Chapter 1: Part 2 & 3

• Alive


  Characteristic of living organisms
• Biological molecules in living organisms

  • Nucleic acids (DNA, RNA)
  • Proteins
  • Carbohydrates
  • Lipids
• DNA encodes genetic information and is made up of 4 nucleotides in a double helix structure
• Cell


  Smallest unit of life
• Types of cells

  • Unicellular (single-celled)
  • Multicellular (many-celled)
• Reproduction

  • Asexual (splitting, cloning)
  • Sexual (combining genetic information from parents)
• Acquire and use energy

  Through processes like photosynthesis and metabolism
• Respond to environment

  Detect stimuli and respond accordingly
• Maintain homeostasis


  Regulate internal environment to stay within optimal range
• Populations of living organisms


  • Evolve and develop adaptive traits for survival
• Viruses are not considered fully alive as they lack some key characteristics of living organisms
• Antibiotic resistance in bacteria is an example of adaptive traits in a population
• Function

  Normal physiological activity of an organ or part
• Produce

  To make something
• Synthesis

  Building up something from building blocks (e.g. synthesizing proteins from amino acids)
• Lack


  Does not contain something
• Inhibit


  Decrease, limit or block the action or function of something
• Stimulate

  Increase the activity, make something work harder
• Dilate

  Make something wider (e.g. blood vessels, pupils)
• Constrict

  Make something smaller (e.g. blood vessels, pupils)
• Levels of organization of life

  • Atom
  • Molecule
  • Organelle
  • Cell
  • Tissue
  • Organ
  • Organ system
  • Organism
  • Population
  • Community
  • Ecosystem
  • Biosphere
• Domains of life

  • Eukarya
  • Bacteria
  • Archaea
• Humans belong in the domain Eukarya, kingdom Animalia, subdivision Vertebrates, group Mammals