Stuff don’t know

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  $Magnification=$$image size ÷ object(cell) size$
• Eukaryotic cells -

  have a nucleus
• Prokaryotic cells:

  Don’t have a nucleus
• Whats a plasmid?

  A loop of DNA in prokaryotic cells
• What do cell membranes do ?

  • In eukaryotic cells
  • semi permeable
  • controls what enters and leaves
• What are cytoplasm?

  • The liquid wich makes up the cell
  • where most chemical reactions take place
• what are mitochondria?

  • Where respiration takes place
  • releases energy for the cell
• What are ribsomes?

  • where protein synthesis takes place
• What are chloroplasts?

  • Contain chlorophyll
  • where photosynthesis happens
• How many pairs of chromosomes do humans have?

  23
• Steps of mitosis

  1. Nucleus dissolve, genetic material is duplicated
  2. the two sets of chromosomes move to different sides
  3. mitochondria, ribosomes & other organelles are duplicated
  4. the cell divides producing two genetically identical diploid cells
• Diffusion-

  • high concentration-> low concentration
  • down the concentration gradient
  • Does not require energy
• osmosis

  • The movement of water across a semi permeable membrane
  • balances the concentration inside and outside a cell
  • water must move as only it can fit
• Change in mass = (final mass-initial mass) ÷ initial mass
• Active transport-

  • Movement of particles through a membrane
  • requires energy to move them against the concentration gradient
• Cell-> tissue-> organ-> organ system->
• How is food broken down in the stomach?

  contains hydrochloric acid and enzymes that chemically break down food
• The pancreas secretes amylase which breaks down ?

  Starch into glucose in the small intestine
• The liver produces bile wich is stored in the gall bladder before going to the small intestine
• Bile emulsifies lipids to form droplets to increase their surface area