During which stage do the organs of the embryo begin to develop?

• A. Organogenesis
• B. Fertilization
• C. Gastrulation
• D. Cleavage

Answer: (A)

Verified step by step guidance

1. Understand the stages of embryonic development: Fertilization, Cleavage, Gastrulation, and Organogenesis. Each stage has distinct processes and outcomes.
2. Fertilization is the process where the sperm and egg combine to form a zygote. This marks the beginning of development but does not involve organ formation.
3. Cleavage is the rapid division of the zygote into smaller cells called blastomeres. This stage forms a structure called the blastula but does not involve organ development.
4. Gastrulation is the stage where the blastula reorganizes into a three-layered structure (ectoderm, mesoderm, and endoderm). These layers are the precursors to tissues and organs but actual organ formation does not occur here.
5. Organogenesis is the stage where the three germ layers differentiate into specific organs and tissues. This is the stage where the organs of the embryo begin to develop.