Cell Division Mitosis replaces worn-out old cells with fresh new duplicates
Generates Replacements Cell divide to a. Grow (increase in size) b. Repair (cells must be replaced with they die) c. Reproduction (new offsprings) 1. Asexual reproduction (one parent) 2. Sexual reproduction (two parents Each time a cell reproduces, the new cells contain all the essential cytoplasm, organelles, and chromosomes needed for an organism to develop, survive, and function.
The cell cycle describes the series of phases that leads to cell division
First Growth Phase (G1) Interphase – part of the cell cycle that occurs between divisions G1, S, G2 G1: The cell’s primary growth phase. Normal cellular functions (making proteins, getting rid of waste, etc, take place.
2.Synthesis Replication (S phase) DNADNA is synthesis (S) –the cell begins preparations fordivision. Every chromosome creates an exact duplicate of itself in a process called replication Interphase – part of the cell cycle that occurs between divisions
Chromosome -compact X-shaped form of chromatin formed (and visible) during mitosis Chromatid - single arm of an X-shaped chromosome S- Synthesis/DNA Replication
Interphase part of the cell cycle that occurs between divisions (G1, S, and G2) 1.DNA appears like threadlike coils. 2.DNA coils to form Chromosomes which appear as threadlike coils (chromatin) at start. 3.Chromosomes are copied (# doubles). 4.Sister chomatids at end of this phase
3. Second Growth Phase (G2) Second period of growth and preparation for cell division Interphase = G1 + S + G2 Interphase – part of the cell cycle that occurs between divisions
4.Mitosis - The cell’s nucleus duplicates, then divides 5.Cytokinesis Cytoplasm divides, forming two daughter cells