migrate through the primitive streak? A.) Ectoderm B.) Primary hypoblast C.) Mesoderm

A.)Ectoderm INCORRECT, the ectoderm forms from the remaining epiblast that does not migrate through the primitive streak B.) Primary hypoblast INCORRECT, the primary hypoblast forms from islands of cells ventral to the epiblast C.) Mesoderm CORRECT, the mesoderm forms from the epiblast cells migrating through the primitive streak. Remember that the definitive endoderm also forms from migration through the primitive streak.

Carbon monoxide has been demonstrated to disrupt the normal formation of somites. If an embryo is briefly exposed to carbon monoxide during the earliest period of somitogenesis, the formation of several somites can be disrupted. Which of the following vertebrae would be most affected? A. Lumbar (lower back) vertebrae B. Thoracic (chest) vertebrae C. Cervical (neck) vertebrae

A.)Lumbar (lower back) vertebrae INCORRECT B.) Thoracic (chest) vertebrae INCORRECT C.) Cervical (neck) vertebrae CORRECT, somitogenesis produces spinal precursors from the most rostral to the most caudal, so the earliest somites formed will form the cervical vertebrae.

The neural tube is regionalized by developmental gene regulation. Which of the following correctly matches the gene and specified region? A.)Shh - ventralizing the neural tube B.) FGF8 - forebrain-midbrain boundary C.) Hox - dorsal neural tube specification D.) Folate - rhombomere axial specification

A.)Shh - ventralizing the neural tube

B. ~60% female, aromatase

Alligator Mississippiensis eggs were incubated at 32*C until the temperature sensitive period (TSP) and then shifted to 34*C during the TSP. The resulting hatchlings will be ______because the _____ enzyme is more active. A. ~40% male, 5 alpha-reductase B. ~60% female, aromatase C. ~100% female, 21-hydroxylase D. ~100% male, aromatase

A. FGF8, apical ectodermal ridges

An infection in a developing frog has resulted in the defect shown to the right. The infection likely induced expression of ____ and the formation of extra ____. A. FGF8, apical ectodermal ridges B. FGF8, Zones of polarizing activity C. WNT7A, dorsal ectoderm D. WNT7A, Ventral ectoderm E. SHH, Zones of polarizing activity

You work for MegaPharm, a startup pharmaceutical company. Your research shows that you have identified a compound that inhibits osteoclasts. What would you expect if you treated adult mice with this compound? A. Weak, brittle bone B. Dense, heavy bone C. Bone lacking collagen D. Only cartilage and no bone

B. Dense, heavy bone CORRECT, osteoclasts digest bone. If you inhibit this process, the normal process of bone resorption is disrupted and you would end up with dense and heavy bone.

Spondylocostal dysostosis and congenital scoliosis are examples of disruption of which of the following genetic pathways? A. Wnt B. Notch C. Shh D. FGF

B. Notch

The craniofacial músculo-skeletal tissues are primarily derived from a combination of ______ and _______. Fill in the blanks. A.) Cranial Neural Crest, endoderm B.) Cranial Neural Crest, mesoderm C.) Ectoderm, somite derived mesenchyme D.) Trunk neural crest, mesoderm E.) Endoderm, splanchnic mesoderm

B.) Cranial Neural Crest, mesoderm

In a mouse embryo, what event specifies the dorsal-ventral axis in a developing blastocyst? A.) Neurulation B.) Implantatation into the uterine wall C.) Anterior visceral endorphin migration D.) gastrulation E.) nodal vesicular particles transport

B.) Implantation into the uterine wall

Why are craniofacial defects such as cleft palate or cleft lip a signal to physicians to look for more serious defects such as heart abnormalities in newborns? A.) These organs all form at exactly the same time in the embryo. B.) These organs all depend upon a common and important contribution from neural crest. C.) A common defect in gastrulation could be the basis for defects in these organs. D.) Each of these structures is exposed to the amniotic fluid during development.

