Question

Difference between blastula and gastrula?

Answer 1

Blastula:

1. An animal embryo when it is a hollow ball of cells at the early stage of development is referred to as blastula.
2. The zygote proceeds through a few cycles of mitotic divisions before forming a solid ball of cells known as the morula.
3. The cells continue to divide, and eventually a cavity forms within them.
4. This is the blastula stage.

Gastrula:

1. An embryo having two or more germinal layers is referred to as a gastrula.
2. Many of the cells on or near the embryo's surface migrate to a new, more internal place during gastrulation.
3. During gastrulation, the primary germ layers (endoderm, mesoderm, and ectoderm) develop and arrange in their proper positions.

Differences between blastula and gastrula:

Blastula	Gastrula
Blastula occurs in animals.	1.Gastrula is an embryo at the stage following the blastula when it is a hollow-cup-shaped structure having three layers of cells.
2. A single-layered hollow structure.	2. A three-layered, hollow structure.
3. Results from rapid mitotic cell division.	3. Results from slow meiotic cell division.
4. Contains 128 cells.	4. Contains more cells than blastula.