cell biology

• What are the two types of cells in living organisms?

  Prokaryotic and eukaryotic
• What type of cells are animal and plant cells?

  Eukaryotic
• What are the main components of eukaryotic cells?

  • Cell membrane
  • Cytoplasm
  • Nucleus containing DNA
• What type of cells are bacterial cells?

  Prokaryotic
• What are the main components of prokaryotic cells?

  • Cell wall
  • Cell membrane
  • Cytoplasm
  • Single circular strand of DNA
  • Plasmids
• What are organelles?

  Structures in a cell with different functions
• How do we express size differences using orders of magnitude?

  By powers of ten
• What does it mean if an object is 10 times bigger?

  It is 10$^1$ times bigger
• What does a prefix indicate in measurements?

  It shows the multiple of the unit
• What are the prefixes for common metric units and their values?

  • Centi: 0.01
  • Milli: 0.001
  • Micro: 0.000001
  • Nano: 0.000000001
• What is the function of the nucleus in a cell?

  • Contains DNA coding for proteins
  • Enclosed in a nuclear membrane
• What is the function of the cytoplasm?

  • Liquid where chemical reactions occur
  • Contains enzymes and organelles
• What is the role of the cell membrane?

  • Controls entry and exit of substances
• What occurs in mitochondria?

  • Aerobic respiration reactions for energy
• Where does protein synthesis occur?

  • In ribosomes on rough endoplasmic reticulum
• What is the function of chloroplasts?

  • Site of photosynthesis
  • Contains chlorophyll for light absorption
• What is the role of the permanent vacuole?

  • Contains cell sap
  • Improves cell rigidity
• What is the function of the cell wall?

  • Provides strength to the cell
  • Made from cellulose
• How do bacterial cells differ from eukaryotic cells?

  They have fewer organelles and no nucleus
• What is cell specialization?

  • Process of cells gaining new structures
  • Suited to specific roles
• What is differentiation in cells?

  • Cells gain new sub-cellular structures
  • Suited to their specific function
• What are stem cells?

  • Cells that can differentiate throughout life
• What are the adaptations of sperm cells?

  • Streamlined head and long tail
  • Many mitochondria for energy
  • Acrosome with digestive enzymes
• What are the adaptations of nerve cells?

  • Long axon for distance
  • Many dendrites for connections
  • Mitochondria for neurotransmitter production
• What are the adaptations of muscle cells?

  • Special proteins for contraction
  • Many mitochondria for energy
  • Store glycogen for respiration
• What are the adaptations of root hair cells?

  • Large surface area for water uptake
  • Large vacuole for water movement
  • Mitochondria for active transport energy
• What are the adaptations of xylem cells?

  • Hollow tubes for water transport
  • Lignin for strength and pressure resistance
• What are the adaptations of phloem cells?

  • Sieve plates for substance movement
  • Companion cells provide energy
• What is the process of differentiation in stem cells?

  • Genes switched on or off
  • Produce different proteins for functions
• How do cell division and differentiation differ in animals and plants?

  • Animals: most cells differentiate early
  • Plants: many cells can differentiate throughout life
• What is the role of microscopes in studying cells?

  • Enlarge images of small structures
• Who first observed cells in cork?

  Robert Hooke
• What are the components of a light microscope?

  • Objective lens
  • Eyepiece lens
  • Illuminated from underneath
• What is the maximum magnification of a light microscope?

  x2000
• What is the resolving power of a light microscope?

  200nm
• What is the difference between scanning and transmission electron microscopes?

  • SEM: 3D images
  • TEM: 2D images
• What is the maximum magnification of an electron microscope?

  x2,000,000
• What is the resolving power of a scanning electron microscope?

  10nm
• What is the resolving power of a transmission electron microscope?

  0.2nm
• What are common calculations in microscopy?

  1. Magnification = eyepiece x objective
  2. Size of object = size of image / magnification