Protists

The amoebae extends two pseudopodia by microtubule extension and surrounds the bacterial prey, then, instead of reeling in the prey, the amoebae drags itself up to the trapped bacteria and then engulfs it by a form of phagocytosis. There the bacteria is digested by many different enzymes designed for the job.

An amoeba and a Volvox are two examples of protists. The amoeba is heterotrophic (does not make its own food), and the Volvox is autotrophic (makes its own food through photosynthesis).

Protozoa and Algae

Idk... but i need to kow for a project.

So i guess im asking the same question. lol

Paramecium belongs to the phylum Ciliophora, which is characterized by the presence of cilia used for movement and feeding.

Some dinoflagellates produce toxins that can accumulate in shellfish, leading to illnesses like paralytic shellfish poisoning when consumed by humans. Other dinoflagellates can cause harmful algal blooms, leading to fish kills, contaminated water, and respiratory issues when aerosolized.

Protists are tiny organisms in the Domain of Eukarya. Historically they were part of the Kingdom of Protista, but this is no longer the case. Protists are incredibly diverse, and there is little to bind them together as a grouping, except for the simplicity of their structure. Protists have either one cell, or else have multiple cells without any specialized tissues. This is what distinguishes protists from other eukaryotes like animals, plants, and fungi. Historically, protists were divided into three groups, based on which of the major Kingdoms they were most similar to. Although this particular classification is no longer formally used, many people still use them to describe protists. The protozoa are the protists which have the most in common with animals. The protophyta have more in common with plants and slime molds are most similar to fungi. Some protists are motile, able to move by using flagella, pseudopodia, or cilia, while others are unable to move. They may live on their own by absorbing energy from sunlight, or they may live symbiotically with a host organism. In some cases, protists may engage in a mutual symbiotic relationship, where the protists gain energy from the host, but perform some beneficial service in return, but often they are parasitic, simply leeching energy off of the host. Protists play fundamental roles in the ecosystems of the world. As such, many protists are quite beneficial to humans. Others, however, are harmful to humans. Protists such as apicomplexa and kinetoplastids cause any number of diseases that afflict human beings, such as malaria, and some protists, such as the amoeba, can cause serious illness when their population gets out of control in the body. The protophyta, or algae, are the protists which play the most beneficial role for humans. Many of the protophyta form the basis of the food chain which drives the engine of life on the planet. The algae create food for other organisms, growing and expanding by absorbing the light of the sun through photosynthesis and serving as food for the lowest-level animal organisms, which in turn serve as food all the way up the food chain. The vast majority of the plankton in the ocean consists of various protists. These algae often look like plants, but they differ in a number of key ways: they have no leaves, no stems, no roots, and no distinct helper parts. In spite of this, they may reach large sizes not usually associated with simple oranisms. Protophyta not only create food, but they also respirate oxygen, making them crucial for sustaining animal life on the planet. In fact, algae generate about half of the oxygen generated by photosynthesis on the planet. It is beyond doubt that the protists play one of the most important roles in sustaining human health on the planet. Without the protists, the ocean’s food chain would collapse, and in turn the food chain as a whole would crumble, and at the same time oxygen would be reduced drastically.

Euglenas are single celled protists, not plants. However, they can perform photosynthesis (the process of making their own food from air, light, and water). Oddly enough, euglenas can also eat food, like single-celled animals.

Protista is one of the four generally accepted kingdoms in the superkingdom Eukaryota. Biologists generally accept the following kingdoms:-

Superkingdom Prokaryota - single celled organisms with no distinct cell nucleus

kingdom Monera - bacteria (is an argument for 2 Eubacteria % archebacteria

Superkingdom Eukaryota

kingdom Animalia - multicelled organisms with no organelles other than nucleus

kingdom Plantae - nutrition derived from photosynthesis via chloroplasts

kingdom Fungi - don't photosynthesize - nutrition from rotting organic matter

kingdom Protista - see distinction below

Many biologists do not include viruses because 1) there are no free living forms 2) they are totally dependant on there host for reproduction. On the other hand 1) they do have an existence of their own separate to the host and 2)are subject to natural selection.

Prions are also arguably alive for the same raasons.

These divisions have been built up and generally agreed upon over centuries. No one scientist can be sttributed with the discovery of a "protist". They have been continually discovered since the invention of the microscope. Before the divisions above, life on Earth was once divied into only plants and animals.

