Dimorphic nucleus in Paramecium caudatum

The correct answer to the question is option D - Paramecium caudatum. Paramecium caudatum is a unicellular organism belonging to the group of ciliates. It is commonly found in freshwater environments. One of the distinguishing features of Paramecium caudatum is its dimorphic nucleus.

Dimorphism in Paramecium caudatum

Dimorphism refers to the existence of two distinct forms or shapes within a single species. In Paramecium caudatum, dimorphism is observed in the nucleus. The organism possesses two types of nuclei - a large macronucleus and a smaller micronucleus.

1. Macronucleus: The macronucleus is the larger of the two nuclei and is responsible for the normal functioning and metabolism of the cell. It contains multiple copies of the genome, which are actively transcribed to produce RNA.

2. Micronucleus: The micronucleus is a smaller nucleus and is involved in the sexual reproduction and genetic exchange of Paramecium caudatum. It contains the genetic material in the form of diploid chromosomes.

Function of the dimorphic nucleus

The dimorphic nucleus in Paramecium caudatum serves different functions:

1. Macronucleus: The macronucleus plays a crucial role in the day-to-day activities of the cell. It regulates the cellular processes such as metabolism, growth, and reproduction. The macronucleus undergoes regular fragmentation and reorganization during asexual reproduction.

2. Micronucleus: The micronucleus is involved in the sexual reproduction of Paramecium caudatum. During conjugation, two Paramecium individuals exchange genetic material by swapping micronuclei. This genetic exchange promotes genetic diversity and allows for the formation of new combinations of genes.

Conclusion

In conclusion, the dimorphic nucleus is found in Paramecium caudatum. This unicellular organism possesses a macronucleus, responsible for day-to-day cellular functions, and a micronucleus, involved in sexual reproduction and genetic exchange. Understanding the dimorphic nucleus in Paramecium caudatum provides insights into the complex biology and reproductive strategies of this fascinating organism.