 development, protostorm versus deuterostorms, first the contents, protostorms, deuterostorms, cleavage pattern in protostorms and deuterostorms, and the determinate and the indeterminate cleavage. So first the protostorms, so let me discuss the whole animal kingdom, I will talk about all the animals, normally the animals they are divided into two major groups, the first one is the grade radiata, and the other one is the grade bilateria, we divide the animal kingdom into two major groups, one group is called grade, the other group is called radial symmetry, and the other group of animal kingdom which are having bilaterals symmetry, they are actually the grade bilateria, so grade bilateria is the larger one, we have a file like the sealant rates, in which the diploplastic and radial symmetry are placed, that grade radiata will come, but most of the animal file they are included in grade bilateria, so grade bilateria has more animals, grade bilateria is divided into two major groups, one is the protostorms, and the other one is the deuterostorms, so the protostorms they belong to group protostomia, and deuterostorms they belong to deuterostomia group, so first we are having the protostorms, so protostorms, if we look at the word, there are two words actually protomin, first and storm in mouth, so actually protostorm is the group of animal in which the blastopore which is formed during gas pollution is transformed into the mouth, this means when we convert to the mouth we give the name of protostorms, in protostorms in the animal file there are triple blasted animals, whether they are acelomates, cedocelomates and some celomates, now in this represented file there are the platyhelminthes, platyhelminthes acelomates, similarly acelomates they are cedocelomates, then the nematodes and anelids and the mollusks, so these are the major representative file of the protostorms, deuterostorms, deuterostorms are the animals in which the blastopore is actually developed into anus while mouth is developed from some secondary position, that is why deuterostorm is a group in which during development the blastopore is not converted into a mouth, it is converted into a mouth rather than a second position, that is why they are called as deuterostorms, so deuterostorms are also the important group of the grade bilateria, grade bilateria that if the representative file of deuterostorms are actually the three representative file of deuterostorms, number one is the akinodermata, then hemicordata and the chordates, so these are the three representative file of the, so overall if we look at the top three phylum, we will get grade deuterostorms of the group deuterostorms, whereas the three above are all included in the protostorms, the triple blasts are starting from platyhermethase, so from platyhermethase, the akinodermata, the phylum that they are actually the protostorms, so what is the difference between the protostorms and the deuterostorms, the major differences between the two are present in the developmental stages, what are the differences between the protostorms and the deuterostorms, the first difference between the protostorm and deuterostorm is the difference in the cleavage pattern, the cell division pattern has a little difference in the case, in the protostorms the cleavage is the spiral, spiral cleavage means that a helical pharma cell will range from one another, exactly the cell will not come on top of each other, this means that the lower tire of the cell and the upper tire of the cell will not be exactly on top of each other, in fact, the cell will come up a little tilted, so why this tilting is there, why this spiral cleavage is there, the basic reason is due to the orientation of spindle fibres, the spindle fibres in protostorms they are actually arranged in the oblique pattern to the animal vegetal portion, if this animal vegetal portion is there or pole is there, then the cells will not divide from top to bottom, but will divide on the oblique side and tilted side, due to aerostorms they are having radial cleavage, the radial cleavage in detero stream means that the lower tire of the cell is present exactly below the upper tire of the cells, so the upper tire of the cells and the natural tire of the cells are in the same line, on one line they are present and basically this is due to the presence of mitotic apparatus or mitotic spindle perpendicular to the animal and the vegetal pole, when the animal and the vegetal pole are in the same line and the spindle fibres are also present on that line, then the cells will do exactly what they will do, when they will divide on each other, in this tilt it will not happen, here in this diagram, in the upper diagram you can see that these are differed deuterostorms, in deuterostorms you can see that the lower tire of the cells and the upper tire of the cells are exactly on each other, so this is the pattern of cleavage in the deuterostorms and overall this pattern of cleavage is called the radial cleavage, this is called radial cleavage, on the lower side of the cells they are the spiral cleavage, in spiral cleavage and radial cleavage the major difference is this is about the orientation of upper and lower tires of cells, if you see in this, if this is a cell then the cell above it is totally tilted on one side, exactly above it is not present, so the other difference between protostorm and deuterostorm is the determinate and indeterminate cleavage, when the protostorms are present on the two cell stage or four cell stage then the cell's fate is confirmed and if those cells are removed from the embryo, the relevant organ will not be formed, whereas in deuterostorms the cell's fate in deuterostorms is determined by the later embryonic stages so if cells are removed in deuterostorms then no body organ will be missing in fact all the body organs are formed