Hereditary characters are due to :-

Options

A. Chromosomes
B. Gene
C. Blood
D. Placenta

Answer

To answer the question "Hereditary characters are due to:", we will analyze the given options step by step.

### Step-by-Step Solution:

1. **Understanding the Question**:
The question asks about the origin of hereditary characters, which are traits or characteristics that are passed from parents to offspring.

2. **Evaluating Option 1: Chromosome**:
- Chromosomes are structures found in the nucleus of cells that contain DNA and proteins.
- They serve as packages for DNA and play a role in the organization and regulation of genes.
- However, chromosomes themselves do not directly carry hereditary traits; they are more of a structural component.
- **Conclusion**: This option is incorrect.

3. **Evaluating Option 2: Gene**:
- Genes are segments of DNA located on chromosomes.
- They are the basic units of heredity and are responsible for carrying the information that determines traits.
- Genes dictate various hereditary characteristics, such as eye color, hair type, and many other traits.
- **Conclusion**: This option is correct.

4. **Evaluating Option 3: Blood**:
- Blood is a bodily fluid that performs various functions, including transporting oxygen and nutrients throughout the body.
- While blood can carry genetic information (like blood type), it is not the source of hereditary traits.
- **Conclusion**: This option is incorrect.

5. **Evaluating Option 4: Placenta**:
- The placenta is an organ that develops during pregnancy and provides nutrients and oxygen to the developing embryo.
- It protects the embryo but does not carry hereditary information itself.
- **Conclusion**: This option is incorrect.

### Final Answer:
The correct answer is **Option 2: Gene**. Hereditary characters are due to genes, which are the units of heredity located on chromosomes.