Protists are difficult to define. Many share characteristics with fungi, some with animals and some with plants. They are generally single celled but when they join together and form structures such as filaments, the cells are all still identical.

Ameba's use pseudopods

It can also be called a penis

Plasmodium is a genus of parasitic protozoa. Infection with these parasites is known as malaria. The genus Plasmodium was created in 1885 by Marchiafava and Celli. Currently over 200 species in this genus are recognized and new species continue to be described.[1] [2] Of the 200+ known species of Plasmodium, at least 10 species infect humans. Other species infect animals, including birds, reptiles and rodents. The parasite always has two hosts in its life cycle: a mosquito vector and a vertebrate host. The genus is currently (2006) in need of reorganization as it has been shown that parasites belonging to the genera Haemocystis and Hepatocystis appear to be closely related to Plasmodium. It is likely that other species such as Haemoproteus meleagridis will be included in this genus once it is revised. Life Cycle Mosquitoes of the genera Culex, Anopheles, Culiceta, Mansonia and Aedes may act as vectors. The currently known vectors for human malaria (> 100 species) all belong to the genus Anopheles. Bird malaria is commonly carried by species belonging to the genus Culex. Only female mosquitoes bite. Aside from blood both sexes live on nectar, but one or more blood meals are needed by the female for egg laying as the protein content of nectar is very low. The life cycle of Plasmodium was discovered by Ross who worked with species from the genus Culex. The life cycle of Plasmodium is complex. Sporozoites from the saliva of a biting female mosquito are transmitted to either the blood or the lymphatic system [3] of the recipient. The sporozoites then migrate to the liver and invade hepatocytes. This latent or dormant stage of the Plasmodium sporozoite in the liver is called the hypnozoite. The development from the hepatic stages to the erythrocytic stages has until very recently been obscure. In 2006[4] it was shown that the parasite buds off the hepatocytes in merosomes containing hundreds or thousands of merozoites. These merosomes have been subsequently shown[5] to lodge in the pulmonary capilaries and to slowly disintegrate there over 48-72 hours releasing merozoites. Erythrocyte invasion is enhanced when blood flow is slow and the cells are tightly packed: both of these conditions are found in the alveolar capilaries. Within the erythrocytes the merozoite grow first to a ring-shaped form and then to a larger trophozoite form. In the schizont stage, the parasite divides several times to produce new merozoites, which leave the red blood cells and travel within the bloodstream to invade new red blood cells. The parasite feeds by ingesting haemoglobin and other materials from red blood cells and serum. The feeding process damages the erythrocytes. Details of this process have not been studied in species other than Plasmodium falciparum so generalisations may be premature at this time. At the molecular level a set of enzymes known as plasmepsins which are aspartic acid proteases are used to degrade hemoglobin. The parasite digests 70-80% of the erythrocyte's haemoglobin [6] but utilises only ~15% in de novo protein synthesis [7] The excess amino acids are exported from the infected erythorocyte by new transport pathways created by the parasite. [8] The reason proposed for this apparently excessive digestion of haemoglobin is the colloid-osmotic hypothesis [9] which suggests that the digestion of haemoglobin increases the osmotic pressure within the infected erythrocyte leading to its premature rupture and subsequent death of the parasite. To avoid this fate much of the haemoglobin is digested and exported from the erythrocyte. This hypothesis has been experimentally confirmed. [10] Most merozoites continue this replicative cycle, but some merozoites differentiate into male or female sexual forms (gametocytes) (also in the blood), which are taken up by the female mosquito. In the mosquito's midgut, the gametocytes develop into gametes and fertilize each other, forming motile zygotes called ookinetes. The ookinetes penetrate and escape the midgut, then embed themselves onto the exterior of the gut membrane. Here they divide many times to produce large numbers of tiny elongated sporozoites. These sporozoites migrate to the salivary glands of the mosquito where they are injected into the blood and subcutaneous tissue of the next host the mosquito bites. The majority appear to be injected into the subcutaneous tissue from which they migrate into the capillaries. A proportion are ingested by macrophages and still others are taken up by the lymphatic system where they are presumably destroyed. The sporozoites which successfully enter the blood stream move to the liver where they begin the cycle again. The pattern of alternation of sexual and asexual reproduction which may seem confusing at first is a very common pattern in parasitic species. The evolutionary advantages of this type of life cycle were recognised by Mendel. Under favourable conditions asexual reproduction is superior to sexual as the parent is well adapted to its environment and its descendents share these genes. Transferring to a new host or in times of stress, sexual reproduction is generally superior as this produces a shuffling of genes which on average at a population level will produce individuals better adapted to the new environment. Reactivation of the hypnozoites has been reported for up to 30 years after the initial infection in humans. The factors precipating this reactivation are not known. In the species Plasmodium malariae, Plasmodium ovale and Plasmodium vivax hypnozoites have been shown to occur. Reactivation was not thought to occur in infections with Plasmodium falciparum but there are been two reports to date suggesting that this may occur (see below) . It is not known if hypnozoite reactivaction may occur with any of the remaining species that infect humans but this is presumed to be the case. A report of recurrence of P. falciparum in a patient with sickle cell anaemia has been published [11] but this needs confirmation as hypnozoites are not known to occur in P. falciparum infections. A second report of P. falciparum malaria eight years after leaving an endemic area has also been published.[12] While this is consistent with the existence of a hypnozoite stage additional confirmation seems desirable.

