So friends today we talk about of digital marketing and types. This blog very important for you and your future because in this time very needful to this know about it and know how it work. This blog will clear your all doubts and I want only one thing your "Dedication". It is very important for your career without dedication you can't be able for success. Digital marketing is not hard for dedication person because I am also do Digital Marketing for my website and YouTube channel if you have choice to learn Digital Marketing you want also start your hard work. If you like my blog so please comment on my blog because it will motivate me for this work . What is Digital Marketing : Digital marketing is a part of technology, you can do "Branding, Lead Generation, Product Selling, Post Views and many more several fields". Digital marketing give opportunity for your career. What is Digital Marketing - Digital marketing is a social plat
How many stages of Frog Egg Development?
Frog egg development in 6 (six) stages
1. Mount of Unfirtilized Egg
2. Whole mount of Firtilize Egg
3. Whole mount of Blastula
4. Whole mount of Gastrula
5. Whole mount of Neurula 6. Whole mount of Tadpole larva of Frog
• The female frogs deposits it's ova in water.
• The egg is surrounded and covered by three distinct layers which are as follows:
a) the innermost vitelline membrane which is secreted by the egg itself;
b) chorion which forms the intermediate layer and is secreted by follicular cells of the ovary;
c) the outermost; gelatinous, tertiary egg membrane or albumen consisting of 3-4 gelatinous rings which is secreted by the wall of the oviduct.
• The eggs are mesolecithal as they contain in moderate amounts of yolk. The frog egg is also telolecithal as the yolk is concentrated in the vegetal(lower) hemisphere.
• The fertilization of the egg by the entry of the sperm into the egg, results in the formation of zygote.
• The center of the animal and vegetal hemispheres are called the animal and vegetal pole respectively.
• The animal hemisphere contains the diploid nucleus formed by the union of sperm and egg nucleus.
• In the Fertilized egg the vitelline membrane is now called ferti membrane. Soon after fertilization, the egg secretes a protein material which absorbs water and swells up, causing the vitelline membrane to lift up from the zygote.
• The Blastula develops after about the fourth or fifth cleavage and appears in external appearance as a ball of cells. The cells of the Blastula are referred to as blastomeres and are of two different sizes : the smaller, pigmented blastomeres which are located in the animals hemisphere are the micromeres.
• The Blastula is transformed into a Gastrula, which appears externally as a ball of dark pigmented cells, with a circular, light coloured yolky plug formed of larger vegetal cells.
• The size of the Gastrula is still as asmall as the zygote.
• The embryo is called neurula when the two neural plates of the Gastrula join to form a neural tube ( which will form the nervous system of the frog ) along the longitudinal axis.
• Externally the neural tube in the embryo appears as a thickened ridge along the longitudinal axis.
• The eggs of the frog hatch in the water and release free living herbivorous larva.
• The larva measures about 5-7 mm in length.
• The body of the larva is differentiated into a head,. Body proper and a tail with fin.
• Mouth of larva bears horny jaws or teeth.
• Three pairs of external feathery gills can be seen. These act as the functional respiratory organs.
• Tail is long and bears the tail fin on its ventral and dorsal surface.
Thanks and Regards for read my blog nad I hope you got good knowledge of Frog egg development. If you got better knowledge by my blog so please share and support me.
Comments
Post a Comment