Question

Diagrammatically differentiate early cleavage of amphibians and mammal​

Answer 1

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• Electric Current is the flow of electrons through a wire solution. In a solid the electrons are passed from one positively charged metallic atom to next but in solution the electron is carried by the ions present in the solution. A solution capable of carrying charge is called an electrolyte.

Answer 2

Answer:

Cleavage in most frog and salamander embryos is radially symmetrical and holoblastic, just like echinoderm cleavage. The amphibian egg, however, contains much more yolk. This yolk, which is concentrated in the vegetal hemisphere, is an impediment to cleavage. Thus, the first division begins at the animal pole and slowly extends down into the vegetal region . In the axolotl salamander, the cleavage furrow extends through the animal hemisphere at a rate close to 1 mm per minute. The cleavage furrow bisects the gray crescent and then slows down to a mere 0.02–0.03 mm per minute as it approaches the vegetal pole (Hara 1977).

The study of amphibian gastrulation is both one of the oldest and one of the newest areas of experimental embryology. Even though amphibian gastrulation has been extensively studied for the past century, most of our theories concerning the mechanisms of these developmental movements have been revised over the past decade. The study of amphibian gastrulation has been complicated by the fact that there is no single way amphibians gastrulate. Different species employ different means toward the same goal (Smith and Malacinski 1983; Minsuk and Keller 1996). In recent years, the most intensive investigations have focused on the frog Xenopus laevis, so we will concentrate on its mode of gastrulation.

Explanation: