What Are The Characteristics/features Of The Phylum Protozoa?

The characteristics of phylum protozoa are that they are single-celled (otherwise known as unicellular) organisms that are microscopic (three to a thousand microns). They can live alone or in colonies and are the most primitive and simple of all animals. They have no germ layers, tissues or organs but they have intracellular organelles. Their bodies have no symmetry and can be bilateral, spherical or radial.

The main diet for protozoa is bacteria, but they will also eat other protozoa and fungi. For some, feeding takes place by absorbing food through their cell tissues, while others surround and engulf their food. When they are digesting their food, they release nitrogen, which is a vital element for plants and other living creatures.

An example of phylum protozoa is amoeba, which almost every schoolchild learns about and which is famous for its ability to change its shape. If you have a microscope and want to examine amoeba for yourself, get a glass jar and hold it upside down under the water of a pond just above the bottom. Tilt it slowly so that all of the air escapes from the jar and so the top layer of the soil from the pond is sucked into it. It is this section of the pond that amoeba usually inhabit.

When you examine this under a microscope, it will initially look just like dirt, but if you examine it closely, there is a very good chance that you will notice some gelatinous spheres. Those are your amoeba.

There are many different species of amoeba, with the largest one being the pelomyxa palustris, which can sometimes be as big as 5mm and visible to the naked eye.

Respiration for phylum protozoa is achieved through the general outer surface of the body, as is excretion. Reproduction for these creatures is asexually by binary or multiple fissions.

Free living protozoa mostly aquatic, inhabiting fresh and marine waters and damp places. Parasitic and commensal Protozoa live over or inside the bodies of animals and plants.
The including animals are small size, usually microscopic animals, originally not visible without a microscope.

These are simplest and most primitive of all animals.Body unicellular, containing one or more nuclei and organelles, with little or no histological differentiation into tissues and organs.

Solitary or form loose colonies in which individuals remain alike and independent.
Body symmetry none, bilateral, radial or spherical.Body is naked or bounded by a pellicle and provided often with simple to elaborate shells or exoskeletons.Cell which forms usually constant varied in some, while changing with environment or age in many.Locomotory organs are finger –like Pseudopodia or whip like flagellated or hair like cilia or absent.

Nutrition may be holozoic holophytic, saprophytic or parasitic.
Respiration is through general outer surface of the body.
Excretion is through general surface or through contractile vacuoles which also serve for osmo-regulation.Reproduction is asexually by binary or multiple fission. Encystment is commonly occurs to help in dispersal as well as to resist unfavorable conditions of food and temperature.

1, they are mostly microscopic
2, there are no germ layer present.
3, there is no organ or tissue.
4, all symmetry are represented.

Habitat:- they are either fresh water or marine or found in moist places
organizations:-in most of the protozoans , the cytoplasm is differentiated into outer ectoplasm and inner ectoplasm.
Body covering :- the body of some protozoa like amoeba is covered by thin plasma membrane

Phylum protozoa is animal kingdom's one, is most primitive, the simple, the most
low status unicellular animal. The protozoon gate type approximately has 30000
kinds. The protozoon is the single cell, in the cell has specialized each kind
of butcher, has the maintain life and continues all functions which the
descendant must, like motion, nutrition, breath, excretion and reproduction and
so on. Each protozoon is a complete organism.

Protozoa is basically a microorganism which can be classified as a unicellular eukaryotes. Such as Amoeba, ciliate etc. Following are the characteristics of Protozoa:

- They are unicellular microorganisms.
- They grow up to 1 mm.
- They can be seen only under a microscope.
- They exist in aqueous environments and soil.
- They prey upon unicellular or filamentous algae, bacteria etc.
- They can be herbivores or consumers in the decomposition chain.
- They help in controlling bacteria population.
- They are a great food source for micro invertebrates.

Unicellular
Requires moisture
Reproduce asexually