Embryology Review Flashcards
During oogenesis there are two meiotic arrests. When is the first?
Diplotene stage of prophase 1
In a mammalian embryos and many other vertebrate embryos, the primordial germ cells are from ___
The yolk sac
What best describes the oogonium in the ovary during the early fetal period
Diploid oogonium with no follicle cells
In meiosis, pairing of homologous chromosomes being during what stage of prophase I?
zygotene
Which of the following refers to the process by which a cell or a part of an embryo becomes restricted to a given developmental pathway? A. Morphogeneis B. Differentiation C. Determination D. Ontogeny
C. Determination
After the first meiotic arrest, the secondary oocyte resumes meiosis at the time of ovulation. What is responsible for shutting down gap junctions?
LH
Capacitation occurs where?
Isthmus of the oviduct
During the transport of the egg through the female tract following ovulation, the most likely site of fertilization is___
Ampulla
what cell type is located outside of the blood-testies barrier
Spermatogonium
What is the principal energy source for ejaculated spermatozoa
Fructose in the seminal vesicle fluid
What cells in males convert testosterone to estrogen?
Sertoli Cells
Rapid transport of the egg through the isthmus of the oviduct requires what hormone?
Progesterone
What is responsible for the production of testosterone in the testes?
Lydig cells or interstitial cells
Endometrial growth thickness is by day 14. Proliferation phase of the uterine cycle is the result of secretion of what hormone by granulose cells?
Estradiol
Progesterone is in charge of the second half
What components of the Graafian follicle form the corpus lutetium? A. Granulose Cells B. Thecal Cells C. Both D. Neither
Both granulose and thecal cells
Inhibin, released by the granulose cells during the ovarian cycle, inhibits secretion of gonadotropins, especially FSH, resulting in ____
Regression of the corpus luteum
During the menstral cycle, a sharp spike in plasma levels of what hormone, just before ovulation, is responsible for ovulation?
LH
Of the barriers to sperm survival and transport within the female reproductive tract, low pH is most important in the what anatomical structure?
The vagina
Base on your knowledge of paralogous groups, which gene would be expressed most anteriorly in the embryo? A. Hoxa-13 B. Hoxc-9 C. Hoxb-1 D. Hoxb-6
C. Hox-b-1
Anterior to posterior depends on the number
The principal inductor in primary neural induction is the A. Hypoblast B. Primitive Streak C. Extraembryoinic mesoderm D. Notochordal Process
D. Notochordal process
Cells of which germ layer are not present in the oropharyngeal membrane? A. Ectoderm B. Mesoderm C. Endoderm D. All are present
B. Mesoderm
Brachyury, a deficiency in caudal tissues in the body is caused by a mutation in what gene? A. Lim-1 B. Noggin C. T D. Sonic Hedgehog E. Activin
C. T
Brachy means tail: Tails starts with T
The hypoblast of the bilaminar early embryo gives rise to which of the following tissue types?
A. Embryonic Endoderm
B. Extraembryoinc Endoderm
C. Both A and B
D. Both Mesoderm and extraembryonic endoderm
B. Extraembryoinc Endoderm
The splitting of the blastocyst during early development resulting in two complete but separate blastocyst within a single trophoblast is the most common mode of twinning. Assuming complete normal identical twins, what developmental property is illustrated?
Regulation
What is thought to be one fo the two signaling molecules that plays a role in the formation of the primitive streak?
TGF-ß
Look up the other one
In what type of signaling results in one dominant cell?
Delta Notch
During the transport of the egg through the female tract following ovulation, the most likely site of fertilization occurs in the____
Ampulla
In mammalian embryos, unlike non-mammalian and invertebrate embryos, most transcription in the embryonic genome, as opposed to the maternal genome, occurs as early as what stage?
4-cell stage
In drosophila, what gene categories are mRNAs derived from the maternal genome rather than the embryonic genome?
Egg-Polarity genes
Which of the following is a transcription factors? A. FGF B. Pax C. TGF D. Notch E. Wnt
B. Pax
Zinc fingers and helix loops are ___
Transcription factors
The principal energy source for ejaculated spermatozoa is
Fructose in the seminal vesicle fluid
What is the most common condition associated with spontaneously aborted embryos?
Chromosomal abnormalities
What tissue from the embryo directly interfaces with the endometrial connective tissue? A. Corona Radiata B. Inner Cell Mass C. Syncytiotrophoblast D. Blastocyst
C. Syncytiotrophoblast
Identical twinning is made possible by what process or property of the early embryo? A. Regulation B. Aneuploidy C. Paternal Imprinting D. Maternal Imprinting E. X-Chromosome Inactivation
A. Regulation
The zona pellucida _____
Prevents premature implantation of the leaving embryo
What form of signaling uses lateral inhibition?
Delta Notch
TGF-ß often utilizes what pathway?
Receptor tyrosin kinase pathway
Mutation of what receptor is the basis for basal carcinomas?
Patched
Transcription of what gene is required to permit cleavage to proceed to the 2-cell stage in mammalian embryos?
4-Oct
Which of the following organizes the border between the dorsal and ventral thalamus? A. Prechordal Plate B. Anterior Neural ridge C. Isthmic Organizer D. Zona Limitans
D. Zona Limitans
In the late primitive streak stage which of the following signal molecules released from the primitive streak activates how genes? A. Noggin B. FGF C. Chordin D. SHH
B. FGF
In meiosis, pairing of homologous chromosomes begins during which of the following stages of prophase I? A. Zygotene B. Leptotene C. Pachytene D. Diplotene
A. zygotene
What best describes the oogonium during the early fetal period?
Diploid with no follicle cells
Inhibin released by the granulose cells during the ovarian cycle, inhibits secretion of gonadotropin, especially FSH, resulting in ____
Regression of the corpus luteum
Which of the following pathways ensures the neural tube closure?
A. Convergent Extension Pathway
B. Planar Cell Polarity Pathway
C. Signaling pathway involving Otx-2 and Gbx-2
D. Anterior neural ridge signaling
B. Planar Cell Polarity Pathway
Which of the following is located at the junction of the midbrain and hindbrain and express FGF-8? A. Prechordal plate B. Anterior neural ridge C. Isthmic Organizer D. Zona Limitans
C. Isthmic Organizer
What best summarizes the effect of grafting a second dorsal lip to the blastocoel of an early amphibian embryo (salamander)?
The dorsal lip can induce the formation of a second embryo
In drosophila, which of the following classes of genes is involved in the deletion of adjacent segments? A. Gap genes B. Pair ruling genes C. Segment polarity genes D. Hox Genes
A. Gap Genes