Biology Cell Division

• Rudolf/Rudolph Virchow - a German scientist who stated that every cell originates from another existing cell
• Binary Fission - the process by which prokaryotes produce new individuals that are genetically identical to the parent organism.
• Mitosis & Meiosis - two types of cell division
• Mitosis - occurs in somatic cells (body cells). This means that it takes place in all types of cells (skin, muscles, lungs, gut, and hair cells) that are not involved in the production of gametes (sex cells).
• Meiosis - is the type of cell division for the production of gametes in sexual reproduction.
• Cell division - process in which one cell, called the parent cell, divides to form two new cells, referred to as daughter cells.
• Nucleus - controls the center of the cell and contains DNA (replicate prior to cell division).
• Deoxyribonucleic Acid (DNA) - double-stranded nucleic acid that is tightly coiled .around proteins called histones, to form chromosomes
• Nucleotide - a molecule that is the basic building block of the

  nucleic acids DNA and RNA.
• DNA Replication - to produce two identical copies of a DNA molecule.
• Centriole - small cylindrical structure in the cytoplasm in most eukaryotes, but absent in plants & fungi.
• Cell Cycle - an orderly set of events that culminates in the production of new cells.
• Synthesis Phase (S Phase) - DNA doubles through the process of replication. at the end of this stage, each chromosome is made up of two sister chromatids attached at the centromere.
• Telophase - chromatids (now called chromosomes) are located on the opposite poles. The nuclear membrane forms around the chromosomes which start to uncoil.
• Growth1 Phase - at this stage the cell is still young and undergoes rapid growth
• Growth1 Phase (G 1 Phase) - longest phase in most cells.
• Growth1 Phase (G 1 Phase) - cells that are not dividing like muscle & nerve cells, remain at this stage throughout their life cycle.
• Growth 2 Phase (G2 Phase) - a period of rapid cell growth and protein synthesis during which the cell prepares itself for mitosis.
• Growth 2 Phase (G2 Phase) - assembly of proteins, like microtubules, which are hollow protein fibers that cause the chromosomes to move during cell division occur.
• M (Mitosis/Meiosis) Phase

  • cell undergoes division:
  • division of the nucleus is called karyokinesis
  • division of cytoplasm is called cytokinesis
• Karyokinesis - division of nucleus.
• Cytokinesis - division of cytoplasm.
• Mitosis - is a type of cell division in which the nucleus of the cell divides into two nuclei with identical genetic material.
• Paternal & Maternal - two sets of chromosomes.
• Prophase - begins at prophase with the thickening and coiling of the chromosomes.
• Metaphase - during this stage, chromosomes move and align themselves at the center of the cell called metaphase plate.
• Anaphase - at this stage, the proteins that bind the two sister chromatids of each chromosome divide.
• Telophase - chromatids (now called chromosomes) are located on the opposite poles. The nuclear membrane forms around the chromosomes which start to uncoil.
• Cytokinesis - in plant cells, this starts at the middle of the cell and moves outward, and it’s called cell plate formation.
• Cell cycle checkpoints - group of proteins that check the condition of the cells if they’re capable of proceeding to the division of the cell.
• G1 checkpoint - ensures that the cell is ready to undergo DNA synthesis or S phase
• G2 checkpoint - makes sure that the cell is mature enough to divide or undergo M phase
• M checkpoint - occurs during metaphase stage of cell division, sees to it that the cell is ready to complete cell division.
• Apoptosis - programmed celldeath
• Apoptosis - is a suicide of cell's where the cell destroys itself maintaining the smooth functioning of the body
• Necrosis - death of body tissue.
• If checkpoints are not fully functioning, it may

  result in unregulated cell division, which might

  lead to cancer.
• Cyclin Dependent Kinase - a group of proteins that control the progression of the cell cycle by activating particular enzymes
• Tumor protein ( p53 ) - a protein that blocks the cycle if the DNA is damaged
• Cancer - occurs when cells undergo mutation, resulting in their inability to control their normal growth mechanisms and leading to an unregulated cell division.