What causes menstruation if fertilization does not occur?
A) Rise in estrogen
B) Rise in progesterone
C) Drop in progesterone
D) Increase in LH
📖 شرح: Falling progesterone triggers menstruation.
الإجابة الصحيحة: C
Which hormone stimulates follicle development at the start of the cycle?
A) LH
B) FSH
C) Prolactin
D) Oxytocin
📖 شرح: FSH promotes follicular growth.
الإجابة الصحيحة: B
Where does fertilization typically occur?
A) Isthmus of fallopian tube
B) Ampulla of fallopian tube
C) Uterine cavity
D) Cervical canal
📖 شرح: Fertilization usually occurs in the ampulla.
الإجابة الصحيحة: B
Which structure forms immediately after fertilization?
A) Blastocyst
B) Zygote
C) Morula
D) Embryoblast
📖 شرح: The zygote is the first cell formed after fertilization.
الإجابة الصحيحة: B
What is the stage of the embryo at around 16 cells?
A) Zygote
B) Blastocyst
C) Morula
D) Gastrula
📖 شرح: The morula contains about 16 cells.
الإجابة الصحيحة: C
Which structure implants into the uterine wall?
A) Zygote
B) Morula
C) Blastocyst
D) Primary oocyte
📖 شرح: The blastocyst implants into the endometrium.
الإجابة الصحيحة: C
Which part of the blastocyst forms the embryo?
A) Trophoblast
B) Embryoblast
C) Syncytiotrophoblast
D) Cytotrophoblast
📖 شرح: The embryoblast develops into the embryo.
الإجابة الصحيحة: B
Which hormone is produced by the syncytiotrophoblast after implantation?
A) FSH
B) LH
C) hCG
D) Progesterone
📖 شرح: hCG is secreted by the syncytiotrophoblast.
الإجابة الصحيحة: C
Which structure forms the placenta?
A) Embryoblast only
B) Trophoblast and maternal tissue
C) Morula
D) Zona pellucida
📖 شرح: Placenta forms from trophoblast and maternal endometrium.
الإجابة الصحيحة: B
What prevents polyspermy during fertilization?
A) Zona pellucida thickening
B) LH surge
C) Progesterone release
D) Endometrial shedding
📖 شرح: The zona reaction prevents additional sperm entry.
الإجابة الصحيحة: A
Which cavity forms inside the blastocyst?
A) Amniotic cavity
B) Blastocoel
C) Chorionic cavity
D) Yolk sac
📖 شرح: The blastocoel is the fluid-filled cavity of the blastocyst.
الإجابة الصحيحة: B
Which structure secretes enzymes to allow implantation?
A) Embryoblast
B) Syncytiotrophoblast
C) Morula
D) Zona pellucida
📖 شرح: Syncytiotrophoblast cells invade the endometrium.
الإجابة الصحيحة: B
Which structure forms the fetal portion of the placenta?
A) Decidua basalis
B) Chorionic villi
C) Amniotic membrane
D) Yolk sac
📖 شرح: Chorionic villi form the fetal part of the placenta.
الإجابة الصحيحة: B
Which hormone is produced by the placenta to maintain the corpus luteum early in pregnancy?
A) FSH
B) LH
C) hCG
D) Progesterone
📖 شرح: hCG maintains the corpus luteum.
الإجابة الصحيحة: C
Which layer of the placenta is responsible for nutrient and gas exchange?
A) Syncytiotrophoblast
B) Cytotrophoblast
C) Amnion
D) Decidua capsularis
📖 شرح: The syncytiotrophoblast mediates exchange.
الإجابة الصحيحة: A
Which maternal structure contributes to the placenta?
A) Decidua basalis
B) Decidua capsularis
C) Decidua parietalis
D) Myometrium
📖 شرح: The decidua basalis forms the maternal part of the placenta.
الإجابة الصحيحة: A
Which hormone is produced by the placenta to increase maternal insulin resistance?
A) hCG
B) hPL
C) Progesterone
D) Relaxin
📖 شرح: hPL increases insulin resistance to provide glucose to the fetus.
الإجابة الصحيحة: B
Which structure allows fetal blood to approach maternal blood without mixing?
A) Amniotic cavity
B) Placental barrier
C) Yolk sac
D) Allantois
📖 شرح: The placental barrier separates fetal and maternal blood.
الإجابة الصحيحة: B
Which hormone is primarily responsible for maintaining pregnancy after the first trimester?
A) hCG
B) Progesterone from placenta
C) FSH
D) LH
📖 شرح: Placental progesterone maintains pregnancy later on.
الإجابة الصحيحة: B
Which placental structure increases surface area for exchange?
A) Amniotic membrane
B) Chorionic villi
C) Umbilical cord
D) Decidua parietalis
📖 شرح: Chorionic villi maximize exchange surface area.
الإجابة الصحيحة: B