What is the Difference Between Blastula and Gastrula?

The blastula and gastrula are two stages in embryonic development that follow the fertilization of an egg. The main differences between these stages are:

1. Cell layers:

• Blastula: A single-layered hollow structure consisting of 128 cells.
• Gastrula: A three-layered, hollow structure composed of two or more germinal layers of cells from which various organs later derive.

1. Cell division:

• Blastula: Results from rapid mitotic cell division.
• Gastrula: Results from slow meiotic cell division.

1. Cell movement:

• Blastula: The cells do not move during the formation of the blastula.
• Gastrula: The cells move through morphogenetic movement during the formation of the gastrula.

1. Germinal layers:

• Blastula: Germinal layers are absent.
• Gastrula: The formation of three germinal layers (ectoderm, endoderm, and mesoderm) occurs.

1. Cell differentiation:

• Blastula: Cells are undifferentiated.
• Gastrula: Cells undergo differentiation.

In summary, the blastula is a single-layered hollow structure with 128 cells, resulting from rapid mitotic cell division, while the gastrula is a three-layered, hollow structure with more cells, composed of germinal layers, and involving slower meiotic cell division. The cells in the gastrula move and differentiate, whereas those in the blastula do not move and are undifferentiated.

Comparative Table: Blastula vs Gastrula

Here is a table comparing the differences between blastula and gastrula:

Blastula and gastrula are two multicellular embryonic stages of animals. The main difference between blastula and gastrula is in their structure and components. Blastula is an early development of an embryo, consisting of a spherical cell layer, while gastrula is an embryo at a later stage, with a hollow cup-shaped structure.