My notes

• BIOLOGY, THE STUDY OF LIFE
• WOLDBY !
• MODULE 1: BIOLOGY, THE STUDY OF LIFE
• Unifying Themes in Biology

  • Chemical Bonds
  • Biology
  • Chemical Basis of Life
  • Macromolecules
  • Vitamins
  • Water
• Characteristics of life (Unifying Themes in Biology)

  • Response to Environment
  • Metabolism
  • Reproduction
  • Homeostasis
  • Organization
  • Evolution
  • Genetic material
• Response to Environment


  Living organisms detect changes in the environment called stimulus and respond to them
• Stimulus


  Anything that can be detected and can bring about a response
• Types of Tropism


  • Geotropism (response to gravity)
  • Phototropism (response to light)
  • Thigmotropism (response to touch)
• Tropism is movement or growth in response to an environmental stimulus, dependent on direction
• Positive Tropism is movement toward a stimulus
• what is going on it's medicosa's perfect status where medicine makes perfect sense this is the ultimate biology review video
• first of all let me be clear trying to review all of biology in less than 90 minutes is an insane task
• I'm going to go over the most important points in this video and we'll do this in the following order
• Topics covered


  • Cell and what's in it
  • Reproduction - mitosis and meiosis
  • Embryogenesis and fetal circulation
  • Nervous system - somatic and autonomic, central and peripheral
  • Endocrine system
  • Respiratory system
  • Cardiovascular system
  • Immune system
  • Digestive system
  • Homeostasis - kidney and skin
  • Musculoskeletal system - bone and muscle
  • Genetics and evolution
• Cell theory


  1. All living things are composed of cells
  2. Cells are the basic functional unit of life
  3. Cells arise only from pre-existing cells
  4. Cells carry genetic information in the form of DNA
• Prokaryotes


  Cells without a true nucleus, DNA is not protein-bound and is circular
• Eukaryotes


  Cells with a true nucleus bound by a membrane, organelles also bound by membranes, DNA is linear and protein-bound
• Examples of eukaryotes


  • Mammals, including humans
• Cell


  • Has a nucleus, cytoplasm, and is surrounded by a plasma membrane

  Genetic material is DNA organized into chromosomes in the nucleus

  Contains organelles like mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus
• Plasma membrane


  Phospholipid bilayer, with hydrophilic heads facing outwards and hydrophobic tails facing inwards
• Cytoplasm


  Fluid containing organelles, but not the nucleus
• Cytosol


  Fluid with no organelles
• Protoplasm


  Nucleus and cytoplasm together
• Nucleus


  • Contains DNA, organized into chromosomes

  Surrounded by a nuclear membrane with pores

  Continuous with rough endoplasmic reticulum
• DNA replication


  Making a copy of DNA
• Transcription


  Converting DNA into RNA
• Translation


  Converting RNA into proteins
• Mitochondria


  • The powerhouse, provides energy in the form of ATP

  Has its own DNA, inherited only from the mother

  Contains enzymes for the electron transport chain and Krebs cycle
• Lysosome


  Contains hydrolytic enzymes to break down foreign material and old cell components
• Endoplasmic reticulum


  • Rough ER - site of protein synthesis

  Smooth ER - site of lipid synthesis and detoxification
• Golgi apparatus


  • Modifies, sorts and packages cellular products for delivery
• Peroxisome


  Breaks down fats and hydrogen peroxide
• Cytoskeleton


  • Network of protein filaments that provide structure and allow movement

  Includes microfilaments, microtubules, and intermediate filaments
• Cilia and flagella


  Extensions of the cell with a specific arrangement of microtubules to allow movement
• Types of tissues


  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Epithelial tissue


  • Covers surfaces and lines cavities

  Supported by a basement membrane
• Connective tissue


  • Provides support, framework and structure

  Includes bone, cartilage, fat, blood, lymph
• Cell cycle


  G0 (resting), G1 (growth), S (DNA replication), G2 (growth), M (mitosis or meiosis)
• Mitosis


  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase
• Karyokinesis (nuclear division) and cytokinesis (cell division) occur during the M phase of the cell cycle