Embryonic development Knowledge-Based Download PDF

Questions

1. 1.

   During early human embryonic development, which transient mesodermal structure provides the essential inductive signals that stimulate the overlying ectoderm to fold and form the neural tube?

   • A) Notochord
   • B) Primitive streak
   • C) Somite
   • D) Allantois
2. 2.

   Which extraembryonic membrane directly encloses the developing human embryo, forming a fluid-filled sac that protects it from mechanical shocks and desiccation?

   • A) Allantois
   • B) Chorion
   • C) Yolk sac
   • D) Amnion
3. 3.

   During the cleavage stage of early human embryonic development, how does rapid mitotic division affect individual cell size and the overall volume of the embryo?

   • A) Individual cell size and total embryonic volume both increase exponentially with each cycle of cell division.
   • B) Individual cell size progressively decreases while the total volume of the embryo remains essentially unchanged.
   • C) Individual cell size remains constant while the total volume of the embryo expands through continuous fluid uptake.
   • D) Individual cell size increases significantly while the total volume of the embryo decreases due to cellular compaction.
4. 4.

   Which structure of the human blastocyst directly mediates implantation into the maternal endometrium and gives rise to the fetal portion of the placenta?

   • A) Inner cell mass
   • B) Zona pellucida
   • C) Epiblast
   • D) Trophoblast
5. 5.

   During early human embryonic development, which process is directly responsible for the rearrangement of cells into the three primary germ layers: ectoderm, mesoderm, and endoderm?

   • A) Cleavage
   • B) Gastrulation
   • C) Neurulation
   • D) Blastulation