Science Q4

• A cell cycle is a series of events that takes place in a cell as it grows and divides
• Two types of Cells:

  Prokaryotic Cells

  Eukaryotic Cells
• Prokaryotic Cells produce through binary fission
• Eukaryotic Cells follow a cycle of growth and division called as the Cell Cycle
• Mitosis - The process by which one eukaryotic cell divides into two daughter cells.
• Prokaryotic Cells are mostly unicellular organism, that consist of only one cell
• Eukaryotic Cells are multicellular organisms, that consist of multiple number of cells
• Interphase or Growth Phase
• Three Stages:

  First Gap

  Synthesis

  Second Gap
• First Gap is where the Primary Growth of the Cell happens
• Synthesis is where the chromatin and centriole are replicated
• Second Gap is where the cell continues to grow for preparation
• Two Types of Cells:

  Somatic Cells (body cells)

  Sex cells (gametes)
• Sex Cells are Haploid Cells
• Somatic Cells are Diploid Cells
• 23 Chromosome - divided through Meiosis
• 46 chromosomes - divided through Mitosis
• Mitosis - Produce Two Identical Daughter Cells
• Mitosis occurs in 4 phase

  Prophase

  Metaphase

  Anaphase

  Telophase
• Metaphase - is where the chromosomes align at the Metaphase Plate
• Anaphase - the once joined sisters chromatid begins to seperate and move towards the opposite pole of the cell
• Telophase - the nuclear membrane starts to form at the two poles of the cell where the chromosomes have gathered
• Cytokinesis - the cytoplasm of the parents cell physically divides into two
• Meiosis - Type of Cell division that produce Haploid cells
• Mitosis - type of cell division that produce diploid cells
• Zygote - fertilized egg cells that results from the union of a female gamete and make gamete
• Homologous Chromosomes - chromosomes inside the zygote with the same size and shape
• Meiosis involves in two cell division

  Meiosis 1

  Meiosis 2
• In Meiosis, one parent cell produce 4 daughter cells
• In Meiosis, daughter cells are not Identical to the parent cells because of crossing over
• Crossing over - takes place during prophase 1 wherein homologous Chromosomes pair up and exchange genetic materials at their point of contact called Chiasma
• Prophase 1 - they cross over and exchange genetic materials
• Homologous chromosomes pair up in a process called synapsis
• Metaphase 1 - when the spindle fibers are fully formed, the paired homologous chromosomes align at the Metaphase plate
• Anaphase 1 - each pair of the homologous chromosomes separates moving to the opposite poles
• Telophase 1 - the chromosomes moved to opposite poles
• Gene - segment of DNA that controls the expression of traits
• Gregor Johann Mendel - Father of Genetics
• Genes - sequences of nucleotides in DNA that serves as the basic and physical and functional units of heredity
• Heredity - study of passing characteristics or traits through combined genetic materials of the parent