some secretary cells synthesize and release glycoproteins. What is the correct order of the sequence of events as they occur in the secretory cell?
I . Exocytosis
II. Product accumulates in secretory vesicle
III. mRNA binds to ribosomes
IV. Synthesis of glycoprotein

Options

A. III, IV ,I , II
B. III,IV ,II, I
C. IV,III,I,II
D. IV,III,II,I

Answer

To determine the correct order of events that occur in a secretory cell synthesizing and releasing glycoproteins, we can analyze the provided steps:

1. **mRNA binds to ribosomes (Step III)**: The process begins with the binding of mRNA to ribosomes, which is essential for protein synthesis. This is the first step in the translation process where the genetic code is read to produce proteins.

2. **Synthesis of glycoprotein (Step IV)**: Once the mRNA is bound to the ribosomes, the ribosomes translate the mRNA sequence into a polypeptide chain, leading to the synthesis of the glycoprotein. This is the second step in the sequence.

3. **Product accumulates in secretory vesicle (Step II)**: After the glycoprotein is synthesized, it is packaged into secretory vesicles. These vesicles store the glycoproteins until they are ready to be released from the cell.

4. **Exocytosis (Step I)**: Finally, the secretory vesicles fuse with the plasma membrane of the cell, and the glycoproteins are released into the extracellular space through the process of exocytosis.

Thus, the correct order of events is:
**III → IV → II → I**

### Final Order of Steps:
1. **mRNA binds to ribosomes (III)**
2. **Synthesis of glycoprotein (IV)**
3. **Product accumulates in secretory vesicle (II)**
4. **Exocytosis (I)**