Topic 2- BIO

• What are the distinguishing features of eukaryotic cells?

  Cytoplasm with membrane-bound organelles
• Why is DNA enclosed in a nucleus in eukaryotic cells?

  To protect genetic information from damage
• What is the general structure of eukaryotic cells?

  • Algal and fungal cells are similar to plant cells
  • Contains membrane-bound organelles
  • Enclosed DNA in a nucleus
• What is the function of the cell-surface membrane?

  Selectively permeable for substance control
• How do molecules on the cell-surface membrane assist the cell?

  They allow cell recognition and signaling
• What is the structure of the nucleus?

  Contains genetic information and nucleolus
• What is the function of the nucleus?

  Stores genetic information coding for proteins
• What occurs at the nucleolus?

  Ribosomes and rRNA are produced
• What is the structure of a ribosome?

  Made of ribosomal RNA and protein
• What is the function of a ribosome?

  Site of protein synthesis (translation)
• What is the structure of rough endoplasmic reticulum (rER)?

  Has ribosomes on its surface
• What is the function of rough endoplasmic reticulum (rER)?

  Synthesizes and processes proteins
• What is the function of smooth endoplasmic reticulum (sER)?

  Synthesizes and processes lipids
• What does the Golgi apparatus do?

  Modifies proteins and packages them
• What is the structure of Golgi vesicles?

  Transport proteins and lipids
• What is the function of lysosomes?

  Release enzymes to break down pathogens
• What is the structure of mitochondria?

  Site of aerobic respiration
• What is the function of mitochondria?

  Produces ATP for energy release
• What is the structure of chloroplasts?

  Absorbs light energy for photosynthesis
• What is the function of chloroplasts?

  Produces organic substances like carbohydrates
• What is the structure of the cell wall in plants?

  Composed mainly of cellulose
• What is the function of the cell wall in plants?

  Provides mechanical strength to the cell
• What is the structure of the cell vacuole in plants?

  Maintains turgor pressure in the cell
• What is the function of the cell vacuole in plants?

  Stores sugars, amino acids, and waste chemicals
• How are eukaryotic cells organized in multicellular organisms?

  • Eukaryotic cells become specialized for functions
  • Form tissues, organs, and organ systems
• How can you explain adaptations of eukaryotic cells using organelles?

  • [Named cell] has many [named organelle]
  • To [link organelle function to cell function]
• What are the distinguishing features of prokaryotic cells?

  Cytoplasm lacking membrane-bound organelles
• Compare the structure of eukaryotic and prokaryotic cells.

  Eukaryotic cells:

  • Have membrane-bound organelles
  • Have a nucleus with DNA
  • Larger ribosomes (80S)

  
  

  Prokaryotic cells:

  • No membrane-bound organelles
  • DNA is free in cytoplasm
  • Smaller ribosomes (70S)
• Why are viruses described as acellular and non-living?

  Not made of cells and lack metabolism
• What is the general structure of a virus particle?

  Nucleic acids surrounded by a capsid
• What do attachment proteins on viruses do?

  Allow attachment to specific host cells
• What are the principles and limitations of optical microscopes?

  Principles:

  • Light focused using glass lenses
  • Can view living organisms

  
  

  Limitations:

  • Low resolution
  • Cannot see internal structures
• What are the principles and limitations of transmission electron microscopes (TEM)?

  Principles:

  • Electrons focused using electromagnets
  • Generates a 2D image of a cross-section

  
  

  Limitations:

  • Can only view dead specimens
  • Very complex preparation
• What are the principles and limitations of scanning electron microscopes (SEM)?

  Principles:

  • Electrons deflected off specimen surface
  • Generates a 3D image of surface

  
  

  Limitations:

  • Can only view dead specimens
  • Very complex preparation
• What is the formula for magnification?

  Magnification = size of image / size of real object
• What is the difference between magnification and resolution?

  Magnification is image size ratio; resolution is detail
• What are the steps in calculations involving magnification?

  1. Note formula (I = AM)
  2. Convert units if necessary
  3. Calculate answer and check units
• How do you convert between different units?

  • Centimetre (cm): 1/100 m
  • Millimetre (mm): 1/1000 m
  • Micrometre (µm): 1/1000000 m
  • Nanometre (nm): 1/1000000000 m
• How can the size of an object viewed with an optical microscope be measured?

  1. Line up eyepiece graticule with stage micrometre
  2. Calibrate eyepiece graticule
  3. Measure object size using graticule
  4. Calculate size of object
  5. Recalibrate at different magnifications
• What are the principles of cell fractionation and ultracentrifugation?

  1. Homogenise tissue to release organelles
  2. Use cold, isotonic, buffered solution
  3. Filter homogenate to remove debris
  4. Ultracentrifugation separates organelles by density