Most abundant substance in all living organism is

Options

A. Micromolecules
B. Macromolecules
C. Cellular pool
D. Water 70.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the most abundant substance in all living organisms. This requires us to consider various substances present in living cells.

2. **Analyzing the Options**: The options provided are:
- A) Micromolecule
- B) Macromolecule
- C) Cellular pool
- D) Water

3. **Defining the Terms**:
- **Micromolecule**: These are small molecules, such as amino acids and nucleotides, that can combine to form larger macromolecules.
- **Macromolecule**: These are larger molecules, including carbohydrates, lipids, proteins, and nucleic acids.
- **Cellular Pool**: This term refers to the total organic and inorganic matter present in a cell.
- **Water**: A simple molecule (H2O) that is essential for life and is found in high quantities in living organisms.

4. **Evaluating Each Option**:
- **Micromolecule**: While important, they are not the most abundant as they are smaller and present in lower quantities compared to water.
- **Macromolecule**: These are larger and essential for life, but they still do not surpass the abundance of water.
- **Cellular Pool**: This is a broader term that encompasses various substances but does not specify a single most abundant substance.
- **Water**: It is known that water constitutes about 70% or more of the total cell mass in living organisms, making it the most abundant substance.

5. **Conclusion**: Based on the analysis, the most abundant substance in all living organisms is **water** (option D).

**Final Answer**: The most abundant substance in all living organisms is **water**.

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