cell biology

• what are animal and plant cells classed as

  Eukaryotes
• What is bacteria cells classed as

  Prokaryotes
• What are cells 


  Cells are the smallest unit of life that can replicate independently
• what two things are animal and plant cells doing when they divide

  growing and replacing dead cells
• What are animal and plant cells not doing when they divide

  They are not making whole new organisms
• What can animal and plant cells divide into

  Animal and plant cells can divide into 2 cells then into 4 cells and so on
• How does bacteria divide

  For bacteria and other cases each individual cell is a whole organism so when they divide they are doing asexual reproduction because every division uses a whole new organism
• are plant and animal cells multicellular or unicellular

  multicellular
• what does multicellular mean

  They contain lots of cells
• What do both animal and plant cells contain

  Cell membrane

  nucleus

  cytoplasm

  mitochondria

  ribosomes
• What extra things do plant cells contain

  Rigid cell wall

  permanent vacuole

  chloroplast
• Cell membrane 


  Controls which substances can pass in and out of the cell
• Nucleus 


  Contains genetic material/DNA
• Cytoplasm


  Where chemical reactions take place
• Mitochondria 


  Provide cells with the energy they need to function
• Ribosomes 


  Site of protein synthesis
• Rigid cell wall


  cellulose-support and structure
• Chloroplast 


  where photosynthesis takes place from a substance called chlorophyll
• Permanent vacuole 


  Contains cell sap which is a mixture of sugars salts and water
• Are bacterial cells multicellular or unicellular

  Unicellular
• what does unicellular mean

  One cell
• What do Bacteria cells contain

  Cell wall

  cytoplasm

  cell membrane

  flagella

  plasmids

  circular strand of DNA
• Flagella


  Propels the bacteria
• Plasmids 


  they are extra genes
• Circular strand of DNA(NUCLEOID)

  genes they need to survive and reproduce
• advantages of light microscopes

  small-easy to use

  relatively cheap
• disadvantages of light microscopes


  •rely on light which has a wave length of 0.2μm(micrometers)

  •resolution is also limited to 0.2μm(micrometers)meaning any details less than 0.2μm WILL APPEAR BLURRY

  •so they are not good enough to study the subcellular structures in cells e.g. mitochondria
• advantages of electron microscopes 


  •use electrons instead of light

  •Electrons have a wave length of 0.1nm(nanometers)so there maximum resolution is 0.1nm(nanometers)-2000x better resolution than the light microscopes

  •CAN USE THEM TO STUDY subcellular structures e.g. mitochondria
• disadvantages for electron microscopes

  big-hard to use(used by scientists in laboratories)

  very expensive
• how to convert from Mm(millimetre) to m(meters)


  divide by 1000-as it’s 1000x bigger
• how to get from mm(millimetre) to μm(micrometers)


  times by 1000-as it is 1000x smaller
• how to get from mm(millimetre) to km(kilometre)


  divide by 1000 to get to m(meters)

  then divide by 1000 again to get to km(kilometres)
• how to get from Mm(millimetres)to nm(nanometers)


  times by 1000 to get to μm(micrometers) then times by 1000 again to get to nm(nanometers)
• how to convert cm(centimetres) to something else


  easiest to multiply it to mm(millimetres)-x10

  then u can multiply it to whatever Or divide it
• what do all multicellular eukaryotic organisms require 


  a continuous supply of new cells which are used for GROWTH, DEVELOPMENT and REPAIR
• what is supplies of new cells particularly true for 


  for young organisms who need to grow in size but also true for older organisms who constantly replace lost cells e.g. skin cells
• what is the cell cycle

  •life cycle of the cell

  •process of which cells are generated

  •FROM THE TIME IT WAS MADE FROM THE TIME IT DIVIDES IN TWO NEW CELLS
• what happens to the DNA when a cell is not dividing 


  the DNA is spread out into long strings
• What happens to the DNA when it starts to prepare for division


  •It’s DNA condenses into chromosomes which are coiled up packets of DNA
• What does the DNA of each chromosome contain

  •a large number of genes which control the development of different characteristics e.g. eye colour