principles of biology
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Principles of Biology. By Frank H. Osborne, Ph. D. Lab 9 - The Cell Cycle. The G 1 , S and G 2 phases are all part of Interphase. Interphase. A. The G 1 Phase 1. The cell grows and doubles the number of cytoplasmic components. 2. The cell prepares for DNA synthesis. - PowerPoint PPT PresentationTRANSCRIPT
Principles of Biology
By
Frank H. Osborne, Ph. D.
Lab 9 - The Cell Cycle
The G1, S and G2 phases are all part of Interphase.
InterphaseA. The G1 Phase 1. The cell grows and doubles the number of cytoplasmic components. 2. The cell prepares for DNA synthesis.B. The S Phase 1. The cell synthesizes DNA. 2. Each chromosome develops a second chromatid.
C. The G2 Phase
1. The cell completes activities required for cell division.
2. The cell prepares to divide.
Phases of Mitosis
Interphase
Prophase
Anaphase
Telophase
Metaphase
Cell DivisionA. Mitosis 1. Mitosis is the division of the nucleus. 2. Phases of mitosis. a. Prophase i. This occurs first. (pro = pre) ii. The nuclear membrane disappears. iii. The nucleoli disappear. iv. The chromosomes shorten and thicken. v. The spindle forms.
Prophase
Spindle
spinning wheel
Spindle
b. Metaphase i. The chromosomes line up in the center (equator) of the spindle. ii. The centromere of each chromosome divides. iii. Each centromere is attached to a microtubule of the spindle.
c. Anaphase
i. The chromosomes are pulled toward the poles of the spindle.
ii. Each chromosome has one chromatid.
d. Telophase
i. The chromosomes have arrived at the poles of the spindle.
ii. The nuclear membrane is rebuilt
iii. The nucleoli reappear.
Mitosis in a plant cell
B. Cytokinesis 1. Cytokinesis is a division of the cytoplasm. 2. Cytokinesis begins as telophase ends.
Cells pinch here Cell plate
Cell DivisionC. Differences in cell division 1. Animal cells a. Animal cells need centrioles to help form the spindle. b. Animal cells pinch apart because they do not have cell walls.
Cell Division 2. Plant cells
a. Plant cells can form a spindle without centrioles.
b. Plant cells form a middle lamella during cytokinesis.
Cell DivisionD. Properties of cell division
1. There are two of each chromosome in each body cell.
2. Mitosis assures that each daughter cell has the same number of chromosomes as the mother cell.
3. Formation of reproductive cells is different.
The End
Lab 9
The Cell Cycle