topic 1- cell biology

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

  Prokaryotic and eukaryotic
• What are the main components of eukaryotic cells?

  • Cell membrane
  • Cytoplasm
  • Nucleus containing DNA
• What are the components of prokaryotic bacterial cells?

  Cell wall, cell membrane, cytoplasm, single circular strand of DNA, and plasmids
• What is the function of organelles in a cell?

  They are structures that have different functions within the cell
• How do we express the size difference between objects using orders of magnitude?

  If an object is 10 times bigger, it is 10$^1$ times bigger
• What do prefixes indicate in measurements?

  They show the multiple of the unit
• What are the prefixes used in measurements and their corresponding values?

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

  It contains DNA coding for proteins needed to build new cells
• What is the function of cytoplasm in a cell?

  It is the liquid substance where chemical reactions occur
• What is the function of mitochondria in a cell?

  They are where aerobic respiration occurs, providing energy
• Where does protein synthesis occur in a cell?

  In ribosomes
• What is the role of chloroplasts in plant cells?

  They are where photosynthesis takes place
• What is the function of a permanent vacuole in plant cells?

  It contains cell sap and improves the cell's rigidity
• What is the composition of the cell wall in plant cells?

  It is made from cellulose
• How do bacterial cells differ from eukaryotic cells in terms of organelles?

  Bacterial cells do not share as many similarities in organelles as animal and plant cells
• What is cell specialization and differentiation?

  • Cells specialize by undergoing differentiation
  • This involves gaining new sub-cellular structures
  • Allows cells to be suited to their specific roles
• What is the main function of sperm cells?

  To carry the male's DNA to the egg cell for reproduction
• How are nerve cells specialized for their function?

  They transmit electrical signals quickly from one place to another
• What is the function of muscle cells?

  To contract quickly to move bones or squeeze
• What is the role of root hair cells in plants?

  They take up water and mineral ions from the soil
• How do xylem cells function in plants?

  They transport water and mineral ions from the roots to the shoots
• What is the function of phloem cells in plants?

  They carry the products of photosynthesis to all parts of the plant
• What is the process of differentiation in stem cells?

  It involves switching genes on or off to produce different proteins
• How many chromosomes are there in each human cell?

  46 chromosomes in total
• What is the exception regarding the number of chromosomes in sex cells?

  They have half the number of chromosomes, resulting in 23 chromosomes
• What is the cell cycle?

  It is a series of steps that the cell undergoes to divide
• What is the first stage of the cell cycle?

  Interphase
• What happens during interphase?

  The cell grows and organelles are duplicated
• Who first observed cells in cork 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 is the main advantage of an electron microscope over a light microscope?

  It allows viewing of deep inside sub-cellular structures
• What are the two types of electron microscopes?

  Scanning electron microscope and transmission electron microscope
• What is the magnification of a scanning electron microscope?

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

  0.2 nm
• What are the common calculations in microscopy?

  1. Magnification of a light microscope: eyepiece lens x objective lens
  2. Size of an object: size of image/magnification = size of object
• What is standard form and why is it useful in microscopy?

  It helps in working with very large or small numbers
• What is the purpose of culturing microorganisms?

  To study them in the lab
• What does the culture medium for microorganisms contain?

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

  1. In nutrient broth solution
  2. On an agar gel plate