What is meant by determinate and indeterminate cleavage?
Determinate: the developmental fate of each embryonic cell is established very early. Indeterminate: early embryonic cells retain capacity to develop into a complete embryo if isolated from other cells. Cleavage produces blastomeres which are qualitatively equipotential or totipotent.
What type of cleavage do frogs have?
holoblastic
Cleavage in most frog and salamander embryos is radially symmetrical and holoblastic, just like echinoderm cleavage. The amphibian egg, however, contains much more yolk.
What is spiral cleavage in biology?
: holoblastic cleavage that is typical of protostomes and that is characterized by arrangement of the blastomeres of each upper tier over the cell junctions of the next lower tier so that the blastomeres spiral around the pole to pole axis of the embryo — compare radial cleavage.
What is pattern of embryonic cleavage?
Patterns of embryonic cleavage. The pattern of embryonic cleavage particular to a species is determined by two major parameters: the amount and distribution of yolk protein within the cytoplasm, and factors in the egg cytoplasm that influence the angle of the mitotic spindle and the timing of its formation.
What is indeterminate cleavage?
Medical Definition of indeterminate cleavage : cleavage in which all the early divisions produce blastomeres with the potencies of the entire zygote — compare determinate cleavage.
What are the 4 types of cleavage?
Types of cleavage
- Determinate.
- Indeterminate.
- Holoblastic.
- Meroblastic.
What is embryo of frog?
The frog egg is a huge cell; its volume is over 1.6 million times larger than a normal frog cell. During embryonic development, the egg will be converted into a tadpole containing millions of cells but containing the same amount of organic matter. The upper hemisphere of the egg — the animal pole — is dark.
What is animal and vegetal pole?
Animal pole is that region of the ovum where polar bodies are extruded and it receives the sperm while Vegetal pole is that pole which is opposite to the animal pole. Animal poles are the most active part of the protoplasm whereas the vegetal pole is not the most active part of the protoplasm.
What is radial and spiral cleavage?
In radial cleavage, the developing embryo divided right angles to the previous division, resulting in four blastomeres situated directly above four others. In spiral cleavage, the division of cells in the developing embryo occurs in a spiral manner. This is the difference between radial and spiral cleavage.
What is morula stage?
An early stage in post-fertilization development when cells have rapidly mitotically divided to produce a solid mass of cells (16 or more) with a “mulberry” appearance is called the morula stage. The morula stage is the final stage prior to the formation of a fluid-filled cavity called the blastocoel cavity.
Why is cleavage indeterminate?
An embryonic cleavage is said to be indeterminate when it produces cells with a complete set of undisturbed animal or vegetal cytoarchitectural features and when isolated can individually develop into a whole organism.