biology

• chloroplast

  these are where photosynthesis occurs which makes food for the plant
• permeant vacuole

  contains the cell sap, a weak solution of sugar and salt
• cell wall

  made out of cellulose support the cell and strengthens it
• cytoplasm

  gel like- substance  where most of the  chemical  reactions occur
• ribosomes

  these are where proteins are made in the cells
• what are organelles

  Organelles are specialized structures within the cell that have specific functions, such as the mitochondria for energy production.
• nucleus

  The nucleus contains the cell's genetic material (DNA) and controls the cell's activities.
• cell membrane

  The cell membrane holds the cell together and controlls what goes in and out 
• eukaryotic cell


  complex cell with a nucleus found in plant and animal cell
• prokaryotic cell


  simple cell does not have a nucleus found in bacteria cells
• mitochondria

  these are where most of the reactions for aerobic respiration takes place
• what is a cell

  A cell is the basic unit of life for all living organisms.
• Plant cells have a rigid cell wall to support them and chloroplasts to make food by photosynthesis.
• differentiation


  cell changes to become specialised for its job
• what are undifferentiatedcells called?

  stem cells
• how are root hair cells specialised?

  • surface of the plant roots
  • huge surface area
  • able to absorb water and minerals in soil
• how are nerve cells specialised?

  • they carry electrical signals
  • long (cover more distance)
  • branched connections to connect and form a network
• how is a sperm cell specialised?

  • long tail (swim to the egg)
  • streamlined head
  • alot of mitochondria (energy)
  • carry enzymes
• in plants, stem cells are found where?

  meristems( where growth occurs)
• resolution


   resolution is the ability to distinguish two points as separate structures rather a single fuzzy dot
• Diffusion


  the spreading out of particles from an area of high concentration to low concentration until it reaches equilibrium
• what is osmosis


  movement of water molecules from a higher water concentration to a region of lower water concentration across a partially permeable membrane
• what is active transport

  substances absorbed against a concentration gradient form a lower concentration to a higher concentration.
• what is cell dividing called?

  cell cycle
• first stage of mitosis

  DNA replicates to form 2 copies of each chromosome
• second stage of mitosis?

  mitosis takes place pulled to each end of the cell, nucleus also divides
• final stage of mitosis?

  cytoplasm and cell membrane divides creating 2 identical cells
• functions of mitosis

  • sexual reproduction
  • organism repairs itself (Brocken bone healing)
  • growth and development of multicellular organisms (plants and animals)
• step one of mitosis

  dna replicates itself two form 2 copies ofeach chromosone
• mitosis step 2


  mitosis takes place one set of chromosomes is pulled to each end of the cell the nucleus also divides
• step 3 mitosis


  the cytoplasm and the cell membrane divide to form 2 identical daughter cells
• step 1 MEIOSIS


  chromosomes are copied
• meiosis


  only in reproductive cells
• meiosis 


  only takes place in reproductive orgsnas
• stem cells


  cells that can differentiate into different types of specialised cells
• diffusion


  particles from a high-low concentration untill it reaches equillibirum
• osmosis


  movement of particles from high to low concentration through a partially permeable membrane
• active transport


  movement of particles from a low concentration to to a high against a concentration gradient uses atp energy
• test for starch


  add a few drops of iodine to food sample, gently mix, if starch is present colour change from orange to blue/black
• test for sugars

  add a drop of benedict's solution to prepared food sample, gently heat. if positive you will see a colour change from blue to brick-red