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.