Glossary
| no. | Terms | Definition |
|---|---|---|
| 1 | Mosaic development eg. C.elegans | A kind of embryonic development occurring in the blastocyst. The fertilized ovum undergoes determinate cleavage, developing according to a precise, unalterable plan in which each blastomere has a characteristic position and limited developmental potency and is a precursor of a specific part of the embryo. Damage to or destruction of these cells results in a defective organism |
| 2 | Regulative development eg. mammals | A type of embryonic development in which the fertilized ovum undergoes indeterminate cleavage, producing blastomeres that have similar developmental potencies and are each capable of giving rise to a single embryo. Determination of the particular organs and parts of the embryo occurs during later stages of development and is influenced by inductors and intercellular interaction. Damage or destruction of various cells during the early stages of development results in readjustments and substitutions so that a normal organism is formed | 3 | Nematodes | The nematodes or roundworms constitute the phylum Nematoda. They are a diverse animal phylum inhabiting a broad range of environments. More than helf of them are parasitic in nature eg. C.elegans, rhabditia |
| 4 | Precursor cell | In cell biology, a precursor cell, also called a blast cell or simply blast, is a partially differentiated cell, usually referred to as a unipotent cell that has lost most of its stem cells properties. A precursor cell is also known as a progenitor cell. These cells have multipotency. Precursor cells are known as the intermediate cell before they become differentiated after being a stem cell |
| 5 | Stem cell | Stem cells are undifferentiated biological cells that can differentiate into specialized cells and can divide (through mitosis) to produce more stem cells. They are found in multicellular organisms. |
| 6 | Cell lineage | Cell lineage denotes the developmental history of a tissue or organ from the fertilized embryo. Cell lineage can be studied by marking a cell (with fluorescent molecules or other traceable markers) and following its progeny after cell division. Some organisms as C. elegans have a predetermined pattern of cell progeny and the adult male will always consist of 1031 cells, this is because cell division in C. elegans is genetically determined and known as eutely. This causes the cell lineage and cell fate to be highly correlated. Other organisms, such as humans, have variable lineages and somatic cell numbers. |
| 6 | Lineage tree vs Differentiation tree | A differentiation tree is organized based on tissue or cell size, whereas a lineage tree is organized based on the anterior-posterior position of the cell in the worm's body. Both types of tree denote predictable cell division and differentiation events, however. |
| 7 | Morphogenesis | Morphogenesis (from the Greek morphê shape and genesis creation, literally, "beginning of the shape") is the biological process that causes an organism to develop its shape. It is one of three fundamental aspects of developmental biology along with the control of cell growth and cellular differentiation, unified in evolutionary developmental biology (evo-devo). | 8 | Embryogenesis | Embryogenesis is the process by which the embryo forms and develops. In mammals, the term refers chiefly to early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. Embryogenesis starts with the fertilization of the egg cell (ovum) by a sperm cell, (spermatozoon). Once fertilized, the ovum is referred to as a zygote, a single diploid cell. The zygote undergoes mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of a multicellular embryo. |