What is true about the isolated small tribal population.?

Options

A. There is a decline in population as boys marry girls only from their own tribe
B. Hereditary diseases like colour blindness do not spread in the isolated population
C. Wrestlers who develop slrong body muscle in their life time pass this character on to their progeny.
D. There is no change in population size as they have a large gene pool

Answer

To answer the question "What is true about the isolated small tribal population?", we will analyze the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Isolated Small Tribal Populations**:
- Isolated small tribal populations are characterized by limited gene flow, meaning that they do not frequently interbreed with outside populations. This isolation can lead to unique genetic traits and challenges.

2. **Analyzing the Options**:
- **Option A**: "There is a decline in population as boys marry girls only from their own tribe."
- This statement is true. In isolated populations, inbreeding occurs, where individuals marry within their tribe. This can lead to a decrease in genetic diversity and reproductive fitness, resulting in a decline in population size over time.

- **Option B**: "Hereditary diseases like color blindness do not spread in the isolated population."
- This statement is false. If a hereditary disease is present in the isolated population, it can spread among the members due to the lack of new genetic material from outside the population. Inbreeding can actually increase the prevalence of such diseases.

- **Option C**: "Wrestlers who develop strong body muscles in their lifetime pass this character on to their progeny."
- This statement is false. Acquired traits, such as muscle development from training, are not inherited genetically. Only genetic traits can be passed to offspring.

- **Option D**: "There is no change in population size as they have a large gene pool."
- This statement is false. Isolated small tribal populations typically have a small gene pool due to limited interbreeding, which can lead to changes in population size, often resulting in a decline.

3. **Conclusion**:
- The only accurate statement regarding isolated small tribal populations is **Option A**: "There is a decline in population as boys marry girls only from their own tribe."