B.) These organs all depend upon a common and important contribution from neural crest.

If you moved the thigh mesenchyme under the wing ectoderm before limb outgrowth what would the resulting limb be? A.) Wing B.) Thigh C.) Wing/thigh chimera D.) I don't know

B.) Thigh

Which of the following is the most accurate statement regarding the specification of the cardiogenic mesoderm? A.) Wnt signaling in posterior mesoderm induces cardiogenic mesoderm B.) Wnt inhibitors allow BMPs and Fgf8 to specify the cardiogenic mesoderm C.) Shh and Fgf2 signaling induce the cardiogenic mesoderm D.) Noggin inhibits Fgf8 to induce cardiogenic mesoderm along the midline

B.) Wnt inhibitors allow BMPs and Fgf8 to specify the cardiogenic mesoderm

Heart looping ________ . Finish the sentence. A.) results in anterior-posterior polarity being established. B.) converts anterior-posterior polarity to left-right polarity. C.) forms the valves of the heart. D.) is regulated by the endocardial cushions.

B.) converts anterior-posterior polarity to left-right polarity.

Embryonic expression of sex steroid hormones is necessary for normal external genitalia development. Which of the following are the primary sources of these hormones during development? A.) Primordial germ cells B.) sertoli, leydig, and granulosa cells C.) mesonephric cells D.) sex cord cells and mesonephric cells

B.) sertoli, leydig, and granulosa cells

Which side of the blastocoel attaches to the uterus? A. Ventral B. Anterior C. Dorsal D. Caudal

C. Dorsal

In the embryo, the early skeletal muscle originates from the __________. In the adult, skeletal muscle is repaired by fusion of ____________ with muscle fibers. Fill in the blanks. A. ectoderm, hematopoietic stem cells B. sclerotome, neural crest C. myotome, satellite cells D. syndetome, meiotic cells

C. myotome, satellite cells

Boniva (ibandronic acid) is a commonly marketed drug for osteoporosis to increase bone mass. It acts by inhibiting the action of which of the following cells? A. osteocytes B. osteoblasts C. osteoclasts D. chondroblasts

C. osteoclasts

Mesoderm cells at the site of the limb buds respond to beads soaked in fgf8 and grow out along the proximal-distal axis. If beads expressing fgf8 are placed under the epithelium of the back there is no outgrowth. This experiment demonstrates which of the following? A.) Permissive B.) Autocrine signaling C.) Competence D.) Proliferation

C.) Competence

Which of the following terms best describes the process by which myoblasts transform into myofibers? A.) Commitment B.) Specification C.) Differentiation D.) Determination

C.) Differentiation [differentiation is the generation of specialized (often morphologically distinct) cell types from committed precursors]

Atrial and Ventricular septal defects are associated with defects in the development of which tissues? A.) Cardiogenic progenitors B.) Splanchnic mesoderm C.) Endocardial cushions D.) Ventricles

C.) Endocardial cushions

All the cells of the embryo proper (all the cells in your body now) derive from which of the following cells? A.) Hypoblast B.) Trophoblast C.) Epiblast

C.) Epiblast

Your old pet cat has significant decline in hindlimb motor function, likely due to a loss of neurons in the ventral lumbar spinal cord, similar to what occurs in ALS. You collect some cat fibroblasts and dedifferentiate them into ES cells using a standard iPSC induction procedure. To direct differentiation into ventral spinal cord motor neurons for injection into the spinal cord, which of the following combinations would be most appropriate. A.) Low [Shh], high [FGF8] B.) High [Wnt antagonist], high [BMP] C.) High [Shh], high [RA] D.) Low [BMP], high [cyclopamine]

C.) High [Shh], high [RA]

During endchondral ossification, mesenchymal cells will express _______, and _______, and become _______ as they condense to form compact nodules. Choose the correct answer to fill in the blanks. A.) Pax7, myf5, satellite cells B.) Pax1, Sox9, chondrocytes C.) MyoD, Sox9, Osteoblasts D.) Myf5, MyoD, Osteoclasts

