Question

During the embryonic development, the establishment of polarity along anterior/posterior/dorsal/ventral or medial/lateral axis is called
A. Organiser phenomenon
B. Axis formation
C. Anamorphosis
D. Pattern formation

Answer 1

Hint: The polarity plays an important role in embryo development. The polarity in embryo development can be defined as the tendency of the living organisms to grow and orient in a particular direction.

Complete Answer:
- The polarity in embryos requires movement or shifting of cell fate determinants. This is directed by cytoplasmic movement which is dependent on actomyosin cytoskeleton. Polarity majorly influenced the emergence of the embryonic structures.
- The organiser cells have the ability to instruct fate and morphogenesis of the cells which develop into tissues and organs. These cells have a tendency to orient themselves in a particular direction along the axis. This is called the organiser phenomenon.
- Axis formation: It is the process of formation of an axis. The axis can be ventral/dorsal, medial/lateral.
- Anamorphosis: It is the post embryonic development and moulting in the arthropods.
- Pattern Formation: It is a developmental process by which the cells attain spatial arrangement within an embryo.

Hence, the correct answer is (A).

Note: The development of embryos begins with the zygote which becomes the mass of cells. It then develops into a hollow ball of cells called a blastocyst. In humans, the blastocyst implants in the wall of the uterus. It further develops into an embryo which is attached to the placenta and is surrounded by a membrane which is filled with fluid.