Question

Difference between Animal pole and Vegetal pole.

Answer 1

Hint: The lower end of the embryo is called vegetal pole whereas the pole which is opposite to the vegetal pole is called animal pole and rapid division is seen in animal pole.

Complete answer:
Animal pole is that region of the ovum where polar bodies are extruded and it receives the sperm while Vegetal pole is that pole which is opposite to the animal pole.
There is presence of small cells which divide rapidly in the animal pole in contrast with the vegetal pole below it whereas there is presence of large yolky cells which divide very slowly in the vegetal pole in contrast with the animal pole above it.
The animal pole is thought to be differentiated into the later embryo by itself in some cases whilst in some cases, the vegetal pole is thought to be differentiated into the extra embryonic membranes which protect and nourish the developing embryo, for instance, placenta in mammals and the chorion in birds.
Animal poles are the most active part of the protoplasm whereas the vegetal pole is not the most active part of the protoplasm.
Vegetal pole divides slowly but it divides into larger blastomeres whereas animal pole divides rapidly but there is formation of smaller blastomere as compared to the vegetal pole.
At animal poles, the cytoplasm appears to be more active whereas cytoplasm is less active at the vegetal pole.
Nucleus is present at the animal pole whereas there is presence of most of the yolk in the vegetal pole.
The animal pole is heavily pigmented whereas the vegetal pole is unpigmented.

Note:
That region of the ovum where polar bodies extrudes and receives the sperm is known as animal pole whereas the pole which is present at the opposite of animal pole is termed as vegetal pole and in both the cases, there is difference in the division as in animal pole, there is presence of small cells which divides rapidly but in vegetal pole, yolk cells divides slowly.