C.) MyoD, Sox9, Osteoblasts

Cardiac neural crest migrates into the trunks arteriosus to separate the outflow tract into which of the following two structures? A.) inferior vena cava, superior vena cava B.) left ventricle, right ventricle C.) aorta, pulmonary artery D.) Esophagus trachea E.) ventricles atria

C.) aorta, pulmonary artery

What is an important outcome of heart looping? A.) specification of cardiogenic mesoderm, atria and ventricles B.) establishment of anterior-posterior asymmetry C.) conversion of anterior-posterior asymmetry to left-right symmetry D.) development of the second heart field

C.) conversion of anterior-posterior asymmetry to left-right symmetry

Melanoblasts derive from neural crest that migrate from the ________ along the ________ pathway near the epidermis. A.) notochord, ventral B.) tailed, rostro caudal C.) dorsal neural tube, dorsolateral D.) notochord, lateromedial E.) ventral neural tube, dorsolateral

C.) dorsal neural tube, dorsolateral

Spinal cord motor neurons are derived from which of the following types of embryonic cells? A.) mesoderm B.) neural crest C.) ectoderm D.) endoderm E.) trophoblast

C.) ectoderm

An important cellular process for the formation of myotome and sclerotome is ____ to _____ transition. Choose the best answer. A.) mesenchymal : epithelial B.) endothelial : epithelial C.) epithelial : mesenchymal D.) epiblastic : mesenchymal

C.) epithelial : mesenchymal

In patients with the loss of function mutations in Wnt7a, you would expect to see _______ since WNT7a is not expressed in the developing _______. Fill in the blanks. A.) fingernails on the palmar surface, ventral ectoderm B.) mirror duplication of digits, apical ectodermal ridge C.) loss of finger nails, dorsal limb bud ectoderm D.) loss of finger nails, ventral limb bud ectoderm E.) mirror duplication of digits, zone of polarizing activity

C.) loss of finger nails, dorsal limb bud ectoderm

B

Clicker question

Endochondral ossification produces which of the following outcomes? Conversion of cartilage into bone Continuous division of osteoclasts Loss of bone marrow Opening of the epiphyseal plate

Conversion of cartilage into bone

In the embryo, the early skeletal muscle originates from the __________. In the adult, skeletal muscle is repaired by fusion of ____________ with muscle fibers. Fill in the blanks. A. sclerotome, neural crest B. syndetome, meiotic cells C. ectoderm, hematopoietic stem cells D. myotome, satellite cells

D. myotome, satellite cells

Mesodermal cells at the site of the limb buds respond to beads soaked in FGF8 and grow out along the proximal-distal axis. If beads expressing FGF8 are placed under the epithelium of the back there is no outgrowth. This experiment demonstrates which of the following? A.) Permissive induction B.) Proliferation C.) Autocrine signaling D.) Competence

D.) Competence

In a molecular genetic study, all stillborn fetuses are screened for mutations in Collagen Type II. The result of mutations in this gene leads to a form of achondrogenesis. Which developmental steps are most affected? A.)Formation of myotome B.) Endochondral ossification to turn cartilage into bone. C.) Development of osteoblasts. D.) Development and growth of cartilage.

D.) Development of cartilage from sclerotome CORRECT, Collagen type II is a key structural component of cartilage and disrupted cartilage affects long bone growth. Bone formation is normal.

A developing embryo is treated with a toxin that completely disrupts all neuromuscular junction development. You would expect muscle development in this embryo to be halted at which stage? A.) Formation of myoblasts from the dorsal-medial lip B.) Formation of myoblasts from the ventral-lateral lip C.) Fusion of myoblasts into primary myotubes D.) Formation of secondary myotubes

D.) Formation of secondary myotubes CORRECT. Formation of secondary myotubes requires innervation at the neuromuscular junctions. The previous steps do not required the innervation.

