THE CELL CYCLE FUNCTIONS The cell cycle is

THE CELL CYCLE

FUNCTIONS The cell cycle is the regular sequence of growth and division that cells undergo as they live life and divide to make new cells. The length of the cell cycle depends on the type of cell Cell division has three functions: growth, repair of damage and reproduction

HOW DO CELLS REPRODUCE? • Cells reproduce ASEXUALLY: one parent cell divides and makes two copies of itself • The goal of asexual reproduction is to produce daughter cells that are GENETICALLY IDENTICAL to the parent cell

WHAT HAPPENS? ? During the cell cycle, cells grow, prepare for division and divide into two new cells, which are called DAUGHTER CELLS There are three main stages to the cell cycle: INTERPHASE MITOSIS CYTOKINESIS

DIAGRAM OF THE CELL CYCLE

WHAT HAPPENS TO THE DNA? ? ? during interphase, the DNA is relaxed in the form of CHROMATIN (dna and proteins) during mitosis, the CHROMATIN coils up tightly into a structure called a CHROMOSOME( or SISTER CHROMATID) after division, it goes back to CHROMATIN

STAGE I: INTERPHASE PREPARING TO DIVIDE The first stage of the cell cycle is INTERPHASE Cells spend most of their time in INTERPHASE. During this stage, they are growing, living their life and preparing to divide. This process has three steps to it: • G 1 - cell grows and lives • S- makes a copy of the DNA • G 2 - fixes mistakes in the DNA copy and prepares to divide

STAGE TWO: MITOSIS DIVIDING THE NUCLEAR MATERIAL THE SECOND STAGE OF THE CELL CYCLE IS MITOSIS IS THE PROCESS THAT DIVIDES THE NUCLEAR MATERIAL MITOSIS IS MADE UP OF FOUR PHASES: PROPHASE METAPHASE ANAPHASE TELOPHASE

PROPHASE During PROPHASE, the cell begins to prepare to divide the nuc • • The CHROMATIN condenses into CHROMOSOMES The centrioles move to opposite ends of the cell Spindle fibers begin to grow from the centrioles The nuclear membrane dissolves

METAPHASE During metaphase, A spindle fiber attaches to each CHROMOSOME at the CENTROMERE the SISTER CHROMATIDS are moved to the middle of the cell and line up on the equator of the cell

ANAPHASE During ANAPHASE, the centromere holding the sister chromatids together splits. Each chromosome is pulled to opposite ends of the cell by their attached spindle fiber

TELOPHASE During TELOPHASE, the chromosomes reach the opposite ends of the cell, where two nuclear membranes form around set. The cell starts to form the cleavage furrow Chromosomes relax back into chromatin

CYTOKINESIS is the process that divides the rest of the cell. During cytokinesis, the cell membrane completes it’s split and the cytoplasm of the cell is divided to form two new daughter cells, which are EXACT COPIES of the parent cell