Question

When Paramoecium was subjected to X-rays, its macronucleus and one of the following stopped?
A. Locomotion, digestion, osmoregulation
B. Reproduction, digestion, locomotion
C. Reproduction, locomotion, osmoregulation
D. Reproduction, osmoregulation

Answer 1

Hint: The phenomenon in which there are two types of the nucleus in the cell-like in Paramoecium is known as nuclear dimorphism. The smaller nucleus is called the micronucleus involved in the reproductive processes. The larger nucleus is called the macronucleus involved in the regulation and control of metabolism. When the macronucleus is subjected to X-ray, it gets injured and the functions of metabolism are stopped which show impacts on locomotion, digestion, osmoregulation, etc.

Complete answer:
Locomotion-
Paramecium locomotion mainly occurs by the movement of cilia. Cilia helps to move forward and backward. While moving forward, cilia forcefully moves from anterior to posterior. Similarly, for backward movement cilia forcefully move from posterior to anterior.

Digestion-
The paramecium uses its cilia to glide the food along with some water into the cell mouth after it falls into the oral groove. The food vacuole travels through the cell, and then the back end first. As it moves along enzymes, the cytoplasm enters the vacuole and digests it.

Osmoregulation
Osmoregulation in Paramecium is the main function of the contractile vacuoles which are present in the body of the Paramecium. The concentration of the cytoplasm is higher than that of the surrounding water which results in endosmosis. Water diffuses in through the semipermeable pellicle.

Reproduction
A single paramecium has three nuclei- a large, (macronucleus) essential for its survival, while one or two smaller (micronuclei), necessary for sexual reproduction. Reproduction is mostly asexual by binary fission and can occur many times a day.

Thus, the correct answer is option A- Locomotion, digestion, osmoregulation.

Note: Paramecia are single-celled protists, naturally found in aquatic habitats. They are commonly oblong or slipper-shaped and are coated with short hairy structures called cilia. Certain paramecia can easily be cultured in labs and serve as useful model organisms.