Question

The egg of Frog is
A. Centrolecithal
B. Mesolecithal
C. Telolecithal
D. Microlecithal

Answer 1

Hint: The morphology and the anatomy of the egg of a Frog. The Egg of a Frog has a moderate amount of yolk in it. Also, it has a non-uniform distribution of yolk with a greater amount concentrated towards the vegetal pole.

Complete step by step answer:
Centrolecithal –
These eggs are large and elongated in shapes. They have a very large amount of yolk present in them. The nucleus lies at the center of the egg, surrounded by yolk and cytoplasm. Example – Arthropods, Coelenterata
Mesolecithal –
The eggs contain a moderate amount of yolk. Example – Petromyzon, Dipnoi, and Amphibians.
Telolecithal –
These eggs contain moderate to large quantities of yolk. They have a non-uniform distribution of the yolk with greater yolk concentrated towards the vegetal pole. Examples – Fishes, Amphibians, Reptiles, Aves
Microlecithal –
They are also known as Oligolecithal eggs. These are the eggs that contain very little to no amount of yolk present. Example – Tunicates, Amphioxus
The eggs of the frog contain a moderate amount of yolk.
Thus, based on the above information we can conclude that the egg of the frog is Mesolecithal.

Hence, the correct answer is option (B)

Additional Information:
Classification of eggs –
Eggs can be classified into several parameters. We will see the classification based on the amount of Yolk and the distribution of Yolk.
Classification of eggs on the basis of the amount of yolk –
Alecithal Eggs –
The eggs that contain no yolk. Example – Eutherian mammals
Microlecithal Eggs –
They are also known as Oligolecithal eggs. These are the eggs that contain very little to no amount of yolk present. Example – Tunicates, Amphioxus
Mesolecithal Eggs –
The eggs contain a moderate amount of yolk. Example – Petromyzon, Dipnoi, and Amphibians.
Macrolecithal Eggs –
They are also known as Megalecithal or Polylecithal eggs. These eggs contain a large amount of yolk. Example – Prototheria, Reptiles, Birds
Classification of eggs on the basis of the distribution of yolk –
Isolecithal Eggs –
They are also known as Homolecithal eggs. These eggs usually have a very little amount of yolk present. This yolk is uniformly distributed throughout the ooplasm. Example – Amphioxus, Mammals, Echinodermata
Telolecithal Eggs –
These eggs contain moderate to large quantities of yolk. They have a non-uniform distribution of the yolk with greater yolk concentrated towards the vegetal pole. They are further classified as slightly, moderately, and Extremely Telolecithal, depending upon the quantity of yolk in the animal hemisphere. Examples – Fishes, Amphibians, Reptiles, Aves
Centrolecithal Eggs –
These eggs are large and elongated in shapes. They have a very large amount of yolk present in them. The nucleus lies at the center of the egg, surrounded by yolk and cytoplasm. Example – Arthropods, Coelenterata.

Note: The eggs of Frog are mesolecithal. This is because their eggs contain a moderate amount of yolk.