types of life

prokaryote

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• Unicellular organism who lacks membrane bound organelles
• DNA not in a nucleus, it just floats around in cytoplasm
• much smaller than eukaryotic cells
• a prokaryote is about the size of a mitochondria in a eukaryote 
• single DNA loops

Bacteria and Archaea are prokaryotes, the two domains of prokaryotic life.

There are many types of bacteria: 

• Cyanobacteria are a phylum of bacteria that obtain their energy through photosynthesis and are the only photosynthetic prokaryotes able to produce oxygen.
• Round bacteria are referred to as cocci (singular: coccus),
  • an example is Streptococcus
• ​Cylindrical, capsule-shaped bacteria are named bacilli (singular: bacillus),
  • bacteria that make yogurt: Lactobacillus bulgaricus 
• Spiral bacteria are called spirilla (singular: spirillum)
  • ​Lyme disease and syphillis are caused by this type of bacteria

​Bacteria equipment:

• Flagella: whip-like appendages used to move around, like arms
• Pili: short, hair-like appendages extending from the surface, used to stick to surfaces
• Capsule: sticky coating, used to stick to surfaces

Some but not all bacteria are pathogens: a disease causing agent

Some bacteria are purely beneficial and help with symbiosis: the relationship in which two different organisms live together, often interdependently. 

Nitrogen Fixation:

• Converting atmospheric nitrogen into a form that plants can use to grow
  • ​Two types of bacteria do this job: non-symbiotic bacteria in the soil and symbiotic bacteria that live in the roots of plants.
  • Bacteria in the genera Clostridium and Azotobacter are non-symbiotic nitrogen-fixing bacteria.
  • The genus Rhizobium are symbiotic bacteria.

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Archaea

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The other domain of prokaryotic life, tend to live in extreme environments

Grouped according to where they live (pg 371):
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• Halophiles: live in very salty places
• Hyperthermophile: extremely high temperatures (80 to 100 Celcius), (176 to 212 Fahrenheitt) ​

Archaea in hydrothermal vents:

The sea floor is an anaerobic environment, no oxygen

• Serpentinization: H2, hydrogen is formed when mantle rock is exposed to seawater, the rock columns that are formed as gases emerge from the earth's crust in hydrothermal chimneys

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• Methanogens: archaea that produce methane as a by-product of converting energy from carbon dioxde, using hydrogen H2 as an energy source

  

• Anaerobic Archaea: eat methane

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endosymbiosis

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Evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms.

That prokaryotes ate a mitochondria and kept it around, some ate a chloroplast and became plants (pg. 391)

Endosymbiotic theory deals with the origins of mitochondria and chloroplasts, two eukaryotic organelles that have bacteria characteristics. Mitochondria and chloroplasts are believed to have developed from symbiotic bacteria, specifically alpha-proteobacteria and cyanobacteria, respectively.
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​Mitochondria: an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner layer being folded inward to form layers (cristae).

Makes ATP

Mitochondria origin: The endosymbiotic hypothesis for the origin of mitochondria (and chloroplasts) suggests that mitochondria are descended from specialized bacteria (probably purple nonsulfur bacteria) that somehow survived endocytosis by another species of prokaryote or some other cell type, and became incorporated into the cytoplasm.

SO Mitochondria and Chloroplasts were bacteria billions of years ago.

They have their own DNA 

Mitochondria and chloroplasts have striking similarities to bacteria cells.

• They have their own DNA, which is separate from the DNA found in the nucleus of the cell.
• And both organelles use their DNA to produce many proteins and enzymes required for their function.

Mitochondrial DNA (mtDNA or mDNA): is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP).

Mitochondrial DNA is double-stranded like cellular DNA in prokaryotes. However it is circular and similar in size and structure to the single DNA loops found in prokaryotes like bacteria.

Mitochondria and Chloroplasts can no longer live outside the eukaryotic cell, and cells cannot live without mitochondria or chloroplasts because that is how they get ATP.

Over millions of years of evolution, mitochondria and chloroplasts have become more specialized and today they cannot live outside the cell.

