23.4 Ecology of Protists

• Sleeping sickness.
• The tsetse fly and humans are part of the life cycle of Trypanosoma brucei.

• By the end of this section, you will be able to describe the function of protists in various ecological niches.
• Some protist species are essential components of the food chain, while others are not.
• Other protists are dangerous and cause devastating plant diseases.

• Protists provide nutrition to many other organisms.
• Protists are consumed directly in some cases.
• Protists serve as producers of nutrition for other organisms.

• Several species of ciliates are mixotrophic due to a symbiotic relationship with green algae.
• There is a temporary version of the secondarily endosymbiotic chloroplast found in Euglena.
• These associations are not limited to protists.
• The coral polyps that house zooxanthellae give corals a boost of energy to produce their calcium carbonate skeleton.
• The corals give the protist a protected environment and the compounds needed for photosynthesis.
• This type of relationship is important in poor environments.
• Without dinoflagellate symbionts corals die in a process called coral bleaching.
• Reef-building corals don't reside in waters deeper than 20 meters because insufficient light doesn't reach those depths for dinoflagellates.

• Coral polyps get their nutrition from dinoflagellates.

• The protists and their products are essential to the survival of many organisms.
• Protists feed a lot of the world's aquatic species.

• Approximately 25 percent of the world's photosynthesis is done by dinoflagellates, diatoms, and multicellular algae.

• Protists are part of the food chain.
• All aquatic organisms depend on protists for food.

• Protists don't just create food sources for sea-dwelling organisms.
• There are certain parabasalid species that help in the digestion of wood-eating insects.

• A pathogen is anything that causes disease.
• Parasitic organisms are harmful to the host organisms.
• A small number of protists are serious parasites that need to spread to other organisms to survive.
• Malaria, African sleeping sickness, amoebic encephalitis, and waterborne gastroenteritis are some of the parasites that are protist.
• Massive destruction of food crops is caused by protist pathogens.

• The World Health Organization reported over 200 million cases of Malaria in 2015.
• It is not well known that the North Central region of the United States, particularly Michigan, has thousands of lakes and numerous swamps, and that it has a disease called Malaria.
• The pale, sallow, bloated faces of people who came to Michigan before the civil war were the rule.
• Immigrants who had just arrived wore only healthy faces.
• Malaria killed more people in Michigan than it did in the Civil War.

• Malaria is caused by several species of the same family of parasites.
• Both a mosquito and a reptile are required to complete the life cycle of members of the Plasmodium species.
• The erythrocytic stage of the parasites is where they destroy the red blood cells and the exoerythrocytic stage is where they develop.
• Malaria is the leading cause of disease-related deaths in tropical regions of the world, accounting for 50 percent of all cases.
• In 2015, it was estimated that over 400,000 deaths were caused by Malaria.
• During the course of malaria, P. falciparum can destroy more than half of a human's circulating blood cells.
• The host immune system mounts a massive inflammatory response when the parasites burst from the red blood cells, releasing waste products into the bloodstream.
• The Anopheles gambiae is a mosquito that carries P. falciparum.
• Techniques to kill, sterilize, or avoid exposure to this mosquito species are crucial to malaria control.
• In parts of the world where Malaria is endemic, a type of genetic control has arisen.

• Unfortunately, this allele also has an unfortunate second effect, which is to cause sickle cell disease.

• Red blood cells are shown to be carriers of P. falciparum.
• The ring-shaped P. falciparum is staining purple in this light microscope image.

• The movie depicts the causes of Malaria.

• The disease Trypanosoma brucei is transmitted by tsetse flies in Africa and South America and is responsible for the deaths of cattle and horses.
• The human immune system is confused by this trypanosome because it changes its thick layer of surface glycoproteins with each infectious cycle.
• With each subsequent generation, the protist switches to a glycoprotein coating with a different molecule.
• Without the immune system clearing the parasites, T. brucei is capable of replicating continuously.
• Without treatment, T. brucei attacks red blood cells, causing the patient to lapse into a coma and eventually die.
• Mortality from the disease can be high during epidemic periods.
• Some of the lowest reported cases in 50 years have happened since 2009, when greater control measures led to a reduction in reported cases.

