Read the following statements and select the correct option w.r.t. population attributes
(a) Population density is necessarily measured in numbers
(b) Tiger census is often based on pug marks and fecal pellets
(c) Biomass is not a meaningful measure to know population size.
(d) Size of a population for any species is not a static parameter

Options

A. a & b
B. a & d
C. c & d
D. a,b & d

Answer

To solve the question regarding the population attributes, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Evaluate Statement (a)**:
- **Statement**: "Population density is necessarily measured in numbers."
- **Analysis**: Population density refers to the number of individuals of a species per unit area or volume. Therefore, it is indeed measured in numerical terms (e.g., individuals per square kilometer).
- **Conclusion**: This statement is **True**.

2. **Evaluate Statement (b)**:
- **Statement**: "Tiger census is often based on pug marks and fecal pellets."
- **Analysis**: In wildlife studies, particularly for tigers, census methods often include tracking pug marks (footprints) and fecal pellets (animal waste) to estimate the population and presence of tigers in an area. This method is widely accepted in wildlife management.
- **Conclusion**: This statement is **True**.

3. **Evaluate Statement (c)**:
- **Statement**: "Biomass is not a meaningful measure to know population size."
- **Analysis**: Biomass, which refers to the total mass of organisms in a given area, is a significant indicator of population size and health. It provides insights into the productivity and ecological status of a population. Therefore, this statement is misleading.
- **Conclusion**: This statement is **False**.

4. **Evaluate Statement (d)**:
- **Statement**: "Size of a population for any species is not a static parameter."
- **Analysis**: Population sizes are dynamic and can change over time due to various factors such as birth rates, death rates, immigration, and emigration. This variability is a fundamental characteristic of populations.
- **Conclusion**: This statement is **True**.

### Final Evaluation:
- From the analysis, we find that statements (a), (b), and (d) are true, while statement (c) is false. Therefore, the correct option that includes the true statements is:
**Option 4: A, B, D.**

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