Question

Kappa particles indicate:
A. Nuclear inheritance
B. Cytoplasmic inheritance
C. Mutation
D. Nucleocytoplasmic inheritance

Answer 1

Kappa particles were discovered by Sonneborn. They are the one that contain DNA and protein and they are about 2µ × in diameter. It is a kind of self-replicating unit. Some species of Paramecium contain kappa particles. These kappa particles produce a poisonous toxin that kills many animals.

Complete answer:
Kappa organisms are those organisms that contain the K gene in them. These Kappa particles are seen in some of the species of Paramecium like Paramecium aurelia. The animals which have these kappa particles produce a toxin called Paramecium. These particular strains are called killer strains. And this toxin kills the Paramecium sensitive animals (that means those animals which do not have kappa particles).
The number of kappa particles in an animal is very much important to make it a killer animal. At Least there should be 400 kappa particles to produce Paramecium toxins to make an animal killer.
These particles indicate cytoplasmic inheritance. Kappa particles are an inheritable cytoplasmic symbiont which is present in some strains of the Paramecium. This cytoplasmic inheritance is particularly caused by the expression of genes present in the extra-chromosomal segments.

Therefore, the correct answer is “option (b)”.

Note:
All the paramecium aurelia are not killer animals. The Kappa gene is the dominant gene and it is denoted by the symbol “K”. So, the homozygous dominant will be KK and the heterozygous condition will be Kk will have kappa particles. But the condition which is homozygous recessive kk will not have kappa particles. Then these animals will not be killer animals.