Biology

Embryonic Development

621 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 the name given to a fertilised egg?

  1. Embryo

  2. Foetus

  3. Zygote

  4. Placenta
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The sperms enter through the vaginal passage during sexual intercourse. They travel upwards and reach the oviduct where they may encounter the egg. The fertilised egg, i.e. the zygote, gets implanted in the lining of the uterus.

Multiple choice

Regeneration of liver is

  1. metamorphosis

  2. repairative metamorphosis

  3. epimorphosis

  4. morphogenesis

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

In this type of metamorphosis, changes are made by the repair process. This happens during regeneration of liver.

Multiple choice

Which of the following layers develop(s) first during embryonic development?

  1. Ectoderm

  2. Mesoderm

  3. Endoderm

  4. Both 2 and 3

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

The germ layers develop early in embryonic life, through the process of gastrulation. During gastrulation, a hollow cluster of cells reorganises into two primary germ layers: an inner layer called endoderm and an outer layer called ectoderm. Endoderm being the inner layer, develops firstly.

Multiple choice

Layers of an ovum from outside to inside are

  1. corona radiata, zona pellucida and vitelline membrane

  2. zona pellucida, corona radiata and vitelline membrane

  3. vitelline membrane, zona pellucida and corona radiata

  4. zona pellucida, vitelline membrane and corona radiata

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

Correct Answer: corona radiata, zona pellucida and vitelline membrane

Multiple choice

Liver and pancreas are derivatives of

  1. ectoderm

  2. endoderm

  3. ectoderm and mesoderm

  4. ectoderm and endoderm

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

Endoderm forms the stomach, colon, liver, pancreas and urinary bladder.

Multiple choice

Choose the correct statement with reference to Ascaris.

  1. Hatching of embryos takes place in the stomach due to lytic enzyme.

  2. Inside the body of host, adulthood is reached in 10 day time.

  3. Development of moulting takes place in the alveoli of lungs.

  4. Hatching of embryos takes place within 10 hours.

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

After infective eggs are swallowed, the larvae hatch, invade the intestinal mucosa and are carried to the lungs. The larvae mature further in the lungs (10 - 14 days), penetrate the alveolar walls, ascend the bronchial tree to the throat and are swallowed.

Multiple choice

Pseudocoelom develops from

  1. embryonic mesoderm

  2. archenteron

  3. blastocoel

  4. blastopore lip
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pseudocoelom is a body cavity derived from the blastocoel.

Multiple choice

Which of the following statements is incorrect?

  1. An embryo with 8 to 16 blastomeres is called a morula.

  2. A morula continues to divide and transforms into blastocyst.

  3. The size of each cell of a morula is equal to a zygote.

  4. Blastocyst has a fluid-filled cavity.

  5. An inner group of cells attached to trophoblast is called the inner cell mass.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The morula, a collection of around 30 cells (blastomere), is created at about 96 hours. Because these cells arise only through the cleavage of the zygote and all are found inside the pellucid zone, which cannot expand, no growth is seen. Every new cell is thus only half as large as the cell from which it derives.