The stage of development that follows cleavage is the
(a) Blastocyst
(b) Morula
(c) Trophoblast
(d) Blastocoele

Verified step by step guidance

1. Step 1: Understand the process of early embryonic development, which begins with fertilization followed by cleavage, a series of rapid mitotic cell divisions.
2. Step 2: Recognize that cleavage results in a solid ball of cells called the morula, which is the immediate stage following cleavage.
3. Step 3: Know that after the morula stage, the embryo develops a fluid-filled cavity called the blastocoele, forming the blastocyst.
4. Step 4: Identify that the trophoblast is a layer of cells forming the outer layer of the blastocyst, important for implantation but not a stage itself.
5. Step 5: Conclude that the stage directly following cleavage is the morula, making option (b) the correct developmental stage after cleavage.

Key Concepts

Cleavage

Cleavage is the initial series of rapid mitotic cell divisions following fertilization, resulting in a multicellular embryo without increasing its overall size. This process partitions the zygote into smaller cells called blastomeres, setting the stage for further embryonic development.

Morula

The morula is the solid ball of cells formed after several rounds of cleavage. It typically consists of 16-32 blastomeres and represents the stage before the embryo develops a fluid-filled cavity, marking a key transition in early embryogenesis.

Blastocyst

The blastocyst is the stage following the morula, characterized by the formation of a fluid-filled cavity called the blastocoele. It has an outer cell layer (trophoblast) and an inner cell mass, which will give rise to the embryo proper, making it crucial for implantation.