cell structure

• the two types of cells are prokaryotic and eukaryotic cells
• prokaryotic cells are much smaller than eukaryotic cells. eukaryotic cells membrane bound organelles, and a nucleus containing genetic material.
• eukaryotic cells are plant and animal cells, but prokaryotic cells are bacteria cells.
• genetic information stored in prokaryotic cells is with chromosomal DNA(a large loop of DNA) and plasmid DNA
• plasmids carry genes such as providing genetic resistance to antibiotics
• 5 components of both animal and plant cells: ribosomes, mitochondria, nucleus, cytoplasm, cell membrane
• organelles only found in plant cells are: chloroplants, permanent vacuole, and the cell wall.
• what is the function of the nucleus?

  controls cellular activities
• what is the function of a cytoplasm?


  site of cellular reactions such as respiration
• what is the function of the cell membrane?


  controls what comes in and out of the cell
• what is the function of the mitochondria?


  produces ATP energy using glucose and oxygen
• what is the function of the ribosomes?


  protein synthesis
• the cell wall is made of cellulose
• what is the function of the cell wall?


  keeps the structure of the cell, as well as prevents the cell from bursting when water enters by osmosis
• the permanent vacuole contains cell sap, and it supports the cell
• what is the function of chloroplasts?


  photosynthesis
• how is a sperm cell adapted to its function?

  • tail enables movement
  • mitochondria provides energy for movement
  • nucleus contains genetic information
• how are nerve cells adapted to their function?

  • long axon allows electrical impulses to be transmitted
  • myelin sheath insulates axon speeding up transmission of impulse
  • dendrites connect to nerve cells which receive impulses from other nerve cells
• how are muscle cells adapted to their function?

  • mitochondria to provide energy for muscle contraction
  • protein filaments allowing them to slide over eachother producing muscle contraction
• how are root hair cells adapted to their function?

  • large surface area allowing water and nutrients to be absorbed
  • thin walls to not restrict water absorption
• how are xylem cells adapted to their function?

  • thick cell wells for strength
  • hollow tube providing a continuous route for water to flow
• how are phloem cells adapted to their function?

  • companion cells provide energy needed for active transport
  • sieve plates let dissolved sugars and amino acids travel up and down the strem
• cell differentiation is when a cell becomes specialized
• what is the purpose of cell division ?

  for growth and repair
• the advantages of light microscopes are:

  • inexpensive
  • easy to use
  • portable
  • observe both dead and living speciman
• disadvantages of light microscopes are limited resolution
• advantages of electron microscopes are:

  • greater magnification
  • greater resolution
• electron microscopes allow for each sub-cellular structure to be seen
• disadvantages of electron microscopes are:

  • expensive
  • not portable (because they are big)
  • only dead specimen can be observed
• magnification = size of image $\div$ size of real object