ARRANGED BY :FAJAR BAGAS SAPUTRA KELAS : XJ NO : 15
A. INTRODUCTION In five kingdom classification system designed by Whittaker. Protist are put in a sepparate kingdom. Protozoa, the animal like protist, are also put in this kingdom and separated from its usual place in the animal kingdom. The same goes for plant like protist. The term Protist was first used by Ernest Haeckel.
B. PROTIST CHARACTERISTIC Protist are a group of eukaryotic organism, either unicelluler or multicellular and have not yet shown real tissue differentiation. The characteristics of protists are : 1. Most are one-celled, but some have many cells. 2. Cells have a membrane arround the nucleus (eukaryotic). 3. Some get nutrients and energy by eating other organisms. 4. Some get energy from the sun, and nutrients from the water. 5. Most reproduce by splitting in two 6. Examples are paramecium, amoeba, and kelp
C. THE MEMBER OF PROTIST The members differ from one another in morphology and how they live. There are those with fungi , animal, or plant characteristic.1. Fungus-like Protists Fungus like protist consist of water molds and slime molds. Fungus-like protist characteristics have structure to produce spore, heterotrophic. Characteristic Fungus-like Protist : Live in water or moist environments Look like tini threads with a fuzzy covering Attack food such as potatoes, cabbage, and corn and can destroy whole crops Live in moist soil and on decaying plants and trees Very colorful Move by forming pseudopods
Fungus-like protists are heterotrophic, they cannot make their own food, andthus they must be able to move at some point in their lives. These protists containlong hyphae-like strands thus they contain the physical appearance of fungi. Thedifference lies in that the hyphae of fungi are white while the hyphae of protists areusually bright in color. The fungus-like protists can act as decomposers. They break down deadorganisms by releasing digestive enzymes into the dead organism. In the endmaterials useful to other living organisms are released into the surroundingenvironment. Water Molds (oomycota)Water molds are fungus-like protists that live in moist environments. They looklike tiny threads with a hazy covering (when in a damp environment). Most watermolds are decomposers, breaking down dead organisms; few water molds areparasites, living in or on other organisms.
Water molds attack foods such as potatoes, cabbage, and corn. They are capable ofcompletely destroying crops. An example of the devastation a water mold is capable ofdoing happened between the years of 1845 and 1860. The growing seasons at this timewas a cold and damp one; these are conditions that encourage the spread of the watermold Phytophthora infestans. This water mold is the cause of rotting potato plants (lateblight). It infested all of the potato crops in Ireland. During this period one third ofIrelands population died; they either starved to death or were killed by the infestedpotatoes.
Slime molds (Myxomycota)Gb. Dictyostellium discoideumSlime molds are a fungus-like protist that lives in moist soil, decaying plants, andtrees. They have a very bright appearance. Slime molds are single celled organisms. When conditions become unfavorablethe single celled organisms join together and act like a "multi-cellular"organism. The protists will then form a sporangia-a cluster of cells on top of astalk. The sporangia consist of living cells in a dormant stage, while the stalkconsists of dead cells that act as a foot and push the cells to favorable conditions.When conditions become favorable the "multi-cellular" organism separates itselfback into the single celled organisms.
The new communal structure produces a slimy covering and is called a slug becauseit so closely resembles the animal you sometimes see gliding across sidewalks. Theslug oozes toward light. When the communal cells sense that theyve come acrossmore food or better conditions, the slug stops. An example : Dictyostelliumdiscoideum3. Animal-like protistAnimal-like protists are called protozoans ("first animals") because it is thoughtthat they are the evolutionary history of animals. They share many common traitswith animals. All of the animal-like protists are heterotrophs; they are unable tomake their own food. But unlike animals, they are unicellular. Since they can’t maketheir own food they must be able to move through their environment and catchtheir food. The animal-like protists are divided into four groups based upon their means ofmobility and manners for catching their food. They are divided into: protists withpseudopods, protists with cilia, protists with flagella, and parasitic protists.
