To determine how many of the listed properties are defining characteristics of living organisms, we will analyze each property: growth, reproduction, metabolism, cellular organization, and consciousness.
### Step-by-Step Solution:
1. **Growth**:
- Growth refers to an increase in size or mass, which can occur in both living and non-living entities (e.g., accumulation of sand). Therefore, growth is not a defining characteristic of living organisms.
2. **Reproduction**:
- Reproduction is the ability to produce new individuals. While most living organisms can reproduce, there are exceptions (e.g., sterile organisms). Thus, reproduction is not universally applicable to all living organisms and is not a defining characteristic.
3. **Metabolism**:
- Metabolism encompasses all biochemical processes that occur within a living organism, including energy production and utilization. This process is unique to living organisms and is essential for their survival. Therefore, metabolism is a defining characteristic of living organisms.
4. **Cellular Organization**:
- All living organisms are composed of cells, which are the basic units of life. Non-living things do not have cellular organization. Hence, cellular organization is a defining characteristic of living organisms.
5. **Consciousness**:
- Consciousness refers to the awareness of oneself and the environment. While many organisms exhibit some level of consciousness or responsiveness to their environment, it is not universally applicable to all living organisms (e.g., plants do not exhibit consciousness in the same way animals do). Therefore, consciousness is not considered a defining characteristic of all living organisms.
### Conclusion:
Based on the analysis, the defining characteristics of living organisms from the given properties are:
- Metabolism
- Cellular Organization
Thus, the total number of defining characteristics of living organisms from the list is **2**.
### Final Answer:
The answer is **2**.
