Biology Cell biology Topic 1

• What are the two types of cells that all living things are made of?

  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 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 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
• What is the role of cytoplasm in a cell?

  Site of chemical reactions
• What is the function of the cell membrane?

  Controls what enters and leaves the cell
• Where do aerobic respiration reactions occur in a cell?

  In the mitochondria
• What is the function of ribosomes?

  Where protein synthesis occurs
• What is the role of chloroplasts in plant cells?

  Where photosynthesis takes place
• What is the function of the permanent vacuole in plant cells?

  Contains cell sap and improves rigidity
• What is the composition of the cell wall in plant cells?

  Made from cellulose
• What is the main difference between bacterial cells and eukaryotic cells?

  Bacterial cells lack a nucleus
• How do bacteria multiply?

  By binary fission
• What is the formula to calculate the number of bacteria after divisions?

  Bacteria at beginning x 2$^{\text{number of divisions}}$
• What is the mean division time for bacteria?

  The time taken for one division
• What is the purpose of soaking paper discs in antibiotics during an experiment?

  To test their effect on bacterial growth
• What does the size of the clear area around antibiotic discs indicate?

  Effectiveness of the antibiotic
• Why must inoculating loops be sterilized?

  To kill unwanted microorganisms
• Why should the Petri dish be sealed but not completely?

  To prevent contamination while allowing oxygen
• Why should the Petri dish be stored upside down?

  To prevent condensation disrupting growth
• At what temperature should cultures be incubated?

  25 degrees Celsius
• Why is it risky to incubate bacteria at 37 degrees Celsius?

  It allows harmful bacteria to grow
• What is standard form used for in microscopy?

  To handle large or small numbers
• What is the formula for calculating the size of an object?

  Size of image / magnification
• Who first observed cells and when?

  Robert Hooke in 1665
• What is the maximum magnification of a light microscope?

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

  200 nm
• What are the two types of electron microscopes?

  Scanning and transmission electron microscopes
• What is the main advantage of electron microscopes over light microscopes?

  Higher magnification and resolving power
• What is the formula for calculating magnification of a light microscope?

  Eyepiece lens x objective lens
• What is the function of muscle cells?

  To contract quickly for movement
• What is the role of root hair cells?

  To absorb water and minerals from soil
• What is the function of xylem cells?

  To transport water and minerals up the plant