Question

Which of the following egg is found in cockroach?

• A. Alecithal
• B. Microlecithal
• C. Centrolecithal
• D. Oligolecithal

Answer 1

The correct option is C Centrolecithal

Many animal eggs contain yolk, a mixture of proteins, phospholipids and fats, that serves as food for the developing embryo. The amount and distribution of yolk vary among different animal groups, depending on the needs of the embryo. Mammalian eggs have very little yolk, because the embryo obtains maternal nutritional support throughout most of its development; whereas the eggs of birds and reptiles must contain sufficient yolk to sustain the embryo until hatching.

An egg in which the yolk is concentrated near the center of the egg cell is called as centrolecithal egg, as is the case in many of the insects like cockroach and others. Most invertebrates and simple chordates have isolecithal eggs with relatively small amounts of yolk uniformly distributed through the cytoplasm. Isolecithal eggs divide completely; this is called as holoblastic cleavage.