biology

• Cell theory

  • 1. All cells are made up of one or more cells
  • 2. All cells come from pre-existing cells
  • 3. The cell is the basic unit of structure and organizations
• Unicellular


  Organisms that are made up of only one cell that carries out all the functions
• Unicellular organisms


  • Archaebacteria
  • protists
  • yeast
• Multicellular


  Organisms that are made up of many cells that carry out different functions
• Multicellular organisms


  • Animals
  • plants
  • fungi
• 7 characteristics of life

  • Metabolism
  • Reproduction
  • Homeostasis
  • Growth
  • Response
  • Excretion
  • Nutrition
• Metabolism


  Refers to all the chemical reactions an organism uses to take in and transform energy from the environment
• Metabolism examples


  • Plants convert solar energy into chemical energy via photosynthesis
  • Mammals change the chemical energy stored in plants and other animals into a form of energy called ATP that their cells can use
• Reproduction


  Process in which specific traits are inherited by the offspring
• Types of reproduction


  • Sexual reproduction
  • Asexual reproduction
• Sexual reproduction


  Requires two parents, occurs in animals and plants, and meiosis forms gametes
• Asexual reproduction


  Requires one parents, offspring is genetically identical to parent, mitosis occurs, and occurs in bacteria and some plants
• Homeostasis


  The maintenance of a stable level of internal conditions
• Growth


  Living organisms increase in size and number of cells
• Growth examples


  • Plant getting taller
  • kids getting taller
• Response


  The result of a physical or chemical change in the environment
• Types of stimuli


  • External stimuli
  • Internal stimuli
• External stimuli example


  • Lizards body temperature drops when air cools, so it moves to lay underneath the sun for warmth
• Internal stimuli example


  • Your mouth feels dry when you are dehydrated
• Excretion


  The removal of waste from the body
• Human waste


  • Carbon dioxide
  • salts
  • water
  • urea
  • uric acid
• Plant waste


  • Water
  • carbon dioxide
• Nutrition


  Provides the raw materials for repair and growth
• Types of nutrition


  • Autotrophic
  • Heterotrophic
• Autotrophic


  Makes their own food
• Autotrophic example


  • Plants and photosynthesis
• Heterotrophic


  Eats other organisms
• Heterotrophic example


  • Predators in the food chain
• Differentiation


  When an unspecialized cell becomes a more specialized cell type
• Most cells are specialized
• The first cells to develop in an embryo are stem cells. Stem cells are unspecialized cells that can form different cell types
• Red blood cells


  • They have a flat disc shape which maximizes surface area allowing them to carry more oxygen
  • They contain hemoglobin which carries oxygen molecules
  • They don't have a nucleus which gives them more space to carry oxygen
• Nerve cells


  • They are thin and long so they can carry messages up and down over large distances
  • They have a myelin sheath that surrounds them. The myelin sheath increases the speed at which the messages travel at
  • They connect to other nerve cells at each end of their dendrites allowing them to pass messages throughout the body
• Many types of plant cells retain the ability to differentiate throughout life. These cells found in tissues are called meristems
• In mature animals, cell division is mainly restricted to repair and replacement
• Artificial life


  Life forms or systems created through human engineering, often using synthetic biology techniques
• Artificial life can be extremely beneficial to science, as it can lead to advancements in medicine and create cures to diseases
• Creating artificial life raises ethical concerns about the functional status of artificial organisms and the potential wrongful treatments they might face
• Another ethical concern is the fact that the creation of artificial life might be an act of defiance against God as there are concerns about the moral boundaries of manipulating life in labs
• Photosynthesis


  The process by which plants absorb light from the sun to make their chemical food energy