Embryology Flashcards
At what stage of meiosis I are oocytes arrested until puberty?
a. Liplotene
b. Diplotene
c. Zygotene
d. None of the above
b. Diplotene
At what stage of meiosis II are oocytes arrested until fertilization?
a. Liplotene
b. Diplotene
c. Zygotene
d. Metaphase
e. Pachytene
d. Metaphase
Which hormone contributes to the proliferation phase of the menstrual cycle?
a. Estradiol
b. Estrogen
c. Progesterone
d. hCG
a. Estradiol; via granulosa cells of the ovarian follicle
Which hormone contributes to the secretory phase of the menstrual cycle?
a. Estradiol
b. Estrogen
c. Progesterone
d. hCG
c. Progesterone; via granulose and thecal cells of ovarian follicle
Which enzyme is one of the major enzymes in the acrosome during fertilization that breakdowns centers b/w the corona radiata cells?
a. Ligase
b. Hyaluronidase
c. Pepsin
d. Fibronectin
e. Acrosin
b. Hyaluronidase
Which enzyme is most important in penetrating the zona pellucida during fertilization, allowing spermatozoa to travel through?
a. Ligase
b. Hyaluronidase
c. Pepsin
d. Fibronectin
e. Acrosin
e. Acrosin
Which of the following transcription factors are examples of homeobox containing genes?
a. Hox and Shh
b. Shh and Pax
c. Pax and Hox
d. RA and Hox
c. Pax and Hox; sequence of highly conserved genes of 180 nts coding for 60 aa
Which signaling molecule is important in the formation of axial structures of the notochord?
a. Hox
b. Pax
c. Shh
d. RA
c. Shh; induces overlying ectoderm to convert to neural ectoderm (TF = Foxa-2, Goosecoid; Signals = Noggin, Chordin)
Primary inductor in primary neural induction
Which signaling molecule is the principal organizer of the isthmic organizer that organizes and polarizes midbrain and cerebellum?
a. Hox
b. Pax
c. FGF-8, Wnt-1
d. Shh
c. FGF-8, Wnt-1
Three signaling centers of the neural tube (isthmic organizer, anterior neural ridge, zona limitans) contain many functions, which one organizes the telenchephalon, parts of diencephalon, olfactory area and the pituitary gland?
a. Isthmic organizer
b. Anterior neural ridge
c. Zona limitans
d. All of the above
b. Anterior neural ridge; Shh and FGF-8
Which of the following signaling centers of the neural tube organizes the border between dorsal and ventral thalamus?
a. Isthmic organizer
b. Anterior neural ridge
c. Zona limitans
d. All of the above
c. Zona limitans; Shh
Which XE tissue is made up of ectoderm and mesoderm tissue?
a. Amnion
b. Yolk sac
c. Chorion
d. Allantois
e. Amnion & Chorion
f. Yolk sac & Allantois
e. Amnion & Chorion
Which XE tissue is made up of endoderm and mesodermal tissue?
a. Amnion
b. Yolk sac
c. Chorion
d. Allantois
e. Amnion & Chorion
f. Yolk sac & Allantois
f. Yolk sac & Allantois
What tissue of the placenta directly interfaces with the maternal uterine connective tissue?
a. Anchoring villi
b. Cytotrophoblast
c. Syncytiotrophoblast
d. Chorion
b. Cytotrophoblast
Which of the following developmental disturbances is due to defective fields?
a. Syndactyly
b. Pelvic kidneys
c. Cleft palate
d. Sirenomelia
d. Sirenomelia
Which of the following developmental disturbances is due to failure of migration?
a. Syndactyly
b. Pelvic kidneys
c. Cleft palate
d. Sirenomelia
b. Pelvic kidneys
Which of the following genes is involved in the development of the vertebral column?
a. Shh
b. Hox
c. Pax
d. FGF
b. Hox
Which of the following is involved in the earliest stage of skeletal muscle tissue development?
a. Myogenic cells
b. Myoblasts
c. Myotubes
d. Muscle fibers
a. Myogenic cells; originate in somites, mitotic cells