Standard SC.912.L.15.6_Classification
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Classwork/ Homework ActivitiesPractice QuestionsKingdom Profile Project |
Finding Order in Diversity
- There are eight levels of classification: Kingdom, Phylum, Class, Order, Family, Genus, and Species. They are hierarchically organized as follows.
Organisms have been classified according to their visible characteristics for a very long time,as scientist were able to discover features that otherwise were not visible with the naked eye, classification schemes changed, until more recently where biochemical analysis (like DNA testing) help scientist figure out more complex relationships.
Prokaryotic cell: members of Archaea and Bacteria
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Eukaryotic cell: members of the Domain Eukarya
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Prokaryotes
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They both have basic structures such as:
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Eukaryotes
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Domain Bacteria:
Kingdom Eubacteria:
Cell Structure:
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Common pathogenic bacteria and the types of bacterial diseases they cause include:
- Streptococci which causes strep throat.
- Escherichia coli and Salmonella cause food poisoning.
- Helicobacter pylori cause gastritis and ulcers.
- Neisseria gonorrhoeae causes the sexually transmitted disease gonorrhea.
- Neisseria meningitidis causes meningitis.
However, some bacteria also help produce many antibiotics (genetic engineered), vitamins and yogurt.
Domain Archaea:
Archaea is derived from the Greek word archaios, meaning “ancient” or “primitive”
- As you can see in the diagram below, Archaea and Eukarya share a common ancestor more recently than they did with bacteria, so they are more related.
- Archaea also transfer genes similar to a eukaryote, and they have a different genetic history than bacteria.
Cell Structure:
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Mode of Nutrition:
- Photosynthetic: Use carbon dioxide and light to make sugars.
- Autotroph (Make their own food):
- Photosynthetic: Use carbon dioxide and light to make sugars.
- Heterotroph: Some feed of other organisms
- Can live without oxygen
Archaea is considered to be "Extremophiles", which means they thrive under extreme conditions, in environments that are hostile to all other forms of life.
- Thermophile: Pyrolobus fumarii, which holds the upper temperature limit for life at 113 °C (235 °F) and was found living in hydrothermal vents.
- Halophiles: use to survive in high concentrations of salt
- Acidophiles and alkaliphiles, organisms tolerating high acidic or basic pH values, respectively. Species of Picrophilus, which were isolated from acidic soils in Japan and are the most acid-tolerant organisms known—capable of growth at around pH 0.
- Barophiles, organisms that grow under high pressure;
- Methanogens: Use elemental hydrogen (H2) to reduce carbon dioxide into methane. They are obligate anaerobes (cannot live in the presence of oxygen), therefore are found in anaerobic environments, such as in marshes, hot springs, and the guts of animals, including humans. They are important as decomposers in sewage treatment plants. Not all archaea produce methane, but they are the only creatures that can – it’s one of the differences that sets them apart from the other two domains of life.
Domain Eukarya:
Because of its large diversity, member of the domain Eukarya may include the following characteristics:
- Eukaryotic: Have a nucleus and organelles
- Unicellular or multicellular
- Autotroph or Heterotroph
- Reproduce sexually or asexually
- Include 4 kingdoms
Protista
Members of the domain Protista would not fit in any of the other groups, thus they are considered the "outcasts". These are further divided into:
A) "Animal-like" Protista (Protozoa):
A) "Animal-like" Protista (Protozoa):
- Unicellular
- Heterotroph
- Animal-like protists are distinguished from other protists because of their ability to move and catch food. They move using amoeboid cytoplasmic flow, cilia, or flagellum.
B) "Plant-Like" Protista:
- They have many plant-like features but are not true plants; because they lack true tissues, organs, or any cellular specialization.
Animalia