I don't know where they are mainly found but most are found in moist and wet areas and they can also be found in tree trunks or other organisms.

An amoeba replicates by splitting in half asexually so that each daughter cell is the same as the parent. Running this process backward from the present, each existing amoeba is the same as its predecessor (fungible) back as far in time as the first amoeba existed. In this regard the amoeba is immortal.

Now it get a bit picky.

The above assumes that no genetic changes have occurred since amoeba #1. This cannot be proved. Replication errors, chromosome damage by radiation etc may have happened to create slightly better or worse (at least different) amoebas that are the ancestors of all amoebas today.

The term "immortal" needs some thought to. No individual amoeba is necessarily immortal. Each amoeba can be killed. Only the amoeba pattern is immortal so far.

Then there is the Star Trek transporter problem. When Kirk is transported he is destroyed at the sending end and reconstituted at the receiving end. Is he the same Kirk? Amoebas are the same. The "mother" amoeba is essentially destroyed as it divides to create the daughters. Do the daughters share all the learnings of the mother? or would they see themselves as unique?

They can be the primary producers in the ecosystem, particularly in the ocean as part of the plankton. Others such as Kinetoplastids, are responsible for a range of human diseases such as malaria and sleeping sickness. Some cause harmull potato blight

Diatoms are microscopic plants (phytoplankton) found in oceans and lakes. Their cell wall is made of Silica which remain after the diatom dies. Diatoms are single celled, photosynthetic algae this means that they are producers!!

Amoebas move by means of pseudopodia, or the sarcodine protozoa. This characteristic movement involves the extrusion of the cytoplasm for movement or for feeding by engulfing food.

It's unlikely for an amoeba to survive in a properly chlorinated swimming pool. However, if the pool isn't maintained properly and the water temperature is warm, amoebas like Naegleria fowleri can potentially thrive and pose health risks to humans.

Protists are the miscellaneous group out of the six kingdom, so as long as they are eukaryotic they are protist. They can be heterotrophs or autotrophs, they can be multicellular or single-celled

naturalists referred to Amoeba as the Proteus animalcule after the Greek godProteus who could change his shape. The name "amibe" was given to it by Bory de Saint-Vincent,[3] from the Greek amoibè (αμοιβή), meaning change.[4]

it is important to study protist beacuse: (sorry i only know feww)

beacuse they help in the process of producing oxygen.

They are main base of food webs and food chains.

xDee

no.

an amoeba cell is a unicellular organism, which means that it is only made up of one cell

Some important points that might help. I took them from one website as they were (didnt re-phrase) "Algae is currently used in many wastewater treatment facilities, reducing the need for more dangerous chemicals. Algae can be used to capture the runoff fertilizers that enter lakes and streams from nearby farms. Algae is used by some powerplants to reduce CO2 emissions. The CO2 is pumped into a pond, or some kind of tank, on which the algae feed."

Protists only have one cell.

Most protists move and generate their movement with cilia, flagella, or pseudopodia (false feet).
Protists that are classified as animal-like are called protozoans and share some common traits with animals.
All animal-like protists are heterotrophs. Likewise, all animal-like protists are able to move in their environment in order to find their food. Unlike, animals, however, animal-like protists are all unicellular.