blastodisc
Học thuậtThân thiện
Definition
Noun: 1. A layer of cells on the inside of the blastula: In embryology, the blastodisc is a disc-shaped layer of cells found on the surface of the yolk in the eggs of birds, reptiles, and some fish. It is the region where the embryo begins to develop from a single layer of cells.
Usage
The term "blastodisc" is used specifically in the context of developmental biology and embryology to describe an early embryonic structure. - It is the site of early cell division and differentiation. - It is a key structure in meroblastic cleavage, where only part of the egg divides.
Examples
- Under the microscope, the blastodisc was clearly visible as a small, circular area on the yolk.
- The formation of the blastodisc marks the beginning of embryonic development in avian species.
- Researchers studied the gene expression patterns within the blastodisc.
Advanced Usage
- Blastodisc vs. Blastoderm: While closely related, a typically refers to the initial single layer of cells. After further cell division, it often becomes a multi-layered structure called a .
- Developmental Significance: The cells of the blastodisc give rise to all the tissues and organs of the embryo.
Variants and Related Words
- Blastoderm (noun): A later stage where the blastodisc becomes a multi-layered sheet of cells.
- Blastula (noun): An early embryonic stage, a hollow ball of cells, of which the blastodisc is a part in certain egg types.
- Embryonic disc (noun): A synonymous term sometimes used, especially when referring to the equivalent structure in mammalian development.
Synonyms
- Germinal disc
- Embryonic disc (in specific contexts)
Notes
- The term is highly technical and is primarily used in scientific literature and academic discussions.
- It is not typically used in everyday language or in non-scientific contexts.
Noun
- a layer of cells on the inside of the blastula