Question

What is a blastula?——————————

Answer 1

The blastula (from Greek βλαστός (blastos), meaning "sprout") is a hollow sphere of cells, referred to as blastomeres, surrounding an inner fluid-filled cavity called the blastocoele formed during an early stage of embryonic development in animals.

Answer 2

An early stage of embryonic development having a hollow mass of cells.

Step-by-step explanation:

During embryonic development, blastula represents a development stage, characterized by a hollow mass of cells. These cells are known as blastomeres. Inside the ball of cells, a fluid-filled cavity is present, known as segmentation cavity or blastocoel.

In mammals, blastula is called as blastocyst, including humans.