Biology

Embryonic Development

572 Questions

Embryonic development questions cover the biological processes of gamete fusion, germ layer formation, and fetal maturation. The focus lies in identifying extraembryonic structures, trophoblast functions, and sequential developmental stages. This specialized topic appears regularly in biology screening tests and medical entrance examinations.

Germ layer formationBlastocyst implantationExtraembryonic structuresFetal development stagesReproductive physiology

Embryonic Development Questions

Multiple choice

Which of the following statements about superficial cleavage is correct?

Cleavage is the process of rapid, successive mitotic division of zygote into large cells within a period extending from fertilization to blastula or beginning of gastrulation. All divisions in cleavage are mitotic in nature with the rate of cleavage depending on species & temperature. Early cleavage is synchronous but a late cleavage of the cell division is asynchronous.

  1. It is the cleavage is restricted in active cytoplasm of animal pole.

  2. It occurs in micro or isolecithal eggs resulting blastomere are approximately of equal size.

  3. The cleavage remains restricted to the periphery cytoplasmic region.

  4. It is the process of rapid, successive mitotic division of zygote into large cells.

  5. The cleavage produces unequal size blastomere including micromeres and macromere due to polarization of yolk holoblastic.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In centrolecithal eggs the cleavage remains restricted to the periphery cytoplasmic region,  which is called superficial cleavage. E.g, Arthropods, mainly insects.

Multiple choice

What is unequal holoblastic cleavage?

Cleavage is the process of rapid, successive mitotic division of zygote into large cells within a period extending from fertilization to blastula or beginning of gastrulation. All divisions in cleavage are mitotic in nature with the rate of cleavage depending on species & temperature. Early cleavage is synchronous but a late cleavage of the cell division is asynchronous.

  1. It is the cleavage remains restricted to the periphery cytoplasmic region.

  2. It is the process of rapid, successive mitotic division of zygote into large cells.

  3. It is the type of cleavage, which is restricted in active cytoplasm of animal pole.

  4. It is the type of cleavage in mesolecithal and telolecithal eggs.

  5. It occurs into micro or isolecithal eggs resulting blastomere are approximately of equal size.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In mesolecithal and telolecithal eggs due to polarization of yolk holoblastic cleavage produces unequal size blastomere including micromeres [small size blastomere] and macromere [large size] is called unequal holoblastic cleavage. E.g, lower fishes and amphibians.

Multiple choice

Which is the future alimentary canal?

  1. Blastopore

  2. Archenteron

  3. Delamination

  4. Epiboly

  5. Involution
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Archenteron is the cavity, which occurs inside gastrula and is the future alimentary canal. It opens to the outside through blastopore, which later on closes.

Multiple choice

Allantois consists of ___________.

  1. mesoderm inside and ectoderm outside

  2. mesoderm outside and ectoderm inside

  3. mesoderm inside and endoderm outside

  4. mesoderm outside and endoderm inside

  5. ectoderm outside and endoderm inside
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Allantois consists of mesoderm on outside and endoderm internally.