Middle lamella of cell wall is mainly made up of 

The middle lamella is the layer that forms the boundary between adjacent plant cells. It acts as a "glue" to hold the cells together. The main component of the middle lamella is calcium pectate (Ca-pectate).

Explanation:

1. Magnesium pectate (Mg-pectate): This is not the primary component of the middle lamella, though magnesium can play a role in plant cell structure.
2. Cellulose: Cellulose is a major component of the plant cell wall but is not the primary component of the middle lamella.
3. Calcium pectate (Ca-pectate): The middle lamella is primarily made of calcium pectate, which is a complex of pectin and calcium. It helps in binding the cells together.
4. Hemicellulose: This is a component of the cell wall but is not the main substance in the middle lamella.

Conclusion:

The correct answer is c) Ca-pectate, as it is the main component responsible for the structure of the middle lamella in plant cells.