The Kingdom Protista

Kingdom Protista Domain Type of Cell Cell Structures Number of Cells Nutrition Examples Other Facts

If you look at a drop of pond water under a microscope, all the "little creatures" you see swimming around are protists. Kingdom Protista is considered the junk drawer kingdom because it is so diverse with many different kinds of organisms fitting into this kingdom.

Protists are any organisms that are not plants, animals, fungus, or prokaryotes. All protists have a nucleus and are therefore eukaryotic. Protists are either animal-like, plant-like or fungus-like.

Animal-like protists are heterotrophs. Plant-like protists are autotrophs – they contain chloroplasts and make their own food. Fungus-like protists are decomposers, they breakdown dead things and return the nutrients to the soil.

PROTOZOANS Animal-like protists are called protozoans. They are grouped according to how they move: 1) Zooflagellates 2) Sarcodines 3) Ciliates 4) Sporozoans

Zooflagellates Generally the smallest of the protozoa Have one or several long, whip-like projections called flagella. Flagellates use their flagella to move. They absorb food through their cell membranes. Live in lakes, streams, or within other organisms. Most reproduce asexually by mitosis and cytokinesis, some reproduce sexually by meiosis.

Giardia

Sarcodines Move and feed by use of pseudopods or cytoplasmic projections. Ameobas are the best known sarcodines. Other sarcodines are foraminiforans and heliozoans. Ameoboid movement is the type of locomotion in which the cytoplasm streams into the pseudopod and the rest of the cell follows. Phagocytosis is the method they use for eating in which they form a food vacuole. Reproduce by mitosis and cytokinesis.

Ciliates These are generally the largest protozoa. The most common example is a paramecium. They are covered with hair-like projections called cilia. Cilia act like tiny oars, moving the cell through the water in search of food. They eat the other two types of protozoa as well as bacteria. Ciliates are found in every aquatic habitat. Internal anatomy includes: trichocysts, macronucleus, micronucleus, gullet, anal pore, and contractile vacuole. Genetic variation occurs via conjugation in which they exchange a micronucleus.

Sporozoans They are parasitic. They do not move on their own. Often involve a complex life cycle that uses more than one host. The sporozoan Plasmodium causes the disease malaria. -The sexual phase of its life cycle takes place inside the mosquito. -The asexual phase of its life cycle takes place inside a host cell: liver cells and red blood cells.

ALGAES Plant-like protists are algae. Algae are eukaryotic autotrophs. Chlorophyll and Accessory Pigments allow algae to be photosynthetic. They, along with other eukaryotic autotrophs, form the foundation of Earth’s food chains. They produce much of Earth’s oxygen.

There are four unicellular phyla of algae: Euglenophyta Chrysophyta Bacillariophyta (Diatoms) Pyrrophyta (Dinoflagellates)

Euglenophytes They are both plant-like and animal-like. Euglena are autotrophs since they make food from sunlight Heterotrophs since they ingest food from surrounding water. They have two flagella, but no cell wall. Found in ponds and lakes throughout the world. Cell structures include: eyespot that helps find sunlight and a pellicle- intricate folded cell membrane Reproduce asexually by binary fission

Diverse group that have gold-colored chloroplasts Chrysophytes Diverse group that have gold-colored chloroplasts Cell walls contain pectin or a combination of pectin and cellulose. Store food in the form of oil. Reproduce sexually and asexually.

Bacillariophyta (Diatoms) They are photosynthetic autotrophs. They have thin cell walls made of silicon. The cell walls have fine lines and patterns that make them very unique. They make up a large portion of the world’s phytoplankton which are small photosynthetic organisms near the ocean’s surface. Provide us with ½ of the earth’s oxygen source.

DIATOMS

Pyrrophyta (Dinoflagellates) Half are photosynthetic and the other half live as heterotrophs. These algae have at least two flagella set at right angles to each other They have thick cell walls made of cellulose plates. Reproduce asexually by binary fission. Many are luminescent when agitated. Blooms of dinoflagellates cause “Red Tide.”

Algal Blooms Q: What is an algal bloom? A: an enormous mass of algae in salt or fresh water. In salt water it is sometimes called “red tide.” Q: What causes them? A: When there is an increase of nutrients in the water there is a rise in the algae that eat these nutrients. Q: Are they dangerous? A: Yes, because algae produces toxins and when there is an increase in algae, there is an increase in the toxins they produce and those toxins get concentrated in the bodies of the organisms that eat the algae and can kill them.

In feshwater, an algal bloom is called eutrophication. The rapid growth of algae in a pond or lake triggers a series of events with serious consequences: The layer of algae prevents sunlight getting through to other water plants. Those organisms die and sink to the bottom. Bacteria break them down and reproduce rapidly. Bacteria use up available oxygen and fish die. Only the algae survives .

Multicellular algae are classified by color: MULTICELLULAR ALGAES Multicellular algae are classified by color: 1) Red Algae 2) Brown Algae 3) Green Algae Example: Kelp

FUNGUS-LIKE PROTISTS Fungus-like protists are decomposers. They are heterotrophs that absorb nutrients from dead material. Unlike true fungi, they have centrioles and lack chitin in their cell walls. There are three types of fungus-like protists: 1) cellular slime molds 2) acellular slime molds 3) water molds

Cellular Slime Molds The individual cells remain distinct separated by cell membranes. Spend most of their life as free-living cells. When food is exhausted, they send out signals to reproduce and form large colonies that function as a single organism.

Acellular Slime Molds Go through a stage where cell membranes fuse forming large cells with many nuclei called plasmodia.

Water Molds Thrive on dead organic matter in water or some are plant parasites on land. Produce multinucleic filaments called hyphae. Display sexual and asexual reproduction within its life cycle. Example: the white “fuzz” growing on a dead fish. Caused the potato famine In the 1840’s in Ireland.

Kingdom Protista Concept Map