BioExam8-14 - Bio Exam III Chapters 8-14 Cell Cycle a...

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-1Bio Exam III Chapters 8-14 Cell Cycle - a series of events from one cell division to the next. It begins when a new daughter cell forms by mitosis and cytoplasmic division; it ends when the cell divides. Mitosis, cytoplasmic division, and then interphase constitute one turn of the cycle. Interphase - the longest portion of the cell cycle. The cell increases in mass, roughly double the number of its cytoplasmic components, and duplicates its DNA. Divided into 3 stages: G1 - Interval (gap) of cell growth and functioning before the onset of DNA replication. S - Time of "synthesis" (DNA replication) G2 - Second interval (gap) after DNA replication when the cell prepares for division. Cell Division Mitosis - the nuclear division mechanism that occurs in somatic (body cells) of multicelled eukaryotes. It is the basis of increases in body size during growth, replacements of worn-out or dead cells, and tissue repair. 1. Prophase - the cell's chromosomes are already duplicated, with sister chromatids joined at the centromere. They condense into thick, rod like forms. 2. Metaphase - They line up at the center. 3. Anaphase - The chromatids split and begin to move towards the opposite poles 4. Telophase - starts when each chromosome reaches the poles. There are two clusters of chromosomes, which decondense. A new nuclear envelope forms. Meiosis - functions only in sexual reproduction, and it precedes the formation of gametes. - reduces the chromosome number in half -eukaryotic cells - Makes gametes/spores (sperm and egg) 1. Prophase I - thread like chromosomes are duplicated and start to condense. Each pair swap a segment (crossing over). The nuclear envelope starts to break down. 2. Metaphase I - The chromosomes are aligned across the center of the cell. 3. Anaphase I - The chromosomes are split.
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BioExam8-14 - Bio Exam III Chapters 8-14 Cell Cycle a...

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