CELLS

• Mitosis


  Cell division process that distributes one copy of the DNA into each of its daughter cells
• Meiosis


  Cell division process that produces haploid gametes (half the number of chromosomes)
• All living things are made of cells
• Why cells are small

  • As cells get bigger, more of the cytoplasm is located farther from the cell membrane
  • If a cell gets too big, it would take too long to get materials into the cell and too long to get waste out of the cell
  • Smaller cells are more efficient
• Cell cycle


  1. Interphase

  2. Cell division or mitotic phase

  
• Interphase


  Interval between two cell divisions where the cell grows, replicates its chromosomes, and prepares for cell division

  
• Stages of interphase


  • G1 (growth phase)
  • S (DNA copying)
  • G2 (preparation)

  
• Sister chromatids


  Copies of a chromosome from mom or dad
• Homologous chromosomes


  One chromosome from mom and one from dad
• Mitosis


  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase
• Cytokinesis


  Division of the cytoplasm resulting in two separate daughter cells with identical nuclei
• Chromosomes are in the nucleus of every cell and are made up of DNA
• Genes are pieces of DNA that contain the instructions for building a protein
• Meiosis


  • Synapsis (homologous chromosomes pair)
  • Crossing over (exchange of genetic material)
  • Reduction division (chromosomes not copied between divisions)
• Meiosis I


  1. Prophase I

  2. Metaphase I

  3. Anaphase I

  4. Telophase I
• Meiosis II


  1. Prophase II

  2. Metaphase II

  3. Anaphase II

  4. Telophase II
• At the end of meiosis, there are 4 haploid cells, each with only 1 copy of each chromosome
• Cells in meiosis get to be different due to crossing over
• Haploid


  Half the number of chromosomes as somatic cells
• If an organism's somatic cells have 36 chromosomes, their gametes have 18 chromosomes
• The nucleus is the control center of the cell.
• Organelles are specialized structures found inside cells, such as mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, centrioles, cilia, flagella, vacuoles, peroxisomes, and chloroplasts (in plant cells).
• The cytoplasm contains organelles that carry out specific functions within the cell.