Endosperm polyembryony is a type of true polyembryony in which multiple embryos develop from the endosperm of a single fertilized ovule. This phenomenon is commonly observed in citrus fruits and some other plant species.

Explanation:
Endosperm polyembryony is a type of polyembryony in which multiple embryos develop from the endosperm of a single fertilized ovule. This phenomenon is commonly observed in citrus fruits and some other plant species. In endosperm polyembryony, the zygote divides to form two or more embryos, which are genetically identical.

Advantages of Endosperm Polyembryony:
1. Increases the chances of successful germination and survival of the seedlings.
2. Provides a mechanism for vegetative propagation, as multiple plantlets can be produced from a single seed.

Disadvantages of Endosperm Polyembryony:
1. Competition between the multiple embryos for resources in the endosperm can lead to reduced growth and development of the individual embryos.
2. The genetic uniformity of the multiple embryos can limit the genetic diversity of the offspring.

Conclusion:
Endosperm polyembryony is a type of true polyembryony that is observed in some plant species. While it provides advantages in terms of increased chances of successful germination and vegetative propagation, it can also have disadvantages such as competition between the embryos and limited genetic diversity.