WebAn egg basically consists of three parts: 1. a shell 2. an egg white 3. an egg yolk. Ex.: An egg from a hen consists of approximately 2/3 egg white and 1/3 egg yolk. The yolk is well-centered in the albumen and is surrounded by the vitelline membrane, which is colorless. The germinal disc, where fertilization takes place, is attached to the yolk. WebApr 6, 2024 · Macrolecithal egg is also named as megalecithal or polylecithal egg. Example: Eggs of insects, birds etc. On the basis of the location of yolk inside the egg, eggs can be classified as-isolecithal, Pelolecithal and centrolecithal egg. (a) Isolecithal egg: When there is uniform distribution of yolk inside the egg it is called isolecithal egg.
Isolecithal yolk embryology Britannica
WebMay 24, 2024 · Mesolecithal egg: There is moderate amount of yolk present in it. e.g. lungfishes, frogs, toads etc. Megalechital or Macrolecithal or Polylecithal egg: They contain huge amount of yolk in them. e.g. sharks, bony fishes, reptiles, birds, insects and prototherians; 2. On the basis of distribution of yolk, eggs are of following types: Web2. Mesolecithal Eggs: They contain moderate amount of yolk, e.g., eggs of lamprey, lung fish, frogs and toads. 3. Macrolecithal (Megalecithal or Polylecithal) Eggs: They contain large … my eyes the pain
Egg: Structure and parts of Hen
WebMesolecithal eggs: Here the Mesolecithal egg yolk is moderate in amount. But the distribution of yolk is distinctly unequal. Macrolecithal or polylecithal eggs: These eggs contain more amount of egg yolk. Functions of yolk in female egg. The egg yolk supplies energy and synthesizes of the products required for elaboration of the embryonic body. Web·*[smʌdʒ]\nn.污点, 脏污, 熏烟\nvt. 弄脏, 使模糊, 用浓烟熏\nvi. 被弄脏 WebThe amount of yolk influences the course of cleavage by the following ways: (1) When heamount of stored yolk increases, the amount of active cytoplasm gradually decreases and the position of nucleus is variously affected. In Teleolecithal eggs (mesolecithal and polylecithal eggs), such displacement of zygotic nucleus from the geometrical centre ... offsen