Introduction to embryology, gametogenesis, fertilization, cleavage , types of implantation

Multiple Choice Questions (MCQs)

1. What is the process of sperm and egg fusion called?
   • A) Cleavage
   • B) Fertilization
   • C) Gametogenesis
   • D) Implantation
     Answer: B) Fertilization
2. Which type of cleavage involves complete division of the egg?
   • A) Meroblastic
   • B) Holoblastic
   • C) Partial
   • D) Unequal
     Answer: B) Holoblastic
3. What is the solid ball of cells formed after cleavage called?
   • A) Blastula
   • B) Morula
   • C) Zygote
   • D) Gastrula
     Answer: B) Morula
4. Which germ layer forms the skin and nervous system?
   • A) Mesoderm
   • B) Endoderm
   • C) Ectoderm
   • D) Trophoblast
     Answer: C) Ectoderm
5. What type of implantation occurs when the embryo embeds itself into the uterine wall?
   • A) Superficial Implantation
   • B) Decidual Implantation
   • C) Interstitial Implantation
   • D) Ectopic Implantation
     Answer: C) Interstitial Implantation
6. Dizygotic twins are also known as:
   • A) Identical twins
   • B) Fraternal twins
   • C) Monozygotic twins
   • D) Embryonic twins
     Answer: B) Fraternal twins
7. What is the primary function of oogenesis?
   • A) Formation of sperm
   • B) Formation of eggs (ova)
   • C) Fertilization of eggs
   • D) Division of zygotes
     Answer: B) Formation of eggs (ova)
8. Which type of egg has minimal yolk and allows for holoblastic cleavage?
   • A) Telolecithal Egg
   • B) Mesolecithal Egg
   • C) Oligolecithal Egg
   • D) Isolecithal Egg
     Answer: C) Oligolecithal Egg
9. The process where three germ layers are formed from the blastula is called:
   • A) Cleavage
   • B) Blastulation
   • C) Gastrulation
   • D) Implantation
     Answer: C) Gastrulation
10. What is the term for a fertilized egg?
    • A) Morula
    • B) Zygote
    • C) Blastocyst
    • D) Embryo
      Answer: B) Zygote

True/False Statements

1. Gametogenesis is the process of producing gametes (sperm and eggs).
   Answer: True
2. Meroblastic cleavage involves complete division of the egg.
   Answer: False (Meroblastic cleavage is partial.)
3. The morula stage consists of a solid ball of cells after cleavage.
   Answer: True
4. Ectopic implantation occurs within the uterus.
   Answer: False (Ectopic implantation occurs outside the uterus.)
5. Monozygotic twins result from two separate fertilized eggs.
   Answer: False (Monozygotic twins come from one fertilized egg.)
6. The ectoderm forms internal organs such as the gut and lungs.
   Answer: False (The endoderm forms internal organs.)
7. Blastulation is the process that transforms a morula into a blastula.
   Answer: True
8. Holoblastic cleavage typically occurs in species with large yolks, like birds.
   Answer: False (Holoblastic cleavage occurs in species with minimal yolk, like mammals.)
9. The trophoblast contributes to placenta formation during development.
   Answer: True
10. Gastrulation leads to the formation of two germ layers only.
    Answer: False (Gastrulation leads to three germ layers.)

Fill in the Blanks

1. The process by which gametes are produced is called __________.
   Answer: gametogenesis
2. The fusion of sperm and egg results in a __________.
   Answer: zygote
3. The __________ is a solid ball of cells formed after cleavage.
   Answer: morula
4. The three germ layers formed during gastrulation are ectoderm, mesoderm, and __________.
   Answer: endoderm
5. __________ implantation occurs when an embryo embeds into the uterine wall.
   Answer: Interstitial
6. Dizygotic twins are also known as __________ twins.
   Answer: fraternal
7. Oligolecithal eggs contain __________ yolk.
   Answer: minimal
8. The __________ stage is characterized by a fluid-filled cavity called the blastocoel.
   Answer: blastula
9. The __________ layer forms skin and nervous tissue.
   Answer: ectoderm
10. Meroblastic cleavage is typical in species with __________ yolks, like birds.
    Answer: large