Embryology Practice Questions
19 free Embryology practice questions for the General Science. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Embryology is the branch of biology that studies:
- A The classification of animals
- B Embryonic development of organisms
- C The behavior of animals in the wild
- D The structure of adult organs only
Correct answer: Embryonic development of organisms
Embryology focuses on the development of an organism from the formation of the zygote through various stages until birth or hatching. It examines processes like cleavage, gastrulation, and organ formation. This field helps explain developmental patterns and abnormalities.
The process by which a sperm and ovum fuse is called:
- A Cleavage
- B Fertilization
- C Gastrulation
- D Implantation
Correct answer: Fertilization
Fertilization is the fusion of male and female gametes to form a zygote. This event restores the diploid chromosome number. It marks the beginning of embryonic development.
The zygote undergoes rapid cell divisions known as:
- A Differentiation
- B Cleavage
- C Implantation
- D Organogenesis
Correct answer: Cleavage
Cleavage is a series of rapid mitotic divisions of the zygote without growth in cell size. It produces smaller cells called blastomeres. This stage prepares the embryo for further development.
The solid ball of cells formed after several cleavage divisions is called:
- A Blastula
- B Gastrula
- C Morula
- D Neurula
Correct answer: Morula
The morula is a solid mass of cells formed during early cleavage. It resembles a mulberry in appearance. It later develops into the blastula.
The hollow, fluid-filled stage of early embryonic development is known as:
- A Morula
- B Blastula
- C Gastrula
- D Embryoid
Correct answer: Blastula
The blastula is characterized by a hollow cavity called the blastocoel. It forms after the morula stage. This stage precedes gastrulation.
Gastrulation results in the formation of:
- A Blastomeres only
- B Three germ layers
- C Placenta
- D Extra chromosomes
Correct answer: Three germ layers
Gastrulation reorganizes the blastula into three germ layers: ectoderm, mesoderm, and endoderm. These layers give rise to all tissues and organs. It is a crucial step in embryonic development.
The mesoderm primarily develops into:
- A Lungs and liver
- B Skin and hair
- C Muscles and bone
- D Digestive lining
Correct answer: Muscles and bone
The mesoderm forms structures like muscles, bones, blood vessels, and the circulatory system. It is the middle germ layer. It plays a vital role in forming structural tissues.
The endoderm gives rise to:
- A Brain and spinal cord
- B Muscle tissue
- C Gut and lung linings
- D Epidermis
Correct answer: Gut and lung linings
The endoderm forms the inner lining of the digestive and respiratory systems. It also contributes to organs like the liver and pancreas. It is the innermost germ layer.
The process of formation of organs from germ layers is called:
- A Cleavage
- B Organogenesis
- C Fertilization
- D Metamorphosis
Correct answer: Organogenesis
Organogenesis is the stage during which organs begin to develop from the germ layers. It follows gastrulation. Proper organ formation is essential for healthy development.
In mammals, implantation refers to:
- A Fusion of egg and sperm gametes
- B Blastocyst embeds in the uterus
- C Formation of the placenta
- D Development of embryonic limbs
Correct answer: Blastocyst embeds in the uterus
Implantation occurs when the blastocyst attaches to the lining of the uterus. This allows the embryo to receive nutrients from the mother. It is essential for pregnancy continuation.
Which extraembryonic membrane provides nourishment to the embryo in birds?
- A Amnion
- B Allantois
- C Yolk sac
- D Chorion
Correct answer: Yolk sac
The yolk sac supplies nutrients to the developing embryo in birds and reptiles. It contains stored food in the egg. This membrane supports early development.
The neural tube develops into the:
- A Digestive system
- B Circulatory system
- C Central nervous system
- D Reproductive organ system
Correct answer: Central nervous system
The neural tube forms during neurulation and develops into the brain and spinal cord. It is derived from the ectoderm. Proper closure of the neural tube is critical for normal development.
Which term describes the ability of embryonic cells to develop into any cell type?
- A Totipotency
- B Mutation
- C Meiosis
- D Homeostasis
Correct answer: Totipotency
Totipotent cells can give rise to all cell types, including extraembryonic tissues. The zygote and early blastomeres are totipotent. This ability decreases as development progresses.
Which stage follows the blastula in embryonic development?
- A Morula
- B Gastrula
- C Zygote
- D Embryoid
Correct answer: Gastrula
The gastrula stage follows the blastula. During gastrulation, the embryo forms distinct germ layers. This stage establishes the basic body plan.
The amnion in mammals primarily functions to:
- A Provide oxygen to embryo
- B Store waste
- C Cushion embryo in fluid
- D Produce pregnancy hormones
Correct answer: Cushion embryo in fluid
The amnion forms a fluid-filled sac around the embryo. Amniotic fluid cushions and protects the developing embryo from mechanical shocks. It also maintains a stable environment.
Which scientist is associated with the concept that 'ontogeny recapitulates phylogeny'?
- A Gregor Mendel
- B Charles Darwin
- C Ernst Haeckel
- D Louis Pasteur
Correct answer: Ernst Haeckel
Ernst Haeckel proposed the idea that embryonic development mirrors evolutionary history. Although oversimplified, it influenced early embryological studies. Modern biology recognizes its limitations.
Which process ensures that cells become specialized during development?
- A Differentiation
- B Fertilization
- C Uterine implantation
- D Cleavage division
Correct answer: Differentiation
Differentiation is the process by which cells become specialized in structure and function. It allows the formation of diverse tissues and organs. This process is regulated by gene expression.
In amphibians, metamorphosis is controlled mainly by:
- A Pancreatic insulin
- B Thyroid hormones
- C Adrenaline hormone
- D Ovarian estrogen
Correct answer: Thyroid hormones
Thyroid hormones regulate metamorphosis in amphibians. They trigger the transformation from larval to adult forms. Hormonal control is essential for proper developmental changes.
The placenta in mammals primarily functions to:
- A Digest food items for the embryo
- B Exchange nutrients and waste
- C Produce sperm cells
- D Form the embryonic neural tube
Correct answer: Exchange nutrients and waste
The placenta facilitates the exchange of oxygen, nutrients, and waste between the mother and fetus. It also produces hormones that support pregnancy. This structure is vital for fetal development.