Biology ch. 16
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Created by:
mayamoon17 on April 12, 2012
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62 terms
Terms | Definitions |
|---|---|
 4.6 b.y.a. | When did Earth form? |
| the "big bang" | broke up single mass of matter |
| 15 b.y.a. | when was the "big bang"? |
| oxygen | When life began, there was no _________ in the atmosphere. |
| water vapor in the atmosphere condensed | the first seas were formed by... |
| stromatolites | fossilized prokaryotes |
| 3.5 b.y.a. | stromatolites date back to... |
| 2.7 b.y.a. | oxygen accumulates in atmosphere (how many years ago?) |
| 2.1 b.y.a. | 1st fossil evidence of eukaryotes (how many years ago?) |
| 1.2 b.y.a. | 1st evidence of multi-cellular eukaryotes (how many years ago?) |
| 500 m.y.a. | all life was still aquatic (how many years ago?) |
| Pasteur | life comes from preexisting life |
| abiotically | Organic molecules may have been formed __________ in the conditions on early Earth. |
| 1st stage in the sequence of how life could have formed | small, organic molecules (amino acids; nucleotides) formed from simpler inorganic molecules in environment |
| 2nd stage in the sequence of how life could have formed | small organic molecules joined together into larger polymers such as proteins and nucleic acids |
| 3rd stage in the sequence of how life could have formed | molecules that could copy themselves (RNA) provided a basis for the inheritance of nuclear info |
| 4th stage in the sequence of how life could have formed | organic molecules became packaged within membranes and separated from their surroundings, forming pre-cells (what stage?) |
| protobiont | pre-cells |
| could have arisen on a lifeless earth | Stanley Miller's experiments showed that organic molecules... |
| amino acids, sugars, lipids, and the nitrogenous bases found in DNA and RNA | in Miller's experiment, lab stimulations produced... |
| hot rocks or clay | The first polymers may have formed on... |
| RNA | The first genetic material and enzymes may both have been... |
| RNA molecules | the first genes were... |
| preceded the first cells | Membrane-enclosed molecular cooperatives may have... |
| the formation of polypeptides | RNA might have acted as templates for... |
| RNA replication | polypeptides assist... |
| prokaryotes | the oldest life forms are... |
| bacteria and archaea | the two main branches of prokaryotic evolution |
| of nucleotide sequences and other molecular and cellular features | how are the domains bacteria and archaea distinguished from each other? |
| shapes | Prokaryotes come in a variety of |
| Spheres (cocci); Rods (bacilli); Curves or spirals | Prokaryotes may be shaped as... |
| chains and clusters | 2 different kinds of spheres (cocci) |
| steptococci | chains |
| staphylocci | clusters |
| comma shaped; helical; long/flexible | 3 types of curves/spirals |
| vibrios | comma shaped |
| spirilla | hellical |
| spirochetes | long, flexible cells |
| cell wall | maintains shape and provides protection |
| gram-positive and gram-negative; gram staining | two types of cell wall; determined by __________. |
| gram staining | ... |
| gram-positive | simpler cell wall; thick layer of pepitoglycan |
| gram-negative | more complex cell wall; less pepitoglycan and additional outer membrane |
| pili | used for the prokaryotes to stick to rocks, each other, ect. |
| flagella | enable prokaryotes to move |
| binary fission | reproduction of prokaryotes |
| endospores | enable the prokaryote to withstand harsh conditions |
| endospores | form a thick, protective coat, dehydrates, and becomes dormat |
| bacilius anthracis | example of endospore |
| autotrophs | make their own organic compounds from inorganic sources |
| photoautotraphs | harness sunlight for energy and use CO2 for carbon |
| chemoautotrophs | obtain energy from inorganic chemicals instead of sunlight |
| heterotrophs | obtain their carbon atoms from organic compounds |
| photoheterotrophs | can obtain energy from sunlight |
| chemoautotrophs | are so diverse that almost any organic molecule can serve as food for some species |
| biofilms | In some prokaryotes, metabolic cooperation occurs in surface-coating colonies called... |
| extremed environments | Archaea thrive in... |
| Salt lakes, acidic hot springs, deep-sea hydrothermal vents | archaea ar common in... |
| oceans | Archaea are also a major life-form in... |
| pathogenia | bacteria that cause disease by producing poisons |
| exotoxins | secreted by bacteria |
| endotoxins | components of outer membrane of gram-negative bacteria |
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