Biology topic 1

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

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

  Eukaryotic cells
• What organelles are found in eukaryotic cells?

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

  Prokaryotic cells
• What organelles do bacterial cells have?

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

  Structures in a cell with different functions
• How do we understand the size difference between objects?

  Using orders of magnitude
• What does it mean if an object is 10 times bigger than another?

  It is 10$^1$ times bigger
• What is the prefix for multiplying a unit by 0.01?

  Centi
• What are the prefixes for common metric units?

  • 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 and food production for plants
• What is the role of the permanent vacuole?

  • Contains cell sap and improves 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 roles
• What are stem cells?

  • Cells that can differentiate throughout life
• What is the function of sperm cells?

  • Carry male DNA to the egg cell
• How are nerve cells specialized?

  • Transmit electrical signals quickly
• What is the role of muscle cells?

  • Contract to move bones or squeeze
• What is the function of root hair cells?

  • Take up water and minerals from soil
• What do xylem cells do?

  • Transport water and minerals up the plant
• What is the role of phloem cells?

  • Carry products of photosynthesis throughout the plant
• What is the process of differentiation in stem cells?

  • Genes are switched on or off
  • Produce different proteins for specific functions
• What happens to most animal cells after differentiation?

  • They lose the ability to differentiate
• How do plant cells differ in differentiation compared to animal cells?

  • Many retain ability to differentiate throughout life
• Who first observed cells and when?

  Robert Hooke in 1665
• 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 creates 3D images
  • TEM creates 2D images
• What is the maximum magnification of an electron microscope?

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

  0.2nm
• What is the formula for magnification of a light microscope?

  Magnification = eyepiece lens x objective lens
• How do you calculate the size of an object using a microscope?

  Size of object = size of image / magnification