Which of the following is a crucial developmental process that directly contributes to the formation of the mesoderm and endoderm? A.) Capacitation B.) Segmentation C.) Neurulation D.) Gastrulation E.) Septation

D.) Gastrulation

You have surgically removed the anterior endoderm from a one day old chick embryo. It is subsequently cultured and you perform ISH for Mesp1. What do you predict will happen? A.) Mesp1 will show a normal pattern of expression in the cardiac crescent. B.) Mesp1 will be expressed only in the left cardiogenic mesoderm C.) Mesp1 will be expressed in two bilaterally separable hearts D.) Mesp1 will not be expressed

D.) Mesp1 will not be expressed

What is NOT required for the normal segmented organization of the vertebral column? A.) Somite segmentation, followed by resegmentation B.) Fusion of the caudal half of the sclerotome with the posterior sclerotome's rostral half C.) Expression of ephori's in the posterior half of a somite D.) Repulsion of neural crest and axons from the anterior half of a somite E.) Cyclical expression of NOTCH regulators in the presomitic mesoderm

D.) Repulsion of neural crest and axons from the anterior half of a somite

Spondylocostal dystosis is a group of conditions characterized by abnormal development or fusion bones in the spine and ribs. A mutation in which of the following genes would be LEAST likely to cause this problem? A.) Lunatic Fringe (Lngf) B.) Notch1 (Notch1) C.) Delta-3 (Dll3) D.) Sonic Hedgehog (Shh) E.) Hairy Enhancer of split-7 (Hes7)

D.) Sonic Hedgehog (Shh)

During heart development, what is the correct temporal order of events in morphogenesis? A.) Formation of the linear heart tube, specification of lateral plate mesoderm, formation of second heart field, separation, and looping B.) Formation of the second heart field, separation, specification of the cardiogenic mesoderm C.) Specification of the cardiogenic mesoderm, separation, looping, formation of the second heart field D.) Specification of the cardiogenic mesoderm, formation of heart fields, formation of the linear heart tube, looping, and septation

D.) Specification of the cardiogenic mesoderm, formation of heart fields, formation of the linear heart tube, looping, and septation

The neural crest migrates from the __________ neural tube and then into in the skin along the ________ pathway to generate melanocytes. This explains why you have coloration defects as seen in Waardenburg syndrome. A.) ventral, dorsal B.) dorsal, ventral C.) ventral, ventrolateral D.) dorsal, dorsolateral

D.) dorsal, dorsolateral

The neural crest is derived from _______. An important step in neural crest induction is promoter binding to _______. A.) ectoderm, Wnt B.) endoderm, β-catenin C.) mesoderm, Wnt D.) ectoderm, β-catenin

D.) ectoderm, β-catenin

In the diagram to the left the ____ is yellow, the ____ is blue, and the _____ is pink. These germ layers form during ________. A.) ectoderm, mesoderm, endoderm, neurulation B.) endoderm, ectoderm, mesoderm, gastrulation C.) endoderm, mesoderm, ectoderm, neurulation D.) endoderm, ectoderm, mesoderm, gastrulation

D.) endoderm, ectoderm, mesoderm, gastrulation

A. situs inversus

Disruption of the movement of cilia located on the embryonic Node (shown in the EM image at right) is closely linked to which of the following developmental defects? A. situs inversus B. esophago-tracheal fistula C. persistent truncus arteriosis D. anecephaly E. cleft palate

C. Dorsal-medial lip of the dermamyotome, epaxial muscles.

In the diagram above, (B) points to the ____, which develops into the_____. A. Sclerotome, cartilage of the axial skeleton B. Ventral lateral lip of the dermamyotome, epaxial muscles. C. Dorsal-medial lip of the dermamyotome, epaxial muscles. D. Dorsal-medial lip of the dermamyotome, hypaxial muscles. E. Ventral lateral lip of the dermamyotome, hypaxial muscles.

D

In the diagram above, which is the somite compartment that forms the vertebrae and axial skeleton.

