Question

Each of the following is true about plant rosettes except

A) rosettes are localized in the plasma membrane.
B) rosettes are cellulose-synthesizing enzyme complexes.
C) rosette deposition of cellulose microfibrils is directed by microtubules.
D) rosettes move in the plasma membrane to deposit growing cellulose microfibrils.
E) rosettes deposit cellulose microfibrils only in the middle lamella.

Answer 1

The false statement about plant rosettes is that they deposit cellulose microfibrils only in the middle lamella. Rosettes are responsible for the synthesis and deposition of cellulose in the primary cell wall, guided by microtubules.

Step-by-step explanation:

The statement about plant rosettes that is not true is E) rosettes deposit cellulose microfibrils only in the middle lamella. Plant rosettes are indeed cellulose-synthesizing enzyme complexes that are located in the plasma membrane, and their activity in depositing cellulose microfibrils is directed by microtubules. Additionally, rosettes move within the plasma membrane as they deposit growing cellulose microfibrils.

During the formation of new cell walls in plant cell cytokinesis, the Golgi vesicles coalesce to form a structure called a cell plate, which ultimately merges with existing cell walls and whose formation is guided by microtubules. However, the primary function of rosettes is to synthesize and deposit cellulose microfibrils that make up the plant's primary cell wall, not just the middle lamella, which is a layer rich in pectin's located between primary walls of adjacent cells.