Larger subunit of ribosome is dome shaped and attached to ER by :-

Options

A. Ribophorins
B. Amino acid
C. `Ca^(+2)`
D. Hydrogen bonds

Answer

### Step-by-Step Solution:

1. **Understanding Ribosome Structure**: The ribosome consists of two subunits, a larger subunit (60S in eukaryotes) and a smaller subunit (40S in eukaryotes). The larger subunit is dome-shaped.

2. **Role of Endoplasmic Reticulum (ER)**: The endoplasmic reticulum (ER) is a network of membranes involved in protein and lipid synthesis. The rough endoplasmic reticulum (RER) is studded with ribosomes, giving it a "rough" appearance.

3. **Attachment of Ribosomes to ER**: The ribosomes are attached to the rough ER. This attachment is crucial for the synthesis of proteins that are either secreted from the cell or incorporated into the cell's membrane.

4. **Mechanism of Attachment**: The attachment of the ribosome to the rough ER is facilitated by a specific protein known as ribophorin. Ribophorin acts as a receptor that recognizes and binds to the ribosome, allowing the larger subunit to attach to the ER.

5. **Identifying the Correct Answer**: Based on the information, the larger subunit of the ribosome is attached to the endoplasmic reticulum by ribophorin. Therefore, the correct answer to the question is ribophorin.

### Final Answer:
The larger subunit of the ribosome is dome-shaped and is attached to the endoplasmic reticulum by ribophorin.

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