Cell Division and DNA Replication (Chapter 4, section 3 &4)
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Cell cycleX
Reason for cell cycle-
Stages of the cell cycle-
Interphase-
NOTES WRITTEN
Cell cycle- growth, replication, and division of cells (making new cells)
1. Reproduction
2. Growth
3. Repair
1. Interphase
2. Mitosis (prophase, metaphase, anaphase, telophase)
3. Cytokinesis
Cells grow in size, make a copy of DNA and organelles, and prepare
for cell division
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Mitosis (four steps)-
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Cytokinesis-
Longest part of cell cycle
1. Prophase- chromosomes (coiled DNA) become visible and
nucleus starts to break down
2. Metaphase- chromosomes line up in the middle of the cell
3. Anaphase- chromatids (identical copies of DNA) separate to opposite
ends
4. Telophase- chromosomes unwind, nucleus forms
Cytoplasm divides becoming two individual cells
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Animals- cell membrane pinches into two cells
Plants- cell wall forms between the two cells
Cell cycle acronym-
I Play Music At The Club
DNA-
DNA (deoxyribonucleic acid)- genetic material that contains all the
instructions to build and maintain an organism
DNA replication (copying DNA) allows each cell to have the same exact copy
of DNA
SUMMARY
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NOTES WRITTEN
DNA vocabularyX
DNA structure-
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Chromatin- long DNA strands
Chromosome- coiled DNA
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Chromatid- identical copies of DNA
Double helix (twisted ladder)
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Four DNA bases-
‘Sides’- sugar and phosphate
‘Rungs’- nitrogen bases
Adenine (A)
Cytosine (C)
Guanine (G)
Thymine (T)
Base pair rules-
DNA replicationX
A-T (adenine always pairs with thymine)
C-G (cytosine always pairs with guanine)
1. DNA unwinds and separates (unzips)
2. Bases are added on to each original DNA strand
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Identical copy of the DNA is made (half the strand is old, half is new)
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Occurs during interphase
Differentiation-
Not all cells are alike, not all cells have the same function in multicellular
organisms. Cells that have different functions look different from each
other
Differentiation- process by which cells change structure and become
different
When and how it changes depends on an organisms’ DNA
Stem cells-
Animal cells have stem cells (cells that can differentiate throughout life)
but most cells cannot change into another type of cell after differentiation
SUMMARY
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