protista characteristics
Protista Characteristics
Protista is one of the classifications of animal kingdom. It has different sub groups and divisions. Their characteristic vary accordingly. To know the details read this article protista characteristics.
What are protistas? Prostista is a kingdom to which the eukaryotic microorganisms, protists belong. Protista was first observed by John Hogg in 1860s as primitive unicellular forms of both plants and animal. At that time, this kingdom was known as 'Protoctista', which literally means first established beings. Later in the year 1866, the term protista was coined by Ernst Haeckel. This kingdom belongs to the domain Eykarya. Recent classifications are being made by scientists where listing of organisms is done on hierarchical basis. They have different characteristics that distinguish them from other kingdoms. The most common examples protista include, amoeba, plasmodium, pararamecium, slime mold, red, brown and golden algae, fungi, diatoms, etc.
General Characteristics of Protista
- They are mostly unicellular but some are multicellular and colonial organisms.
- They are either free-living or parasitic.
- They have aerobic mode of respiration and have mitochondria for cellular respiration.
- They are true eukaryotes and are nucleated.
- They have (9+2) arrangement of flagella and have membranous organelles.
- They reproduce both sexually (syngamy) and asexually.
- They are grouped into 3 categories: animal like (protozoa), fungus like, and plant-like.
- According to the categories, they have different modes of nutrition, like heterotrophy or autotropohy.
- Plant-like protists (algae) have chlorophyll and accessory pigments, named xanthophylls, phycobilins, and carotene.
- They are unicellular
- Animal like movement
- Flagellum present
- Presence of nucleus, chloroplasts, flagellum, and cell membrane
- Asexual reproduction
- Two part shell of silicon glass
- Golden brown in color
- Stores food in form of oil
- They are di-flagellated
- Phosphorescent algae
- Covered with plates
- Color renders 'red tides'
- Has toxins
- Presence of pseudopodia
- Shell composed of calcium
- They are heterotrophs
- Free living, saprophytic, mutualistic or parasitic
- Sarcodina: amoeba like movement (pseudopodia)
- Flagellates: moves with flagella
- Paramecium: moves with cilia
- Sporozoans: produce spores
- They are multicellular
- Change forms during life cycle
- Tend to live in damp climate
- Plasmodial (acellular), slime molds (Myxomycetes)
- Kingdoms: Chromista, Archaezoa, Protista/Protozoa
- Candidate Kingdoms: Archaezoa, Euglenozoa, Alveolata, Stramenopila, Rhodophyta