1. Protists with Pseudopods : A pseudopod is a "false foot" that slowly moves the protist. These protistsmove towards their food or prey by extending their cytoplasm into a "false foot". The"false foot" extends from the cytoplasm, attaches to the ground, and pulls the rest of thebody toward the food. The pseudopods are not only for the means of locomotion; theyalso capture the food. They capture the food by wrapping the "false foot" around theprey and bringing it into their bodies. One example of an animal-like protist withpseudopods is the Amoeba (see picture above).Gb. Amoeba Proteusamoebas are single celled animal-like protists that live in moist soil, freshwater, and saltwater. There are different types of Amoeba but they all use pseudopods as means oflocomotion and capturing food. Most of the Amoebas are free-living and eat things likeother protozoans and bacteria; few Amoebas are parasitic and live on or in otherorganisms, where they obtain nutrients.
An example of an Amoeba is Entamueba histolytica. This Amoeba is the cause ofamoebic dysentery, which is a deadly infectious disease found mostly in tropicalareas and usually in areas where sanitation is poor. This disease is the leading causeof death for infants and toddlers; their immune systems are not yet developed,therefore they cannot destroy the disease.
2. Protists with CiliaCilia are tiny hair-like structures that surround some protists. The cilia beat back andforth. This movement enables the animal-like protist to move through its aquaticenvironment. The cilia also help the organism capture food. When the cilia beat, theprey (food) is moved into its body. Cilia are composed of ten pairs of microtubules. The microtubules are arranged inwhat is known as the 9+2 configuration. Of the ten pairs of microtubules nine pairsform a circle. Inside the circle lies the tenth pair; this is how it got the name 9+2configuration.
One example of an animal-like protist with cilia is the Paramecium.Paramecium is one known ciliated protist. The cilia help the Paramecium push thefood and water into the cell body. The food then becomes enclosed in a vesicle filledwith enzymes. In this vesicle the enzymes help the organism to digest the food. The cilia can also helps the protist move towards the food/prey by beating theorganism through the aquatic environment. The cilia can become leg-like structuresunder the Paramecium allowing it to "run.“
3. Protists with Flagella :Flagella are long whip-like structures that move back and forth allowing the animal-likeprotist to move. Protists with flagella beat the long whip-like structure to move throughtheir aquatic environments. These organisms can be free-living; some are parasitic,living in moist tissues of plants and animals. Sometimes the parasitic protists help theirhost, but others are harmful. Flagella, like cilia, are composed of microtubules. They are arranged in a 9+2configuration. Nine of the pairs of microtubules form a circle around the tenth pair. One example of an animal-like protist with flagella is Giardia lamblia.
Parasitic Protists The parasitic protists are animal-like protists that live in or on another organism,obtaining all its nutrients from that host organism. Many of these protists are diseasecausing. These protists go in and out of the active stage and the dormant stage. Whenconditions are good for them they are active; when conditions are bad they becomedormant. One example of this parasitic animal-like protist is Plasmodium, which causesmalaria.Plasmodium Plasmodium is a parasitic animal-like protist. It is the cause of malaria. Plasmodium istransported through mosquitoes. While in the mosquito the Plasmodium is in a dormantstage. When it is transported into the human it becomes active. It is mostly found in thered blood cells of humans. The Plasmodium asexually reproduces inside the liver andthen enters the red blood cells. The red blood cells are destroyed in massive amounts.Merozoites are produced in some of the red blood cells. These merozoites develop intothe male and female gametophytes. The infected gametophytes are taken in through amosquito and the process begins all over again.
