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32 Cards in this Set
- Front
- Back
describe the conditions of primordial earth
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covered with lava lots of meteorite bombardmentstook 500 million years for earth to cool down |
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living organisms lived how many years ago
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3.75 billion years ago
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oldest bacteria fossils have been found are how many years ao
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3.4 billion years ago
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what are the 5 steps for the origin of life by abiogenesis
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1) organic monomers form inorganic molecules 2) monomers linked together to form polymers 3) enclosing of organic molecules into membrane bound protobionts 4) RNA was the initial information storage but then DNA came later 5) establishment of energy forming pathways to bring in energy to sustain life |
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how were organic molecules that are necessary to support life originate to primordial eath
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were formed de novo on earth itself
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how were monomers first formed
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spontaneously formed in shallow oceans
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what was the Oparin-Haldane hypothesis
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a reactive atmosphere with electrons and hydrogens nessisary to convert inorganic into C02 and then into organic carbons
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how did polymers come from monomers
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the oceans turned into "prebiotic soup" and then uv light from the sun formed the polymers
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Stanley Miller created the Miller-Urey experiment to test which theory what was his experiment |
the Oparin Haldane theory *he simulated lightening and proved its possible to produce organic molecules spontaneously from inorganic precursors. |
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what is the formula for atmosphere
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CO CO2 N2 H20
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what were some problems of the Miller-Urey experiment
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the intensity of the energy was too high he used the wrong formula for atmposhpere. lol
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How did RNA form into DNA
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by genetic mutations
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differences between RNA and DNA
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DNA is more stable, has enzymes, double helix RNA less stable, has ribosomes (slower than enzymes as catalysts), single helix |
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how long ago was the first "primitive organism"
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3.4 billion years ago
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what are Stromatolites
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formed by cyanobacteria. they were layered accretionary structures formed in shallow seas.
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describe mitosis and give a brief description of each
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prophase: tightly condenses chromosomes Prometaphase: nucleaur envelope dissociates, spindle apparatus moves to where the condensed chromasomes are located metaphase: the chromosomes line up in the middle Anaphase: the chromosomes split apart Telophase: chromosomes decondense |
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when is meiosis used instead of mitosis
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meiosis is used in the division of diploid cells to haploid cells
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describe the process of meiosis
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Interphase I: G1, S, and G2 phase to prepare for the division Prophase I: synapiss and crossing over occur, along with condensing Metaphase I: Lines up in the middle Anaphase I: chromosomes are pulled apart Interkinesis: cells prepare to divide again but do not replicate Prophase II: condense Prometaphase II: same as mitosis metaphase II: line up in middle Anaphase II: pulled to opposite poles telophase: daughter cells are haploid, chromosomes consist of 2 chromosomes |
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a haploid cell + haploid cell = what cell
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diploid cell
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how does the spindle form in animal cells
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the centrosome splits in 2 and the centrosome controls the spindle
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how does the spindle form in plant cells
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(plant cells lack centrosomes) they use Microtubule Organizing Centers (MTOC)
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what is a kinetochore microtubule
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area on the chromatids where the spindle fibers attach to during cell division so they can pull them apart.
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where are sister chromatids held together
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At the centromere
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when does the metaphase stage end
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when the sister chromatids start to split
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what does the cleavage furrow do
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divides the cell into 2
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what is synapsis
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the process of homologous chromosomes finding each other and pairing up to form bivalents
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what is crossing over
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the exchanging of genetics between two bivalents. (after crossing over the arms separate but still remain stuck resulting in a x shaped chiasmata)
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what does crossing over create
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a new genetic variation
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why do the chromosomes along the metaphase plate (middle) line up randomly
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produces different mixes of chromosomes resulting in genetic variation
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2n= how many chromosomes
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2n=46
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n=?
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23. n=23. n stands for 23. so 2n= 23+23 which equals 46.
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