topic 1-cells

• What are the two main types of cells?

  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
• What are the prefixes used in measurements 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 substance for chemical reactions
  • 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?

  • Photosynthesis takes place
  • 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?

  Bacterial cells have fewer organelles
• 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 roles
• What are stem cells?


  • Cells that can differentiate throughout life
  • Can form specialized cells
• 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 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 structure 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 maximum magnification of a light microscope?

  • Approximately 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 magnification of electron microscopes?

  • Up to x2,000,000
• What is the resolving power of SEM and TEM?

  • SEM: 10nm
  • TEM: 0.2nm
• What is the formula for magnification of a light microscope?

  • Magnification = eyepiece x objective
• What is the formula for the size of an object?

  • Size of object = size of image / magnification
• What is the culture medium for microorganisms?

  • Contains carbohydrates, minerals, proteins, vitamins
• What are the two ways to grow microorganisms in the lab?

  1. Nutrient broth solution
  2. Agar gel plate
• What is the purpose of sterilizing Petri dishes and culture media?

  • Prevent contamination by unwanted microorganisms
• What is binary fission in bacteria?

  • One bacterium splits into two
• What is the formula for calculating the number of bacteria?

  • Bacteria at end = bacteria at beginning x $2^{\text{number of divisions}}$
• What is the role of antibiotics in bacterial growth testing?

  • Determine effectiveness by measuring inhibition zones
• What is the purpose of soaking paper discs in antibiotics?

  • To test their effect on bacterial growth