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Chapter 18
Cell Biology
Term | Definition |
---|---|
Apoptosis | A tightly controlled form of program cell death that allows cells that are unneeded or unwanted to be eliminated from an adult or developing organism |
Stages of cell cycle | Interphase - 3 Phases: G1, S, G2 Mitotic (M) phase |
G1 Phase | Cell grows, copies organelles, makes molecular building blocks |
S Phase | Cell synthesizes a complete copy of DNA in nucleus, duplicates the centrosomes |
G2 Phase | Cell continues to grow, makes proteins and organelles, reorganizes and repairs its contents in preparation for mitosis |
S Phase | Cell synthesizes a complete copy of DNA in nucleus, duplicates the centrosomes |
G2 Phase | Cell continues to grow, makes proteins and organelles, reorganizes its contents in preparation for mitosis |
Mitotic (M) phase | Cell divides the copied DNA and cytoplasm to make two new cells Two processes: mitosis and cytokinesis |
Mitosis | DNA of the cell condenses into visible chromosomes and pulled apart by the mitotic spindle. 4 stages: prophesy, metaphase, anaphase, telophase |
Cytokinesis | The cytoplasm is split in two making two new cells, begins just as mitosis is ending, in anaphase or telophase |
Prophase - early, late | Early- mitotic spindle forms, chromosomes condense, nucleolus is gone Late- nuclear envelope breaks down, chromosomes fully condensed |
Metaphase | Spindle captures all chromosomes and line up at metaphase plate (middle of the cell) |
Anaphase | Sister chromatids separate and are pulled to opposite ends of the cell, microtubules push poles apart elongating the cell |
Telaphase | Chromosomes decondense, spindles disappear, nuclear membrane reforms, nucleolus reappears, two new nuclei form (one for each set of chromosomes) |