Blastula

Gastrula

1. Blastula has a blastocoel.

2. Blastula is produced by the process of blastulation.

3. Blastula undergoes implantation followed by gastrulation.

1. Gastrula has a gastrocoel or archenteron.

2. Gastrula is produced by the process of gastrulation.

3. Gastrula undergoes morphogenesis and then forms germ layers.

Spermatogenesis

Oogenesis

1. Spermatogenesis takes place in testis in mature and fertile males.

2. From one Spermatogonium four haploid sperms are formed during Spermatogenesis.

3. Spermatid developed undergoes metamorphosis in the process of Spermatogenesis.

4. Spermatid development takes place which later becomes a functional sperm.

5. Spermatogonia,primary and secondary spermatocytes and spermatid are the stages of sperms formed during spermatogenesis.

1. Oogenesis takes place in ovaries in mature and fertile females.

2. From one oogonium one haploid ovum and a polar body is formed during oogenesis.

3. There is no such process of metamorphosis in oogenesis

4. Ootid development does not take place during oogenesis. It develops only after fertilization.

5. Oogonia, primary and secondary oocytes are the stages formed during oogenesis. Ootid formation occurs only after fertilization.

Morula

Blastula

1. Morula is the embryonic stage formed after the completion of cleavage.

2. Morula is formed 4 to 6 days after the fertilization.

3. Morula consists of 16 cells.

4. Morula is solid ball of cells.

5. Morula stage is passed in fallopian tube, once it reaches uterus, it starts developing into the next stage.

6. Morula does not have any dis-tinction of its inner cell structure.

1. Blastula is the embryonic stage formed after the completion of blastulation.

2. Blastula is formed  4 to 6 days after the fertilization.

3. Blastula consists of more than 64 cells.

4. Blastula is a hollow ball of cells.

5. Blastula after reaching the uterus is implanted on the wall of uterus.

6. Blastula has a blastocoel, trophoblast and inner cell mass.

Zone pellucida

Corona radiata.

1. Zona pellucida is inner, thin and transparent layer surrounding the secondary oocyte.

2. Zona pellucida is a non – cellular layer.

3. Zona pellucida is secreted by the ovum itself.

4. Zona pellucida is retained for more time after fertilization till the ovum gets implanted in the uterus.

5. Zona pellucida is digested by zona lysine or acrosin at the time of fertilization.

1. Corona radiata is the outer thick layer surrounding the secondary oocyte.

2. Corona radiata is a cellular layer.

3. Corona radiata is formed by follicular cells which are glued together by hyaluronic acid.

4. Corona radiata is retained till the ovum gets fertilized.

5. Corona radiata is digested by hyaluronidase enzyme at the time of fertilization.