bio paper 2 ans

• whats the balanced symbol equation for photosynthesis

  6h2o+6co2--> c6h12o6+6o2
• what type of reaction is photsynthesis

  endothermic reaction
• what are the limiting factors of photosynthesis

  concentration of carbon dioxide, light intensisty, wind
• name 3 structures of a leaf

  the stoma, guard cells, phloem, xylem, cuticle
• whats the role of the xylem and phloem

  the xylem carries water and minerals upwards and the phloem carries food downwards
• what’s the xylem and its functions

  hallow tubes that carry water and dissolved mineral ions upwards. Transpiration happens there. The rate is increased with air movement or temperature and is decreased by humidi
• what’s the roots

  Water enters there through osmosis, and mineral ions by active transport: root hair cells have large surface area so rate of exchange is maximized
• Where does photosynthesis happen in

  The leaf
• What’s the phloem and its functions

  Tubes of living cells that carry sugars: translocation happens there
• Describe the practical of photosynthesis 


  Cut down pondweed stem, put in inverted measuring cylinder filled with water add co2 measure the distance from light source. Then measure the volume of oxygen or count the bubbles. repeat at different distances
• What’s homeostasis 


  An organisms ability to regulate its internal conditions so crucial reactions can happen at optimal rates
• What needs to be regulated?

  Blood glucose concentration, internal temperature and water levels
• What’s the endocrine system 


  System of glands to secrete hormones to send signals to effectors transported via blood
• What’s the pituitary gland


  It’s the master gland it sends signals to ther glands
• What’s the pancreas purpose

  To produce insulin to control blood sugar
• what’s the thyroids purpose

  to produce thyroxin, it controls growth and metabolisms
• What’s the adrenal gland’s purpose

  Releases adrenaline which is important for flight or fight response
• What’s the ovaries purpose

  Releases eggs and secrete hormones
• what’s the testes purpose

  Produces sperm
• what does the pancreas do if the blood glucose levels are high

  pancreas produces insulin which causes glucose to move from the bloodstream into cells to be used for respiration. Excess glucose is converted into glycogen as energy stores
• What does the Pancreas do if blood sugar levels are to low

  Pancreas releases glucagon which causes the liver and muscles to convert glycogen back into glucose (negative feedback)
• what type 1 diabetes

  Pancreas cannot produce (enough) insulin, injections are needed
• What’s type 2

  Cells do not absorb glucose as they should anymore. Caused by obesity
• What happens if your thyroxine is too low


  The hypothalamus in the brain releases TRH which causes pituitary gland to release TSH which causes the thyroid to produce more thyroxine
• Describe the menstrual cycle

  FSH causes The egg to mature and the ovaries produce oestrogen which causes the uterus lining to thicken and it inhibits FSH so no more eggs mature. Then LH is produced causing egg to be release, which travels towards the uterus a sperm can fertilse it. Progesterone is then made by the ovaries which maintains the uter lining
• give two non barrel contraceptives

  FSH pills stops eggs from maturing and progesterone injection or implants stops eggs from being released
• give two barriers contraceptive

  Condom and diaphragm stops sperm from entering the vagina
• How does the iud work

  Stops egg from embedding in lining
• Describe IVF

  Eggs are collected after inducing release with LH to be fertilized in a lab, viable embryos inserted back into woman’s uterus. success rate is very low and it can potentially cause multiple embryos to develo.
• Describe the process of the heart

  Double circulatory system. Blood enters twice. Blood enters through the vena cava into the right atrium the right ventricle stops backflow from happening. The deoxygenated blood goes through the pulmonary artery to the lungs to be oxygenated. It then goes back through pulmonary vein into left atrium then into left ventricle and out to the body through the aorta
• Why does the left side have thicker walls

  Due to higher pressure needed to pump blood to the body
• What direction does veins travel blood through

  In
• What direction does arteries take blood

  Out
• describe The artery

  Thick walls and thin Luman To withstand high pressure
• Describe the veins

  Thin walls and wide lumen, valves to prevent backflow
• What’s capillaries

  One cell thick walls to allow fast diffusion between blood and cells
• Describe the respirstory system

  Air moves down the trachea, into the bronchi and then bronchioles and ends up in the alveoli the oxygen diffuses into the blood stream and binds to the haemoglobin in red blood cells to be transported
• Explain one adaptment of alveoli

  Have large surface area to allow gas exchange to occur at a fast rate
• What’s the equation for aerobic respiration

  Glucose + oxygen-> water + carbon dioxide

  c6h12o6 + 6o2-> 6h2o + 6co2
• What’s anaerobic respiration

  It’s respiration without oxygen. Occurs during intense exercise: oxygen debt lactic acid is broken back down into glucose by the liver using oxygen