In which of the following animals dimorphic nucleus is found? (a) Amoeba proteus (b) Trypanosoma gambiense (c) Plasmodium vivax (d) Paramecium caudatum
Option D Dimorphic nucleus means two types of nuclei are present in P. caudatum – large macronucleus and small micronucleus. The macronucleus is roughly kidneyshaped and with inconspicuous nuclear membrane. Macronucleus is the somatic or vegetative nucleus and controls the daytoday metabolic activities of the cell. The micronucleus is lodged in a depression on the surface of the macronucleus. It is usually spherical, with a nuclear membrane and with diploid number of chromosomes. It controls the reproductive activities of the organism. Amoeba, Trypanosoma and Plasmodium have only one nucleus.
