Bio Exam Review

• Cell Division happens for 3 reasons

  • Reproduction
  • Growth
  • Repair
• Asexual reproduction


  One parent, offspring are exact genetic copies
• Sexual reproduction


  Fusion of two cells containing half the genetic information from each parent
• DNA (Deoxyribonucleic acid)


  A long chain molecule that contains our unique genetic information
• DNA is made up of 4 building blocks called nucleotides
• Nucleotides


  The 4 building blocks of DNA: Adenine (A), Thymine (T), Guanine (G), Cytosine (C)
• Chromosome


  Tightly packed DNA
• Histone


  Protein molecule that DNA wraps itself around
• Chromatin


  Thin thread of DNA and histones
• Chromatid


  One strand of DNA before replication
• Sister Chromatids


  The product of DNA replication; two identical DNA strands attached by a centromere
• Centromere


  The region where sister chromatids attach
• Homologous Chromosomes


  A pair of chromosomes, one from mom and one from dad, with identical features
• Humans have 46 chromosomes, 23 from mom and 23 from dad, forming 23 homologous pairs
• Replication


  1. Chromatin

  2. Sister Chromatids

  3. Homologous Pairs
• Prokaryotic


  Single celled, no nucleus (bacteria and archaea)
• Eukaryotic


  Cells with a nucleus
• Eukaryotic cells


  • Have organelles
  • Everything
• Cell membrane

  • Flexible membrane
  • Semi-permeable (some things can pass through, others cannot)
• Vesicles


  • Collect and process materials to be removed from the cell
  • Secrete substances
• Mitochondria


  • Where cellular respiration takes place
  • Converts nutrients into energy for the cell to function
  • Active cells have more mitochondria than other cells
• Endoplasmic reticulum


  Network of branching tubes and pockets that transport material throughout the cell
• Proteins


  • Biological molecules made of amino acids
  • Catalyze biological reactions
• Ribosomes


  The proteins that make proteins
• Nucleus


  • Central control center of the cell
  • Contains the genetic information (DNA) of the cell
• Nucleolus


  Produces and assembles ribosomes for the cell
• Chromosomes


  • Structures of DNA in the nucleus of all cells
  • Contains all of the genetic information in the form of genes
• Lysosomes


  Membrane bound organelles that digest biological material