Chapter 28 protists

Chapter 28 protists - Chapter 28: Protists -Domains:...

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Chapter 28: Protists --Domains: Bacteria, Archaea, Eukarya --Eukarya incluce algae, plants, fungi, animals, protists—all eukaryotes that aren’t plants, fungi, animals. --Eukaryote characteristics: nuclear envelope, nucleus, organelles, mitosis, cytoskeleton, histones (archaea have this too—DNA and proteins wrapped) reproduce via meiosis and mitosis (bacteria and archaea use fission) multicellular (no multicellular archaea and rate in bacteria) --Protists are paraphyletic —represent some, but not all of the descendants of a common ancestor --no synamorphies —there is not trait that is found only in protests. --VERY diverse, but one commonground is that they are usually found in water I.Why study protests? A. i. P. infestans parasite causes Ireland potato famine ii. Plasmodium causes Malaria 1. Four species of this protest can infect and cause Malaria 2. It spends part of its life cycle in mosquitoes, so insecticides are used. However, natural selection favored mosquito strains resistant to them. 3. Plasmodium can evolve resistance to drugs used to treat Malaria in people also. Vaccine hard to develop bc it evolves so quickly iii. Harmful algal blooms —photosynthetic protests that grow rapidly and densely populate a marine area and release toxins. 1. Ex) dinoflagellates can cause “red tides” because they have a lot of red accessory pigments. 2. Harmful bc shellfish like clams filter photosynthetic protests as food, and toxins build up in their flesh. If eaten, it is poisonous. (but the shellfish isin’t harmed)D B. Ecological importance i. There aren’t many types of named protest species(when compared to the types of other Eukaryotes), but they are abundant on earth in number. This makes them ecologically important ii. Protists play a key role in aquatic food chains : 1. Primary producers —species that produce chemical E from light E. Many primary producers are protists. (They take CO 2 and reduce it to sugar or other organic compounds w high potential E) A. Ex) plankton —small organisms living near water surfaces; phytoplankton photosynthetic plankton; (These are the basis of food chains in water environments) B. Primary producers are at the bottom of the food chain, and are consumed by primary consumers. 2. Without protists food chains in watery environments would probably collapse iii. Protists may help global warming —high CO 2 levels in atmosphere that trap heat from the earth going back out to space.D 1. global carbon cycle —the movement of carbon atoms from carbon dioxide molecules in the environment to organisms on earth, then back to the atmosphere.
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2. To fight global warming, we can try to increase the amt of carbon stored on earth, and decrease it in the atmosphere. The following may be some solutions: A. 1) Wood stores carbon for a long time, so plant trees B. 2) Fertilize the ocean with iron for photosynthetic protists and bacteria (this method is debated—explained below):
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Chapter 28 protists - Chapter 28: Protists -Domains:...

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