• The movie discusses the causes of African sleeping sickness.

• Chagas disease is caused by another species of trypanosome, T. cruzi.
• The "kissing bug" in the Triatoma family is the main cause of T. cruzi infections.
• The host is bitten during the night and then defecate on the wound to transmit the trypanosome to the victim.
• The victim scratches the wound, inoculating it with trypanosomes at the location of the bite.
• Most people never develop further symptoms after about 10 weeks in the chronic phase.
• In about 30 percent of cases, the trypanosome causes further damage to the heart and digestive system tissues in the chronic phase of infections, leading to malnutrition and heart failure due to abnormal heart rhythms.
• 10,000 deaths were caused by Chagas disease in 2008, and 10 million people are affected.

• There are trypanosomes in red blood cells.
• Food crops are destroyed by protist parasites of plants.
• Downy mildew is caused by the oomycete Plasmopara viticola.
• Plants with P. viticola have discolored leaves.
• In the 19th century, the French wine industry was nearly destroyed by the spread of downy mildew.

• The grape leaf has a disease called P. viticola on it.
• The Irish potato famine of the 19th century claimed the lives of 1 million people and led to the emigration of at least 1 million more from Ireland.
• As much as 70% of potato crops in parts of the United States and Russia can be wiped out when no pesticides are applied.

• The remnants were caused by an infection with P. infestans.
• The protist saprobes are specialized to absorb organic matter, such as dead organisms or their waste.
• Many types of oomycetes grow on dead animals.
• The function of saprobic protists is to return soil and water NPK.
• This process allows for new plant growth, which in turn feeds other organisms along the food chain.
• As organic carbon became "tied up" in dead organisms, life would cease to exist.

• Characteristics of Protists are older than 2 billion years old.
• Fossils older than this seem to be prokaryotes.

• Protists are very diverse in their biological characteristics and it is possible that they are descended from an ecological organization.
• The common ancestor of today's Eukarya had a variety of cell structures and characteristics, including cells with nuclei and reproductive strategies.
• The majority of single-celled protists are envelope.
• These organisms use different structures for histones and its chromosomes were linear and contained DNA motile.
• The nuclear genome seems to be related to transportation.

• The descendant would have divided its chromosomes into 23.3 Groups of Protists.

• In the past 20 years, genetic data has shown that make cilia/flagella can be a part of the life cycle.
• Many relationships were previously unclear because they had mitochondria from an aerobic mistake.
• The majority view is that all alpha-proteobacterium lived inside the cell.
• The host had a nucleus at the time of Amoebozoa, Opisthokonta, Rhizaria, and Chromalveolata.
• Excavata may have been the last common ancestor.
• The goal of this classification scheme is to create a cell wall for at least part of its life cycle, but more data are clusters of species that all are derived from a common needed to confirm this hypothesis.
• Today's eukaryotes are related.
• Many protists are parasites and can be identified.

• Protists destroy crops.

• There are 1n zoospores in the sporangia.

• The 2n plant is the sporophyte.

• The gametophyte is diploid.

• The macronuclei are derived from a plant.

• Sexual reproduction can cause meiosis and meosis.

• Monocercomonoides has no genes that are visible to the naked eye.

• The histones were wrapped around the volcanic activity chromosomes which were arranged in a linear fashion.
• There is a(n) Monocercomonoides.

• Mitochondria are most likely to have evolved.

• Protists with a pellicle are surrounded by redalga.

• The haploid form can be multicellular.

• The diploid form can be multicellular.

• Carbon fixation is an example.

• The amoeba E. histolytica can cause disease in people.
• It is most likely a metabolic classification.

• They fix carbon.

• They are the apex producer.

• Nitrogen cycles are produced by confinement between two Paramecia.

• The parts of the eukaryotes that are similar to Archaea.

• If a protist's environment changes, a light-sensitive eyespot might be useless.

• Giardia lamblia is a cyst-forming protist.

• Animals and fungi are included, as well as what type of environments might G. lamblia protists be in.