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 statements about population attributes, we will analyze each statement one by one:

1. **Statement (a): Population density is necessarily measured in numbers.**
- Population density refers to the number of individuals of a species per unit area or volume. It is indeed measured in numbers (e.g., individuals per square kilometer). Therefore, this statement is **true**.

2. **Statement (b): Tiger census is often based on pug marks and fecal pellets.**
- In wildlife studies, particularly for tigers, researchers often use pug marks (footprints) and fecal pellets (droppings) to estimate the population size and presence of tigers in a given area. This method is indeed commonly used. Thus, this statement is **true**.

3. **Statement (c): Biomass is not a meaningful measure to know population size.**
- Biomass, which refers to the total mass of organisms in a given area, can be a meaningful measure of population size, especially in ecological studies. It helps in understanding the energy flow and the productivity of an ecosystem. Therefore, this statement is **false**.

4. **Statement (d): Size of a population for any species is not a static parameter.**
- The size of a population can fluctuate due to various factors such as birth rates, death rates, immigration, and emigration. Hence, it is not a static parameter and can change over time. This statement is **true**.

Now, summarizing the evaluations:
- Statement (a): True
- Statement (b): True
- Statement (c): False
- Statement (d): True

Based on this analysis, the correct options regarding population attributes are **(a), (b), and (d)**.

**Final Answer: The correct option is (a), (b), and (d) are true statements.**

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