CELL CYCLE & CELL DIVISION (FINAL)

• Any sexually reproducing multicellular organism begins as a single-celled entity.
• The single-celled entity then relies on cellular events to produce more cells, the early stage of which is shown in the blastula.
• Further growth and development proceed through the continuous reproduction and specialization of cells. The process repeats for as long as needed to ensure the maintenance and survival of an individual.
• DNA Molecule: Almost every cell in our bodies has genetic material in the form of deoxyribonucleic acid (DNA).
• Most biological traits such as eye color, hair color, and height are coded for by the DNA.
• DNA, the primary genetic material of living organisms, stores genetic information in the sequences of its nucleotides.
• Positively charged histone proteins aid in DNA packaging.
• Interphase DNA is found in the form of chromatin, a complex of DNA and proteins.
• Chromatin in dispersed inside the intact cell nucleus during interphase.
• Chromatin will sometimes need to further condense into a highly coiled and compact structure. This highly condensed form of DNA is known as a chromosome.
• Chromatin condenses into chromosomes. Each half of the chromosome is a chromatid.
• The life cycle of a cell is known as the cell cycle, and this describes how cells grow, develop, and reproduce.
• Interphase (Gap 1): Growth of cytoplasm and doubling of organelles; Produce proteins, enzymes, nutrients, and energy; Highest rate of protein synthesis; Movement of centrioles of the centrosomes away to await and assist the events of mitosis.
• Interphase (S): This stage is named so because it is when the cell synthesizes a copy of its DNA in a very notable process called DNA replication. This refers to the event when an existing DNA produces another copy of itself.
• Interphase (Gap 2): Continued growth and the production of materials that are necessary for cell division to occur; Protein synthesis but not at the rate similar to that of the G1 phase.
• M Phase (Mitosis or Meiosis): The M phase in eukaryotic organisms involves either one of two processes, namely, mitosis and meiosis.

  Sex cells or gametes undergo meiosis, whereas somatic cells or non-sex cells undergo mitosis.
• Cytokinesis is marked by the formation of a cleavage furrow in animal cells.
• Cytokinesis is marked by the formation of a cell plate in plant cells.
• G1 to S Checkpoint: Is there any damage in the cell’s DNA?; Is the cell large enough with all the necessary energy reserves and doubled organelles?
• G2 to M Checkpoint: Are the environmental conditions favorable for cell division to take place?; Is the DNA properly replicated?; Is there a presence of DNA damage?
• M Checkpoint: Are the spindles properly attached?
• All of the cells in your body contain genetic material in the form of DNA or deoxyribonucleic acid, which is usually found in the nucleus of your cells.
• There are three main stages in the cell cycle, namely, interphase, M phase, and cytokinesis.