A

In the diagram of various hearts below, which one best illustrates an Atrial Septal Defect?

Proprioceptive neurons are particularly dependent upon which trophic factor ligand/receptor combination during development? NGF/TrkA BDNF/TrkB NT3/TrkC NGF/TrkC

NT3/TrkC

A. Migrate randomly through any part of the somite.

Neural Crest migrates specifically through the rostral/anterior half of somites. If you generated a mouse with a knock out of the Ephrin gene, as shown below, you would expect the neural crest to _______. A. Migrate randomly through any part of the somite. B. Avoid the somites and migrate along the neural tube. C. Fail to migrate out of the neural tube D. Migrate specifically through the rostral/anterior part of the somites. E. Migrate specifically through the Caudal posterior part of the somites.

A. a chicken with 4 wings

Scientists have created a transgenic chick embryo that expresses Tbx5 in both the forelimb and the hindlimb bud regions but no Tbx4. What would you expect (1,2) in the resulting chicken? A. a chicken with 4 wings B. a chicken with 1 leg and 2 wings C. a chicken with 1 wing and 2 legs D. a chicken lacking any extremities E. a chicken with 4 legs.

Disruption of the movement of cilia located on the embryonic node is closely linked to which of the following developmental defects? A.)Situs Inversus B.)Esophago-tracheal fistula C.)Persistent truncus arteriosis D.)Anencephaly E.)Cleft palate

Situs inversus

D. SHH, ventral

The experiment shown below demonstrates the effects of _____, which is expressed in the notochord, in specifying the _____ neural tube. A. NOTCH, dorsal B. Retinoic acid, ventral C. FGF8, dorsal D. SHH, ventral E. HOX, ventral

A.) Tbx5

The image on the right shows a mouse embryo that has been labeled using in situ hybridization. RNA probes for which of the following genes would most likely result in the purple staining pattern? A.) Tbx5 B.) FGF8 C.) RALDH2 D.) Pitx2 E.) Shh

C. Primitive streak

The image to the right is of a 24-hour old chick embryo. Cells in the epiblast migrate through the structure delineate by the arrows to form the mesoderm and endoderm. What is the name of this structure? A. Apical ectodermal ridge B. Somites C. Primitive streak D. Anterior Visceral Endoderm E. Zone of polarizing activity

There are specialized cell types that make up the heart. Which of the following best describes their embryonic lineage? They are all derived from ectoderm. They are all derived from endoderm. Each lineage has its own progenitor cell type. They are all derived from cardioprogenitor cells.

They are all derived from cardioprogenitor cells.

rostral-caudal

Which axis is designated by the arrow in this image of the neural tube? rostral-caudal dorsal-ventral left-right

Which cytoskeletal component is found at particularly high concentrations underneath the plasma membrane of an active growth cone. microtubule actin glial fibrillary acidic protein kinetochore

actin

You have removed the zone of polarizing activity (ZPA) from a limb bud. The addition of SHH soaked beads into the area where you removed the ZPA is sufficient to _________ the limb bud. caudalize ventralize dorsalize rostralize

caudalize

Which of the following disorders would results from embryonic exposure to cyclopamine, an inhibitor of SHH signaling? Waardenburg syndrome Anencephaly cyclopia Spinal bifida occulta Dextrocardia

cyclopia

The neural tube is derived which of the following germ layers? endoderm mesoderm ectoderm

ectoderm

The cardiogenic mesoderm arises_________. Finish the sentence. in the splanchnic mesoderm in the blood islands in the ectoderm in the endoderm

in the splanchnic mesoderm

Neuronal number would most likely _____ if caspase-3 was deleted during early development. increase decrease not change grow axons

increase

Lack of the dietary supplement folate can lead to birth defects. Where in the embryo is folate most required for normal development? primitive streak neural folds rhombomeres notochord

neural folds

Which of the following adult structures is derived from somites? pons cerebellum vertebrae notochord medulla

vertebrae