What is true about the isolated small tribal populations ?

Options

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

Answer

To answer the question "What is true about the isolated small tribal populations?", we can analyze the statements provided in the context of genetics and population dynamics. Here is a step-by-step breakdown:

### Step-by-Step Solution:

1. **Understanding Gene Pool**:
- Isolated small tribal populations typically have a limited number of individuals. This results in a smaller gene pool compared to larger populations. A gene pool is the total set of genes, including all the alleles for each gene, present in a population.

**Hint**: Remember that a smaller population size usually leads to a smaller gene pool.

2. **Acquired Characteristics**:
- The statement regarding wrestlers developing strong muscles and passing this trait to their offspring is incorrect. Acquired characteristics (traits developed during an individual's lifetime) cannot be inherited. Genetic traits are passed down through genes, not through acquired characteristics.

**Hint**: Distinguish between inherited traits (genetic) and acquired traits (environmental).

3. **Inbreeding and Genetic Disorders**:
- In isolated populations, inbreeding can occur due to limited mating options. This can lead to an increased prevalence of hereditary diseases, such as colorblindness, because the gene pool is not diverse enough to prevent the expression of recessive traits.

**Hint**: Inbreeding increases the chances of recessive genetic disorders appearing in a population.

4. **Population Decline**:
- The statement about boys marrying girls only from their own tribe is significant. This practice limits gene flow and can lead to a decline in population size over time, as there is less genetic diversity and fewer new individuals entering the population.

**Hint**: Consider how limited mating options can affect population dynamics over generations.

5. **Conclusion**:
- The correct understanding of isolated small tribal populations is that they have a small gene pool, are prone to inbreeding, and may experience population decline due to limited mating options and lack of gene flow.

### Final Answer:
The true statement about isolated small tribal populations is that there is a decline in population as boys marry girls only from their own tribe, leading to limited genetic diversity and potential inbreeding.