Slide 1Mitosis: InterphaseProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokinesisSweat GlandsSlide 10Madeline (Mattie) [email protected] SESSION 3Mitosis: InterphaseThe cell is engaged in metabolic activity and performing its prepare for mitosis (the next four phases that lead up to and include nuclear division). Chromosomes are not clearly discerned in the nucleus, although a dark spot called the nucleolus may be visible. The cell may contain a pair of centrioles (or microtubule organizing centers in plants) both of which are organizational sites for microtubules.ProphaseChromatin in the nucleus begins to condense and becomes visible in the light microscope as chromosomes. The nucleolus disappears. Centrioles begin moving to opposite ends of the cell and fibers extend from the centromeres. Some fibers cross the cell to form the mitotic spindle.PrometaphaseThe nuclear membrane dissolves, marking the beginning of prometaphase. Proteins attach to the centromeres creating the kinetochores. Microtubules attach at the kinetochores and the chromosomes begin moving.MetaphaseSpindle fibers align the chromosomes along the middle of the cell nucleus. This line is referred to as the metaphase plate. This organization helps to ensure that in the next phase, when the chromosomes are separated, each new nucleus will receive one copy of each chromosome.AnaphaseThe paired chromosomes separate at the kinetochores and move to opposite sides of the cell. Motion results from a combination of kinetochore movement along the spindle microtubules and through the physical interaction of polar microtubules.TelophaseChromatids arrive at opposite poles of cell, and new membranes form around the daughter nuclei. The chromosomes disperse and are no longer visible under the light microscope. The spindle fibers disperse, and cytokinesis or the partitioning of the cell may also begin during this stage.CytokinesisIn animal cells, cytokinesis results when a fiber ring composed of a protein called actin around the center of the cell contracts pinching the cell into two daughter cells, each with one nucleus. In plant cells, the rigid wall requires that a cell plate be synthesized between the two daughter cells.Sweat Glands•Sudoriferous–Merocrine/eccrine•Most numerous in the palms of the hands, and soles of the feet•Least numerous in the neck and back•Exercise sweat•Watery substance that cools the body–Apocrine•Open into the upper portion of a hair follicle found in the axilla, groin and mammary areas•Smelly, anxiety sweat- bacterial waste products produce a characteristic odor (pheromones)•Associated with emotional stress or sexual excitement•Fluid is thicker than that produced by eccrine glands•These glands are larger than eccrine glands•Sebaceous/holocrine gland–Rarely found in the palms of the hands and soles of the feet–Abundant in the scalp, face, nose and mouth–Sebum released oils the hair and skin (greasy look)–Prevents the evaporation of sweat and aid the body in the retention of