In the name of ALLAH, the most beneficient, the most merciful

Developmental Biology (ZOO501)

Multiple Choice Questions (MCQs)

Objective Questions

  1. Mother provides the fetus with nutrients and oxygen, and the fetus sends its waste products ________ into the maternal circulation.

    1. Carbon dioxide and urea
    2. Carbon monoxide and urea
    3. oxygen and urea
    4. Urea and oxygen
  2. Between the area pellucida and the area opaca is a thin layer of cells called the ________.

    1. Sub germinal cavity
    2. Egg white
    3. Albumin
    4. Marginal belt
  3. The cytotrophoblast initially adheres to the ________ through a series of adhesion molecules.

    1. Endometrium
    2. Ectometrium
    3. Mesometrium
    4. Cytometrium
  4. The cells adjacent to the chorda-mesoderm, the paraxial mesoderm cells, are the presursors of the in ________ fish.

    1. Endodermal somites
    2. Mesodermal somites
    3. Exodermal somites
    4. Somites
  5. In mammalian cleavage at 64-cell stage, the inner cell mass and the ________ cells have become separate cell layers, neither contributing cells to the other group.

    1. Trophoblast
    2. Mesentoblast
    3. Cavitation
    4. Blastocyst
  6. Fishes, ________, and birds undergo discoidal meroblastic cleavage, wherein the early cell division do not cut through the yolk of the egg.

    1. Fishes
    2. Mammales
    3. Amphibia
    4. Reptiles
  7. During mammalian cleavage the trophoblast cells secrete fluid into the morula to create a blastocoels this process called as ________.

    1. Blastocyst
    2. Cavitation
    3. Primitive kit
    4. Primitive groove
  8. A ________ is a cell derived from cleavage in an early embryo.

    1. Blastomere
    2. Ectoderm
    3. Endoderm
    4. Mesoderm
  9. In Nematode cleavage is ________.

    1. Bilateral
    2. Radial
    3. Spiral
    4. Rotational
  10. The narrow connecting stalk of extra-embryonic ________ that links the embryo to the trophoblast eventually forms the vessels of the umbilical cord.

    1. Endoderm
    2. Mesoderm
    3. Ectoderm
    4. Mesentroderm
  11. The first segregation in mammalian cells within the inner cell mass results in the formation of the ________.

    1. Primitive endoderm
    2. Primitive mesoderm
    3. Primitive ectoderm
    4. Primitive kit
  12. Chorion is derived from ________ cells.

    1. hypoblast
    2. epiblast
    3. trophoblast
    4. All of the given
  13. In Tunicate the second Cleavage ________.

    1. Meridional cleavage
    2. Bilateral cleavage
    3. Holoblastic cleavage
    4. Mesentoblastic cleavage
  14. The ________ that are the precursors of the neutral tube invaginate into the embryo and are enclosed by neural folds.

    1. Dorsal Endodermal Cells
    2. Dorsal Mesodermal Cells
    3. Dorsal Ectodermal Cells
    4. Dorsal Endocrine Glands
  15. In Tunicate cleavage during the next three divisions, differences in cell size and shape highlight the ________ of these embryos.

    1. Holoblastic
    2. Meridional
    3. Bilateral Symmetry
    4. Holos symmetry
  16. The peripheral ring of blastodem cells that have not shed their deep cells constitutes the ________.

    1. Area pellucid
    2. Area opaca
    3. Marginal zone
    4. Marginal belt
  17. The cells adjacent to the chordamesoderm, the paraxial ________ cells, are the presursors of the mesodermal somites.

    1. Ectoderm
    2. Mesoderm
    3. Endoderm
    4. Blastoderm
  18. The lateral lips of the blastopore comprise those cells that will become ________.

    1. Parenchyme
    2. Mesenchyme
    3. Photosynthetic parenchyme
    4. Storage Parenchyme
  19. discoidal meroblastic cleavage occur in ________.

    1. amphibians
    2. birds and reptiles
    3. mammals
    4. None of the given
  20. Tunicate gastrulation is characterized by the invagination of the endoderm, the involution of the mesoderm, and the epiboly of the ________.

    1. Endocrine
    2. Ectoderm
    3. Endoderm
    4. Mesoderm
  21. The original type of trophoblast cells constitute a layer called the ________.

    1. Cytotrophoblast
    2. Ectotrophoblast
    3. Mesotrophoblast
    4. Endotrophoblast