Which one of the following constitutes the two best reasons for distinguishing the living from the non living?

Options

A. Growth and locomotion
B. Irritability and locomotion
C. Respiration and excretion
D. Reproduction and locomotion

Answer

To determine the two best reasons for distinguishing living from non-living entities, we need to analyze the options provided in the question. Here’s a step-by-step breakdown of the reasoning process:

### Step 1: Understand the Characteristics of Living Organisms
Living organisms exhibit certain characteristics that differentiate them from non-living entities. Key characteristics include growth, reproduction, metabolism, irritability (response to stimuli), and homeostasis.

### Step 2: Analyze the Options
Now, let's look at the options provided:

1. **Growth and Locomotion**: While growth is a characteristic of living organisms, locomotion is not exclusive to living organisms (e.g., non-living things can move due to external forces).

2. **Irritability and Locomotion**: Irritability (response to stimuli) is a characteristic of living organisms, but locomotion, as mentioned, does not distinctly separate living from non-living.

3. **Respiration and Excretion**: Both respiration (the process of converting food into energy) and excretion (removal of waste) are metabolic processes that are essential for living organisms. These processes are defining features of life.

4. **Reproduction and Locomotion**: Reproduction is a characteristic of living organisms, but again, locomotion does not serve as a definitive characteristic.

### Step 3: Identify the Best Reasons
From the analysis, the best reasons for distinguishing living from non-living are found in option 3: **Respiration and Excretion**. These processes are essential for the survival and functioning of living organisms and are not found in non-living entities.

### Conclusion
The two best reasons for distinguishing living from non-living are **Respiration and Excretion**.

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