Zoology Practical Experiment No 1

EXPERIMENT NO 1

TITLE-TO STUDY PERMANENT SLIDE OF PARAMECIUM

Comments on paramecium

Important character: Paramecium is a unicellular and microscopic organism.

Habit and Habitat: It is a freshwater organism found in ponds, ditches, rivers, rice fields etc. It is abundant in stagnant water, where organic matter is plenty.

1. Shape and size:-It’s interior end is blunt and semicircular while the posterior end is pointed. It’s shape is just like that of the slope of the shoe. So, it is named as “Slipper animalcule”. It’s  size is variable, ranging from 0.06 to 0.3 mm long.

2. Pellicle: It is a thin and elastic membrane which externally covers the body. Function:-It gives and maintains the fixed shape of the body.

3. Cilia: These are the small, numerous hair like covering the entire body surface. These are longer in the posterior end called caudal tuft. Function: Cilia help in locomotion and food collection.

4.Oral groove: It is a large depression situated ventrally near the anterior end. It finally terminates into a food vacuole through vestibule.  Function: The oral groove,  vestibule and cytopharynx  together form feeding apparatus.

5. Trichocysts: These are the rod shaped structure just below the pellicle. Function: The trichocysts help in defence as well as in offence. According to modern views it also helps in sticking.

6. Cytopyge: It is situated on the ventral surface of the oral groove. It is also called as permanent cell anal spot. Function: It is used to egest out undigested food. It also acts as excretory organ.

7. Nuclear apparatus: paramecium is a binucleate (two nuclei) with dimorphism.

*Mega-nucleus (macro-nucleus): It is longer kidney shaped nucleus. Function: It controls the metabolic activities of the body.

*Micro-nucleus: It is smaller rounded nucleus situated in the depression of mega-nucleus. Function: It controls the reproduction.

8. Contractile Vacuoles: There are two contractile vacuoles one on each side of the body. Each contractile vacuole is surrounded by 6 to 8 radial canals which collect water. Function: Contractile vacuoles function as osmoregulation.