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• effector 


  muscle or gland that brings out a response
• levels of organisation within an ecosystem

  producer-plants and algae which photosynthesise primary consume-herbivores which eat producers secondary consumers-carnivores which eat primary consumers tertiary consumers-also carnivores they eat secondary consumers
• synapse 


  gap between two neurones
• homeostasis


  the maintenance of a constant internal environment
• eukaryotes

  Cells that have a nucleus and membrane-bound organelles
• active transport 


  used in the gut when there is a lower concentration of nutrients in the gut but a higher concentration of nutrients in the blood
• osmosis 


  osmosis is the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
• chloroplasts 


  where photosynthesis occurs which makes food for the plant they contain chlorophyll which absorbs the light needed for photosynthesis
• rigid cell wall

  made of cellulose it supports and strengthens the cell
• permanent vacuole

  contains cell sap a weak solution of sugar and salts
• nucleus

  contains genetic material that controls the activities of the cell
• mitochondria 


  these are where most of the reactions for aerobic respiration take place, respiration transfers energy that the cell needs to work
• ribosomes

  these are where proteins are made in the cell
• cell membrane

  holds the cell together and controls what goes in and out
• cytoplasm

  gel like substance where most of the chemical reactions happen it contains enzymes
• differentation

  the process by which a cell changes to become specialised for its job
• sperm cells

  -the function is to get male dna to the female dna

  -it has a long tail and a streamlined head to help it swim to the egg

  -there are lots of mitochondria in the cell to provide the energy needed

  -it also carries enzymes in the head to digest through the egg membrane
• nerve cells 


  -the function is to carry out electrical signals from one part of the body to another

  -these cells are long and have branched connections at their ends to connect other nerve cells and form a network throughout the body
• muscle cells

  -the function of a muscle cell is to contract quickly

  -These cells are long and contain lots of mitochondria to generate the energy needed for contraction
• root hair cells 


  -root hair cells or cells on the surface of plant roots which grow into long hair that stick out into the soil

  -This gives the plan a big surface area for absorbing water and mineral irons from the soil
• xylem and phloem

  -phloem and xylem cells form phloem and xylem tubes which transport substances such as food and water around plants

  -To form the tubes cells are long and joined and join end to end

  -xylem cells are hollow in the centre and phloem cells have very few sub cellular structures so that stuff can flow through them
• diffusion

  Diffusion is the spreading out of particles from an area of higher concentration to an area of lower concentration
• Single celled organisms

  In single celled organisms, gases and dissolved substances can diffuse directly into or out of the cell across the cell membrane because they have a large surface area compared to the volume
• lungs

  The job of the lungs is to transfer oxygen to the blood and to remove waste carbon dioxide from it to do this as lungs contain millions of the little air sack called alveoli where gas exchange takes place
• how the alveoli are specialised

  -They have an enormous surface area

  -A moist lining for dissolving gases

  -Very thin walls

  -A good blood supply
• catalyst

  A catalyst is a substance which increases the speed of a reaction without being changed or used up in the reaction
• active site

  every enzyme has an active site with a unique shape that fits onto the substance involved in a reaction(lock and key)
• pancreas

  Produces protease,amylase and lipase enzymes it releases these into the small intestine
• liver

  Where bile is produced bio neutralises stomach acid and they emulsifies fats
• large Intestine

  Where excess water is absorbed from the food
• stomach

  produces hydrochloric acid to kill bacteria and to give the right pH for the protease enzyme to work
• small intestine

  produces protease and amylase and lipase enzymes to complete digestion

  this is also where the digestive food is absorbed out of the digestive system into the blood
• alveoli


  Carry out gas exchange in the body
• right ventricle(heart)

  pumps deoxygenated blood to the lungs to take in oxygen which then returns to the heart
• left ventricle

  pumps oxygenated blood around all the other organs of the body the blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart heart pumped to the lungs again
• arteries


  Carry blood away from the heart
• capillaries


  These are involved in the exchange of materials at the tissues
• veins


  These carry blood to the heart
• red blood cells

  carry oxygen from the lungs to all cells in the body

  contain pigment called haemoglobin
• White blood cells

  -Defend against infection

  -Some chain shaped to engulf unwelcome microorganisms

  -Some produce antibodies to fight microorganisms

  -They have a nucleus