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Lecture 12 (MT2)
BIO 201.01
22
Biology
Undergraduate 1
03/18/2013

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Term
Miller and Urey's later experiments found that ___ (five things) could also be formed under premordial soup conditions.
Definition
vitamin B12, sugar, NAD, lactic acids and fatty acids
Term
Since the Miller and Urey experiments, is has been determined that ___ (four things) may have also been in the atmosphere in prebiotic times.
Definition
carbon dioxide, nitrogen, sulfur dioxide and sulfite
Term
The ___ revolves around the basis that silica crystals in solution "reproduce" into daughter molecules with imperfections.
Definition
clay theory
Term
The ___ theory revolves around the idea that lipids formed protocells which allowed life to begin.
Definition
lipid world
Term
___ is a theory that meteors supplied complex polymers from space for Earth.
Definition
Exogenesis
Term
___ is the idea that life arrived on Earth from meteors (through transpermia - life surviving space travel in meteros).
Definition
Panspermia
Term
There is evidence for exogenesis. In 1969, an Australian meteor was found to have ___ (four things).
Definition
purines, pyrimidines, sugars and amino acids
Term
An example suggesting that panspermia is valid was found in the 1984 meteor 84001, found in Antarctica. It was found to contain ___ (three things).
Definition
water, polycyclic aromatic compounds and magnetite (iron oxide produced from living beings), Scientists think that the magnetite could have protected the interior of the metior from going above 40 degrees F.
Term
There are two hypothesis concerning the early world. One suggests that metabolism, chemical changes, preceeded nucleic acid and protein replication. The other suggests the opposite, that nucleotides appeared and were able to reproduce. Two problems with the latter theory is that ___.
Definition
nucleic acid polymers have not been observed in prebiotic conditions, DNA is not self catalytic
Term
RNA is believed to have come before DNA, because ___ (three things).
Definition
RNA is capable of forming many complex structures, protein synthesis uses RNA, viruses use RNA
Term
Viruses enter the cell and insert their viral RNA into the host's genome through a process called ___, with the help of the enzyme ___.
Definition
reverse transcription, reverse transcriptase
Term
The solar system began to form around ___bya, and life on Earth began to show up around ___bya.
Definition
4.6, 3.5
Term
Stromatolites are fossil-like structures formed by ___-like organisms. Some of these structures date back as early as 3.5bya.
Definition
cyanobacteria
Term
Thanks to marine photosynthetic bacteria, a lot of oxygen was brought into the atmosphere over a period of 1-2 billion years. The atmosphere eventaully developed into (approx.) ___% nitrogen, ___% oxygen and ___% argon. There are other trace molecules present.
Definition
78%, 21%, 1%
Term
Eukaryotes appeared in fossil record about ___ billion years after prokaryotes. This means the earliest eukaryote fossil is dated about 1.2 billion years old.
Definition
2.3
Term
The three domains of life: prokaryotes, archaea and eukaryotes have ___ (four things) in common.
Definition
glycolysis, transcription and translation, plasma membranes and ribosomes
Term
Archaea are more closely related to ___ than ___.
Definition
prokaryotes, eukaryotes
Term
There are many difference between prokaryotes and eukaryotes. Prokaryotes do not have a "normal"  ___skeleton, do not divide by ___ (they use binary fission), do not have a ___, have DNA in a ___ shape, do not have ___-enclosed organelles (but they do have cristae).
Definition
cyto-, mitosis, nucleus, circular, membrane
Term
There are about 3E28 total bacteria and archaea cells in the ocean. Most bacteria are unicellular (although there are some multicellular forms). The most common forms of bacteria are ___ (three forms).
Definition
cocci (nuggets), bacilli (rods) and helices (string)
Term
Prokaryotic cell walls are ___ as/from plant, algae and fungal cell walls
Definition
different
Term
Gram staining is when bacteria cells are subject to purple dye followed by iodine, and then washed with alcohol and a red counterstain. A bacteria is gram-___ if they have a thick, dense cell wall made up of peptidoglycan. Contrary, if they have a small peptidoglycan wall, they are gram-___.
Definition

positive, negative

 

In a gram-positive cell, after the purple dye and iodine is absorbed, the washing of alcohol and addition of red dye will not interfere; they will remain dyed purple. For gram-negative cells, which did not absorb the purple dye to begin with, they will uptake the red dye and appear pink.

Term
Bacteria move in a multitude of ways. They may use flagella (different from eukaryotes), but can also use axial filaments to create ___ movement. Some may use ___, which allow up and down movement in water.
Definition
spiral, gas vesicles
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