Biology paper one

• 1 order of magnitude means 10x greater than one before
• animal cells are eukaryotic cells

  nucleus-stores genetic material

  cell membrane-controls what enters and leaves the cell

  cytoplasm-watery solution where chemical reactions take place

  mitochondria-where aerobic respiration takes place

  ribosomes-site of protein synthesis

  plant cells contain chloroplasts which have a pigment called chlorophyll absorbing sunlight for the process photosynthesis

  vacuole which has cell sap , helps with shape
• sperm cells adaptations for fertilisation

  -long tail to swim to the egg

  mitochoindria-release energy

  enzymes;digest their way through outer layer of ovum
• Root hair cells increase the surface area so water and mineral ions can be absorbed.
• Root hair cells do not contain chloroplasts as they are underground and do not go through photosynthesis.
• Xylem forms long hallow tubes which means water and minerals can easily flow through.
• Xylem is found in the stem.
• Xylem carries water and dissolved minerals from the root to the leaf.
• Phloem carries dissolved sugars up and down the plant.
• Phloem vessel cells have no nucleus and limited cytoplasm.
• End walls of phloem vessel cells have pores called sieve plates which allow dissolved sugars to move.
• Companion cells are connected by pores which have mitochondria to provide energy to the phloem vessel.
• nerve cells-send electrical impulses its adaptations are ;

  Axon-carries electrical impulses

  myein-insulates axon and speeds up transmissiOn
• muscle cells contract they contain protein fibres which can change the length

  work to form tissues

  packed full of mitochondria for energy
• What do dendrils do ?

  Increase the surface area
• what is the role of the synpase

  Allow impulse to pass through one nerve to another
• Animals and plants are both eukaryotic cells

  eukaryotic cells contain genetic material (dna) enclosed in a nucleus

  bacteria are prokaryotic cells

  the genetic material is not enclosed in a nucleus and are significantly smaller than eukaryotic cells
• "Centi" means 1/100th of a metre

  Icm=1x101-2,

  1cm=10mm

  "milli" means 1/1000th of a metre

  1mm=-1x10^-3

  micrometre means 1/1000000th

  1 micrometre = 1 x10^-

  "nano" means 1/1 000 000 000th

  Inm=1x10^-9