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Paramecium Movement

The way paramecia move is quite straightforward; usually, they will travel in a

straight line until they bump into something and navigate around it. They may,however, change course to reach food, and it is believed that the creatures

may have chemical sensors to alert them to potential sources of nutrition.

Watching one move around large obstacles can remind people of navigating

into small parking spaces, as it moves forward, backs up, turn, moves

forward, and so forth until it in the clear again.

Parameciapropel themselves by whiplash movements of their cilia, which are

arranged in tightly spaced rows around the outside of their body. The beat of

each cilium has two phases: a fast "effective stroke," during which the cilium is

relatively stiff, followed by a slow "recovery stroke," during which the cilium

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curls loosely to one side and sweeps forward in a counter-clockwise fashion.

The densely arrayed cilia move in a coordinated fashion, with waves of activity

moving across the "ciliary carpet," creating an effect sometimes likened to that

of the wind blowing across a field of grain.[10]

The Parameciumspirals through the water, as it progresses. When it happens

to encounter an obstacle, the "effective stroke" of its cilia is reversed and the

organism swims backward for a brief time, before resuming its forward

progress. If it runs into the solid object again, it will repeat this process, until it

can get past the object.[11]

It has been calculated that a Parameciumexpends more than half of its

energy in propelling itself through the water.[12]Its method of locomotion has

been found to be less than 1% efficient. This low percentage is, nevertheless,

close to the maximum theoretical efficiency that can be achieved by an

organism equipped with cilia as short as those ofParamecium.[13]

On the right is a diagram of a Euglena displaying its Organelles, which include:

Flagellum- A long, mobile filament that the Euglena uses to propel itself in its

environment

Reservoir- The part used for storage of nutrientsStigma- A light sensitive-spot that allows the Euglena to detect light, so that it may

move towards it in order to conduct photosynthesis

Chloroplast- Organelle that allows the organism to conduct photosynthesis

Contractile Vacuole- Expels excess water into the reservoir, or else the cell would

burst

Pellicle- Stiff membrane made of proteins and somewhat flexible, can also be used

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for locomotion when crunching up and down or wriggling

Nucleus- The central organelle which contains DNA and controls the cell's activity,

contained within the Nucleolus