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

What is a vitelline membrane?

  1. Tertiary egg membrane

  2. Secondary egg membrane

  3. Primary egg membrane

  4. All of these

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It is formed around the plasma membrane of egg secerted by ovum itself.

Multiple choice

Which of the following explains tunica serotina correctly?

  1. It is a part of decidua that lines uterus at a place other than the site of attachment of embryo.

  2. It lies between embryo and lumen of uterus.

  3. It is a part of decidua underlying chronic villi and overlying myometrium.

  4. It is the uterine wall of uterus during pregnancy.

  5. It is decidua reflexa.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tunica serotina also known as Basal deciduas or Decidua basalis is a part of deciduas underlying chorionic villi and overlying myometrium.

Multiple choice

Germinal disc differentiate into two layers. Which of the options names it correctly?

  1. Outer epiblast of larger columnar cells and inner hypoblast of smaller cuboidal cells.

  2. Outer epiblast of larger cuboidal cells and inner hypoblast of smaller columnar cells.

  3. Outer epiblast of smaller cuboidal cells and inner hypoblast of larger columnar cells.

  4. Outer epiblast of smaller columnar cells and inner hypoblast of larger cuboidal cells.

  5. Outer hypoblast and inner epiblast.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cells of inner cell mass or embryonal knob get rearranged to form a flat embryonic disc or germinal disc. The latter differentiate into two layers, outer epiblast of large columnar cells and inner hypoblast of smaller cuboidal cells.

Multiple choice

Which is the source of all the germ layers in the embryo?

  1. The hypoblast

  2. The epiblast

  3. Both hypoblast and epiblast

  4. Osteoblast

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

The first epiblast cell moves inward and displaces the hypoblast to create endoderm. Once endoderm is formed, inwardly moving epiblast forms mesoderm. Cells remaining in the epiblast form ectoderm. Thus, the epiblast is source of all germ layers.

Multiple choice

Ootid is formed as a result of

  1. meiosis-II

  2. meiosis-I

  3. mitosis

  4. amitosis

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Secondary oocyte undergoes meiosis-II to form ootid.

Multiple choice

An example of epiboly is _________.

  1. sea urchin endoderm formation

  2. ambhibian mesoderm formation

  3. sea urchin mesoderm formation

  4. mammalian hypoblast formation

  5. sea urchin ectoderm formation
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Sea urchin ectoderm formed by Epiboly.

Multiple choice

Intrinsic muscles of the tongue are derived from

  1. cervical somites

  2. occipital somites

  3. pharyngeal arch mesoderm

  4. second branchial cleft
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Clear segmentation equivalent to the somites of the trunk is seen only in the paraxial mesoderm of the occipital region, which gives rise to the occipital part of the skull and the extrinsic musculature of the tongue.

Multiple choice

Plerome gives rise to

  1. epidermis

  2. stele

  3. cortex

  4. hypodermis

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

Plerome gives rise to stele and endodermis of a plant.

Multiple choice

Which of the following combinations best describes the characteristic of amphibians in early developmental process?

  1. Mesolecithal eggs, telolecithal eggs and unequal holoblastic cleavage

  2. Microlecithal eggs, telolecithal eggs and discoidal cleavage

  3. Macrolecithal eggs, centrolecithal eggs and unequal holoblastic cleavage

  4. Mesolecithal eggs, meiolecithal eggs and unequal holoblastic cleavage
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Amphibian eggs are mesolecithal (moderate amount of yolk) and telolecithal (yolk concentrated at one pole). They undergo unequal holoblastic cleavage, where the entire egg divides but into unequal-sized cells due to yolk distribution. This contrasts with other egg types in the options.