They are now interdependent/codependent  

Cells would only be able to obtain energy from anaerobic respiration (in the absence of oxygen)

So mitochondria helped get archaea out of the hydrothermal vents

Evidence obtained so far indicates that the Bacteria and Archaea diverged from a common ancestor about 3.7 billion years ago, and somewhat later the Archaea diverged from the lineage that would become the Eukarya.
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• Evidence was found by comparing nucleic acid sequences to discover the evolutionary relationships among microorganisms.
• The more alike the rRNA sequences were between two microbes, the more recently they shared an ancestor.
• Read more: http://www.biologyreference.com/Ar-Bi/Archaea.html#ixzz5cZWeYzkr

Around 2 billion years ago, archaea and bacteria found a way to share genes or merge some of their material and a third kingdom of life, eukaryotes, was born.

Mitochondria know both aerobic and anaerobic respiration: When oxygen is present, the mitochondria will undergo aerobic respiration which leads to the Krebs cycle.

• However, if oxygen is not present, fermentation of the pyruvate molecule will occur.

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eukaryote 

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• An organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus.
• Eukaryotes include all living organisms other than the eubacteria and archaebacteria.

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​so plants, protists, fungi, and animals

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plants

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A multi cellular eukaryote that has cell walls, carries out photosynthesis, and is adapted to living on land 

Types of plants:​

• Bryophyte: a non-vascular plant that does not produce seeds

Vascular plant: plant with tissues that transport water and nutrients through the plants body. Xylem and Phloem.

• Fern: the first vascular plants, do not produce seeds

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• Gymnosperm: seed-bearing plant with "naked" seeds, usually in cones

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• Angiosperm: seed-bearing plant with seeds in a case, a fruit

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protists

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• A protist is any eukaryotic organism that is not an animal, plant or fungus. 
• Single cell, but with organelles
• Algae is an example, a photosynthetic protist
• Also Amoeba, Euglena, Paramecium,  
• Are a very diverse group of organisms. They are basically all the organisms that don't fit into the other groups. 

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monera

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• ("single", "solitary") is a kingdom that contains unicellular organisms with a prokaryotic cell organization (having no nuclear membrane), such as bacteria.

• A major difference between monerans and protists lies in the nucleus, which is the "command center" of a cell. Monerans do not have a true nucleus, while protistshave nuclei bound in their own nuclear membranes. 

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fungi

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• Includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. 
  • ​Yeast: single-cell fungi, in bread, in fermented beverages
    
  • Molds: form mycellia mats and hyphae, create a network in the soil.  help plants receive nutrients or retain moisture/ sometimes hurt the plant/ balance is key.
    
  • Mushrooms: the above ground fruiting body that releases spores, decay leaf litter and other plant matter, provide food for animals
    

• Unicellular or multicellular eukaryotic organism that obtains nutrients by secreting digestive enzymes into organic matter and absorbing the digestive product
• Decomposer: uses the organic substances in dead organisms to as sources of nutrient and energy. 
• Hypha/ Hyphae is plural: a long, threadlike structure through which fungi absorb nutrients 
• Mycellium: a spreading mass of interwoven hyphae, underground when you see a mushroom

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animals

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The six main groups are: invertebrates, mammals, birds, amphibians, reptiles and fish.

​Invertebrate: no spine​
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• SPONGES. 
• CNIDARIANS. 
• WORMS.
• ECHINODERMS.
• ARTHROPODS. 

​Arthropod: an invertebrate having a segmented body, a hard exoskeleton, and jointed appendages
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• Insects
• Arachnids
• Crustaceans
• Myriapods= Chilopoda, Diplopoda

Exoskeleton: a hard external skeleton, usually made of chitin protein

Endoskeleton: a solid internal skeleton, found in many animals

Insect: a six-legged arthropod with three body segments, head, thorax and abdomen
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Mammal: an animal with mammary glands and fur
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Birds: a warm-blooded egg-laying vertebrate distinguished by the possession of feathers, wings, and a beak and (typically) by being able to fly.
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Amphibians: a cold-blooded vertebrate animal of a class that comprises the frogs, toads, newts, and salamanders. They are distinguished by having an aquatic gill-breathing larval stage followed (typically) by a terrestrial lung-breathing adult stage.
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Reptiles: a cold-blooded vertebrate animal of a class that includes snakes, lizards, crocodiles, turtles, and tortoises. They are distinguished by having a dry scaly skin and typically laying soft-shelled eggs on land.
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Fish: a limbless cold-blooded vertebrate animal with gills and fins and living wholly in water.

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