For which of the following cases, population density can be easily determined by utilising non-biological parameter ?

Options

A. Fish density
B. Density of bacteria in culture plate
C. siberian of cranes at Bharatpur wetlands
D. Tiger census

Answer

To determine which case allows for the population density to be easily assessed using non-biological parameters, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Population Density**: Population density refers to the number of individuals of a species per unit area or volume. It can be influenced by various factors, including both biological (living organisms) and non-biological (abiotic) parameters.

2. **Identify Non-Biological Parameters**: Non-biological parameters are typically abiotic factors such as temperature, water availability, pH, light, and dissolved oxygen levels. These factors can affect the habitat and the organisms living within it but are not directly related to the organisms themselves.

3. **Evaluate Each Option**:
- **Fish Density**: Fish density can be assessed using non-biological parameters such as water presence, temperature, and dissolved oxygen levels. These abiotic factors are crucial for fish survival and can indicate the density of fish populations in a given aquatic environment.
- **Number of Bacteria in a Culture Plate**: This is a biological measure, as it directly counts living organisms (bacteria) and does not rely on non-biological parameters.
- **Siberian Cranes in Bharatpur**: Counting Siberian cranes involves biological tracking methods, such as GPS, which are based on the organisms themselves, not on abiotic factors.
- **Tiger Sensors**: Similar to the cranes, tiger sensors rely on biological tracking and do not utilize non-biological parameters for counting the population.

4. **Conclusion**: Among the options provided, fish density is the only case where population density can be easily determined using non-biological parameters. Therefore, the correct answer is the first option (fish density).

### Final Answer:
Population density can be easily determined by utilizing non-biological parameters in the case of **fish density**.

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