a) Explain "birth rate" in a population by taking a suitable example.
b) Write the other two characteristics which only a population shows but an individual cannot.

Explanation

### Step-by-Step Solution

#### a) Explanation of "Birth Rate" in a Population

1. **Definition of Birth Rate**: Birth rate, also known as natality, refers to the number of live births in a population over a specific period of time. It is typically expressed as the number of births per 1,000 individuals per year.

2. **Example**: Consider a pond with 20 aquatic plants. If we introduce 5 additional plants into the pond, the total population of plants becomes 25.

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