Question

Grey crescent band develops in
a. Eye of the frog
b. Fertilised egg of the frog
c. Brain of the rabbit
d. Eye of the cockroach

Answer 1

Hint: All amphibian development depends on cell rearranged interaction during gastrulation. The importance of the grey crescent material. Therefore, lies in its ability to induce gastrulation and other essential changes in production during gastrulation.

Complete answer:
> Option A is incorrect. The eyes of the frog help to force the food down. The eyes located atop the head give frogs a field of view of nearly 180 degrees. This peripheral vision aids them in detecting predators and prey. People and other animals focus on images by altering the lens form.

> Option B is correct. Grey crescent is a grey-colored crescent-like band that forms opposite to the sperm entry point on the amphibian egg surface. It is a surface feature that results in the development of cytoplasmic movements stimulated by the entry of sperm into the egg.

> Option C is incorrect. The brain is divided functionally into three parts. There are brain foreheads, brain halfway through, and brain hinds. Prosencephalon is also called the forebrain, and it is divided into two parts are telencephalon and the diencephalon. Telencephalon has two sections of it. Those are the olfactory lobes and hemispheres of the cerebrum.

> Option D is incorrect. The cockroach eyes are huge, sessile, paired, bean-shaped, and present on both sides of the head. Those are composite. Of compound, the eye is made up of a great number of visual elements called ommatidia. Ommatidium is composed of a reticular (receptor) region and a dioptric region.

So, the correct answer is Option B.

Note: The grey crescent is developed adjacent to the point where the sperm came in. It foretells the animal's future pattern: its ventral and dorsal surfaces; its anterior and posterior surfaces; it's left and right sides. The haploid nuclei of the sperm and the egg unite to form the nucleus of diploid zygotes.