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22 Cards in this Set
- Front
- Back
What are the 4 reasons cells divide?
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1. Too big (s.a. to volume ratio is small)
2. To replace dead/damaged cells 3. For growth + development 4. DNA overload |
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What is DNA's sugar?
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Deoxyribose
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What are the nitrogen bases?
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Purines (2 rings) adenine, guanine
Pyrimadines (1 ring) thymine, cytosine Adenine ---> Thymine Guanine ---> Cytosine |
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How are the nitrogen bases held together?
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By weak hydrogen bonds
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What did Chargaff do?
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Found that nitrogen bases had base pairing rules
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What did Wilkins & Franklin do?
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Found that DNA is shaped like a double helix
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What did Watson & Crick do?
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Won Nobel Prize for DNA structure
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What did Griffith do?
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Discovered the transforming factor/principle
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What is interphase?
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A time of growth and development
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What happens in G1?
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Growth
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What happens in the S phase?
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DNA replicates (46 ---> 92)
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What happens in G2?
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Growth organelles replicate and prepare to divide
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What happens in M phase, mitosis?
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The nucleus divides (92 ---> 46)
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What happens in prophase?
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-The nuclear membrane dissolves
-Spindle fibers form |
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What happens in metaphase?
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Chromosomes line up in the middle of cell
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What happens in anaphase?
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Chromosomes are pulled apart
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What happens in telophase?
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-Nuclear membrane reforms
-Spindle fibers fall apart, chromosomes uncoil |
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What is cytokinesis?
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Division of cytoplasm
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What is cleavage furrow?
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Cytokinesis for animal cells
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What is cell plate?
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Cytokinesis for plants
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What kind of reproduction is mitosis?
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Asexual
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What are the steps of DNA replication?
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1. Unzip DNA w/ enzyme helicase
2. DNA polymerase brings in complimentary bases 3. Ligase zips it back up |