Binary fission is a form of asexual reproduction in which a parent organism divides into two identical daughter cells. While binary fission typically occurs without any specific orientation in most organisms, there are some exceptions where it occurs in definite orientation in relation to the cell structures. One such organism is Amoeba.

Amoeba:
Amoeba is a unicellular organism belonging to the phylum Protozoa. It is characterized by its ability to constantly change its shape through the extension of pseudopodia. During binary fission in Amoeba, the process occurs in definite orientation in relation to the cell structures.

Process of Binary Fission in Amoeba:
1. Replication: Before binary fission, the genetic material (DNA) of the parent Amoeba is replicated to ensure that each daughter cell receives a complete set of genetic instructions.

2. Elongation: The parent Amoeba elongates and extends its pseudopodia, creating a constriction point near its center.

3. Nucleus Division: The nucleus of the Amoeba undergoes division to form two identical nuclei, each containing a complete set of DNA.

4. Cytoplasm Division: The cytoplasm of the Amoeba constricts along the constriction point created earlier, eventually leading to the separation of the two daughter cells.

5. Formation of Daughter Cells: Finally, the constriction deepens, and the two daughter cells are fully separated, each containing a nucleus and a portion of the cytoplasm.

Definite Orientation:
In Amoeba, the binary fission occurs in a definite orientation in relation to the cell structures. This means that the constriction point and subsequent division occur across the cell's equator, dividing it into two equal halves. This orientation ensures that each daughter cell receives an equal amount of cytoplasm and organelles, allowing them to function independently. Additionally, the definite orientation helps maintain the overall shape and structure of the Amoeba.

Conclusion:
Amoeba is an organism where binary fission occurs in definite orientation in relation to the cell structures. This orientation ensures the formation of two equal daughter cells with a complete set of genetic material and organelles. By understanding the process of binary fission in Amoeba, we can appreciate the diversity of reproduction mechanisms in different organisms.