Cell membrane carbohydrates participate in :

Options

A. cell adhesions
B. cell-to-cell recognition
C. transporting substances across the membrane
D. hydrophilic attractions

Explanation

**Step-by-Step Solution:**

1. **Understanding Cell Membrane Carbohydrates:**
- Cell membrane carbohydrates are often found attached to lipids (forming glycolipids) and proteins (forming glycoproteins) in the cell membrane.

2. **Functions of Cell Membrane Carbohydrates:**
- These carbohydrates play a crucial role in various cellular functions. Primarily, they are involved in cell recognition and adhesion.

3. **Analyzing the Options:**
- **Option 1: Cell additions** - This could refer to how cells stick together, which is a function of carbohydrates.
- **Option 2: Cell to cell recombination** - This relates to how cells recognize each other and can communicate or adhere, which is also a function of carbohydrates.
- **Option 3: Transporting substances across the membrane** - This is primarily the role of proteins, not carbohydrates.
- **Option 4: Hydrophilic attractions** - This is more related to the properties of proteins and their interactions with water, rather than carbohydrates.

4. **Identifying the Correct Functions:**
- From the analysis, we can conclude that carbohydrates in the cell membrane participate in:
- Adhering cells together (cell additions).
- Recognizing cells (cell to cell recombination).

5. **Conclusion:**
- The correct answers for the participation of cell membrane carbohydrates are options related to cell adhesion and cell recognition, which are options 1 and 2. Thus, the best answer to the question is that cell membrane carbohydrates participate in cell to cell recognition.

**Final Answer:**
Cell membrane carbohydrates participate in cell additions and cell to cell recombination.

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