blastomere

References

Videos

See time-lapse microphotography of blastomeres created by mitotic cleavage of embryonic cells

blastomere

biology

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 22, 2026

Quick Summary

See time-lapse microphotography of blastomeres created by mitotic cleavage of embryonic cells — See time-lapse microphotography of blastomeres created by mitotic cleavage of embryonic cells Learn about mitotic cleavage of embryonic cells by watching this time-lapse microphotography of the process.

A blastomere is one of the cells produced during the early stages of embryonic development, specifically through the process of cleavage. After a fertilized egg (zygote) undergoes repeated cell divisions, these resulting cells are called blastomeres. These blastomeres then form a hollow sphere of cells known as a blastula, which is an early stage of embryonic development. In mammals, this blastula stage is called a blastocyst.1234

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

4 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

animal development
Cleavage
…produced during cleavage are called blastomeres. The divisions are mitotic—i.e., each chromosome in the nucleus splits into two daughter chromosomes, so that the two daughter blastomeres retain the diploid number of chromosomes. During cleavage, almost no growth occurs between consecutive divisions, and the total volume of living matter does not…
Read More
…produced during cleavage are called blastomeres. The divisions are mitotic—i.e., each chromosome in the nucleus splits into two daughter chromosomes, so that the two daughter blastomeres retain the diploid number of chromosomes. During cleavage, almost no growth occurs between consecutive divisions, and the total volume of living matter does not…
Read More

cleavage
…divisions produce separate cells called blastomeres. The first few cleavages occur simultaneously in all of the blastomeres (cells), but, as the number of cells increases, simultaneity is lost, and the blastomeres divide independently. Little growth occurs between divisions. Even after several divisions, the group of blastomeres is about the same…
Read More
…divisions produce separate cells called blastomeres. The first few cleavages occur simultaneously in all of the blastomeres (cells), but, as the number of cells increases, simultaneity is lost, and the blastomeres divide independently. Little growth occurs between divisions. Even after several divisions, the group of blastomeres is about the same…
Read More

morula
blastomeres resulting from a number of cleavages of a zygote, or fertilized egg. Its name derives from its resemblance to a mulberry (Latin: morum). A morula is usually produced in those species the eggs of which contain little yolk and, consequently, undergo complete cleavage. Those…
Read More
blastomeres resulting from a number of cleavages of a zygote, or fertilized egg. Its name derives from its resemblance to a mulberry (Latin: morum). A morula is usually produced in those species the eggs of which contain little yolk and, consequently, undergo complete cleavage. Those…
Read More

prenatal development
Cleavage and blastulation
Each blastomere receives the full complement of paternal and maternal chromosomes.
Read More
Each blastomere receives the full complement of paternal and maternal chromosomes.
Read More

cell
The process of differentiation
…that produce separate cells called blastomeres. Each blastomere inherits a certain region of the original egg cytoplasm, which may contain one or more regulatory substances called cytoplasmic determinants. When the embryo has become a solid mass of blastomeres (called a morula), it generally consists of two or more differently committed…
Read More
…that produce separate cells called blastomeres. Each blastomere inherits a certain region of the original egg cytoplasm, which may contain one or more regulatory substances called cytoplasmic determinants. When the embryo has become a solid mass of blastomeres (called a morula), it generally consists of two or more differently committed…
Read More

zygote
These smaller cells, called blastomeres, are suitable as early building units for the future organism.
Read More
These smaller cells, called blastomeres, are suitable as early building units for the future organism.
Read More