Question

The egg of placental mammals are

• A. Microlecithal
• B. Alecithal
• C. Mesolecithal
• D. Homolecithal

Answer 1

The correct option is B Alecithal

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. Placental mammals like humans have alecithal eggs.