Extranuclear inhertance is due to the presence of genes in

Options

A. mitochondria and chloroplasts
B. nucleus and mitochondria
C. nucleus and chloroplasts
D. enndoplasmic reticulum and mitochondria.

Explanation

**Step-by-Step Solution:**

1. **Understanding Extranuclear Inheritance**: Extranuclear inheritance refers to the transmission of genetic material that occurs outside of the nucleus. This is distinct from the typical inheritance of genes that occurs through the nuclear DNA.

2. **Identifying the Source of Extranuclear Inheritance**: The genes responsible for extranuclear inheritance are found in certain organelles, specifically mitochondria and chloroplasts. These organelles contain their own DNA, which is separate from the nuclear DNA.

3. **Characteristics of Mitochondrial and Chloroplast DNA**: Mitochondria and chloroplasts are considered semi-autonomous organelles because they possess their own double-stranded circular DNA, as well as their own ribosomes and machinery for protein synthesis. This allows them to replicate independently of the nuclear DNA.

4. **Maternal Inheritance**: In the case of fertilization, the zygote inherits mitochondrial DNA exclusively from the mother, as the sperm contributes nuclear DNA but does not typically contribute mitochondria. This is referred to as maternal inheritance.

5. **Conclusion**: Therefore, extranuclear inheritance is due to the presence of genes in organelles such as mitochondria and chloroplasts, making the correct answer to the question the genes present in these organelles.

**Final Answer**: Extranuclear inheritance is due to the presence of genes in mitochondria and chloroplasts.

---