General and Distinctive Features of the Kingdom Protoctista


This Kingdom comprises of unicellular and simple multicellular organisms whose cells have organized nucleus and membrane bound organelles. It includes the algae and protozoa.

Algae have chlorophyll hence make their own food through the process of photosynthesis. Protozoa are heterotrophic taking in ready-made food.

Other organisms, which are included in this Kingdom are red algae, Brown algae, Amoeba, Euglena, plasmodium, trypanosome and paramecium.


General features of Kingdom Protoctista

  • Some are autotrophs, for example Euglena while others are multicellular.
  • They are all eukaryotes with most of them having locomotory structure.
  • Most of them live in moist places or in water.

Distinctive features

  • Most are unicellular eukaryotes
  • They reproduce by binary fission

Phyla of the Kingdom Protoctista

The phyla of kingdom protoctista include the following:

1.Euglenophyta e.g. Euglena

2.Rhizopoda e.g. Amoeba

3.Zoomastigma e.g. Trypanosoma

4.Apicomplexa e.g. Plasmodium

5.Oomycota e.g. White root

6.Chlorophyta e.g. Spirogyra

7.Ciliophora e.g. Paramecium

8.Rhodophyta e.g. Red algae
  

Structure of Amoeba and Paramecium

  • Amoeba belong to phylum Rhizopoda, organisms with the following extra features:
  • They are eukaryotes
  • Unicellular
  • Parasitic
  • They move using pseudopodia; Pseudopodia are projection of the cytoplasm that extend and pull the amoeba forward or engulf food particles.




  • Advantages of Paramecium:
Are eaten by small water animals

  • Disadvantages of Paramecium:
Causes diseases of balantidium coli destroying the lining of intestines


Osmoregulation:
Paramecium has two contractile vacuoles and each is associated with permanent system of collecting channels, which empty, into the main vacuole.


Feeding:
Paramecium feed on bacteria. These are obtained from the surrounding water by the beating of the cilia-lining o the oral groove.


Reproduction:
Paramecium reproduces both asexually and sexually. The asexual method is more common and it is binary fission. Sexual method is called conjugation.


Movement:
In paramecium is caused by cilia beating. This movement is called ciliary movement.