3. Plants-like Protistplant-like protists are autotrophic; they can make their own foods. They live in soil, onthe barks of trees, in fresh water, and in salt water. Plant-like protists are very importantto the earth because they produce an abundant amount of oxygen. They are the basisfor the aquatic food chain. These protists are similar to plants. Most are photosynthetic. Some have stem-likestructures called stipes and anchoring structures called holdfasts, while plants haveactual stems and roots. Many of these protists release their eggs into the environmentwhere the sperm will fertilize the egg. Plants on the other hand will retain the egg inthe "parent" plant where it will fertilize. Some examples of plant-like protists are: Euglenoids, Dinoflagellates, Chrysophytes,Green Algae, Red Algae, and Brown Algae.
1. EuglenoidsEuglenoids are plant-like protists that are usually found in fresh water. During theday these protists are autotrophic; they can make their own foods. When night fallsthey become heterotrophic; they are unable to make their own foods, and thus theymust be able to find it. Some Euglenoids have flagella to help them move during theheterotrophic stage. The Eugleoid is a single celled organism with an abundance of organelles. Theyhave an "eye spot" which covers a light-sensitive receptor. The cell will move toplaces where the light suits it best.
2. DinoflagellatesDinoflagellates are plant-like protists found in salt water. They are unicellular andhave flagella to help them move through the water. The Dinoflagellates are capableof glowing in the dark. They are the cause of Red Tide, when there is an outburst inpopulation and in turn water becomes red/brown in color. The Dinoflagellates can produce toxins. If a human eats seafood contaminatedwith the toxins he/she will have memory loss and other impaired brain functions.One dinoflagellate that has gotten out of control is Pfiesteria. Pfiesteria grows infertilizer and raw sewage. It has killed a billion fish along the costs of NorthCarolina, Maryland, and Virginia since 1991. gb. Pfiesteria piscicida.
3. ChrysophytesChrysophytes are plant-like protists found in toothpaste, scouring products, andfilters. Chrysophytes have a glasslike cell wall. The Chrysophytes are free-living,photosynthetic, unicellular protists. They consist of diatoms, golden algae, andyellow-green algae. Many Chrysophytes form colonies. The diatoms are photosynthetic. They contain a shell that is made of silica. The cellhas two parts that overlap. Over millions of years the shells become crushed and formthe sand found on the bottom of oceans and lakes. Golden algae have no cell wall. They do have scales made of silica. They also containchloroplast and they do photosynthesize. Yellow-green algae also have no cell wall. They are unable to move, but some dohave flagella to help assist movement when conditions become harsh. This algae iscommon in nearly all aquatic environments.
4. Green AlgaeGreen algae are plant-like protists that are structurally closest to plants. The green algaecan be seen in many forms. Most are unicellular, some live in colonies, and few aremilticellular. Green algae grows at the surface of the ocean, in marine waters, below thesurface of the soil, and in rocks, tree bark, in other organisms, and in snow.
5. Red AlgaeRed algae is a plant-like protist that can be found in aquatic areas; most live in marinewaters, but some are found in fresh waters as well. Not all red algae appear red. Thecolor depends on the pigmentation and chlorophyll abundance in the protist. They canappear green, purple, and black. The cell walls of red algae are composed of agar, whichgives it a slimy/slippery feeling. Humans use red algae every day. The red algae Eucheuma is used as thickeningagents in such things as paints, dairy products, and hair conditioners.
6. Brown AlgaeBrown algae is a plant-like protist found in cool temperature marine waters. Theyrange in colors from dark brown to golden, depending on the amount andarrangement of certain pigments. They range in size from thirty meters, such as giantkelp, to microscopic organisms. Macrocyctis is giant kelp. It is one of the most complex of all protistans. They aremulticellualr and contain stipes (stem-like structures), blades (leaf-like structures),and holdfasts (anchoring structures). Kelp often live in giant colonies, creating a kelpbed. These giant kelp beds act like underwater "forests". Many fish, bacteria, andother protistans live their lives with in the giant kelp "forests." Brown algae are found in many products such as: ice cream, pudding, jelly beans,salad dressing, canned foods, frozen foods, beer, cough syrup, toothpaste, floorpolish, cosmetics, and paper. Many people harvest kelp for food, mineral salt, andfertilizer for crops.