Monday, 10 June 2013

PROTOZOA

CULTIVATING PROTOZOA IN THE CLASS
 Cultivating protozoa has also been a class project. We collected dry leaves from the school grounds and placed them in a bowl with water. After a few days we added some rice. We left this preparation for aproximately 2 weeks. After this time we made microscopic preparations and were suprised to see a wide range of protozoa. The protozoa varied in shape and size and also in their motility. Some moved very quickly with their cilia, others used their flagellum, some moved in circles. The most suprising was a protozoa that curled their flagellum like a spring and then stretched it very quickly in a like jumping movement. We identified this protozoa as vorticela. We also saw paramecium, cosmarium, navicula, vorticela etc. We were also lucky to see microscopic nematodes in some of the samples.





Check out these videos! You can see many moving protozoa!! These are two of our samples!!


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video

Sunday, 9 June 2013

SCIENCE FAIR PROJECT - PROTOZOA - By Álvaro Méndez

Protozoa panel by Álvaro Méndez
Protozoa
Protozoa are a diverse group of unicellular eukaryotic organisms.



Characteristics
Protozoa commonly range from 10 to 52 micrometers, but can grow as large as 1 mm, and are seen easily by microscope. The largest protozoa known are the deep-sea dwelling xenophyophores, which can grow up to 20 cm in diameter.

Álvaro making a model of Vorticela


Motility and digestion
Tulodens are 2 of the slow-moving form of protozoa . They move around with whip-like tails called flagella, hair-like structures called cilia, or foot-like structures called pseudopodia. Others do not move at all. Protozoa may absorb food via their cell membranes, amoebas, surround food and engulf it, and yet others have openings or "mouth pores". All protozoa digest their food in compartments called vacuoles.
Ecological role
Protozoa are an important food source for microinvertebrates. As predators, they prey upon unicellular or filamentous algae, bacteria, and microfungi. Protozoa are consumers, both herbivoresand carnivores. They also control bacteria population.
Reproduction
Protozoa can reproduce by binary fission or multiple fission. Some protozoa reproduce sexually, some asexually. An individual protozoan is hermaphrodite.
Classification
They are classificated into ciliates, mastigophorans, and apicomplexans. Most protozoa can move about on their own.
Human diseases
Some protozoa are human parasites, causing diseases. Examples of human diseases caused by protozoa:
Malaria
Amoebiasis

Information source - Wikipedia


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Alvaro's model of Vorticela. This protozoa "jumps" by  curling and stretching its flagellum.




                           
                                      Protozoa stand ready for the Science Fair