The changes developed in an organism during its own life span due to environmental factors or use and disuse of organs are called …..................

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term that describes changes in an organism during its lifespan due to environmental factors or the use and disuse of organs.

2. **Identifying Key Concepts**: The key concepts to focus on are "changes during lifespan," "environmental factors," and "use and disuse of organs."

3. **Defining the Term**: The changes that occur in an organism during its lifetime as a result of its experiences or environmental influences are known as "acquired characters."

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