Q1

• Which heart vessel brings in deoxygenated blood from the body?

  vena cava
• Which vessel carries deoxygenated blood from heart to lungs?

  pulmonary artery
• Which vessel carries oxygenated blood from lungs to heart?

  Pulmonary vein
• Which vessel pumps oxygenated blood from heart to body?

  aorta
• How is blood pumped to the body?

  Blood enters right atrium and left atrium

  atria contract and blood is forced into ventricles

  ventricles contract and blood is forced out of heart via aorta
• What is the purpose of valves in the heart?


  prevent blood from flowing backwards into the atria when ventricles contract
• Which side of the heart has thicker muscle?

  left
• Why is the left muscle thicker than the right?


  left side pumps blood around the whole body

  right only to lungs
• Why is the left muscle thicker than the right?


  left side pumps blood around the whole bodyleft side pumps blood around the whole body

  right only to lungs
• What are the coronary arteries?


  veins that branch out of aorta and spread out in heart muscle
• What is the purpose of coronary arteries?


  prvise oxygen to muscle cells of the heart
• What is the pacemaker?


  group of cells in right atrium that control beating of heart
• What is the symbol equation for photosynthesis?


  6CO2 + 6H2O → C6H12O6 + 6O2
• Is photosynthesis exothermic or endothermic?


  endothermic- takes in more energy than it releases
• How does increase in temp affect rate of photosynthesis?


  gives enzymes energy until certain temp they denature and rate of reaction decreases.
• How does light intensity affect photosynthesis?


  higher the light intensity the faster the rate if photosynthesis
• how does carbon dioxide conc. affect photosynthesis?


  as co2 increases, rate of reaction increases
• What is a limiting factor?


  an environmental condition which limits rate of photosynthesis in short supply
• What do glucose molecules do as soon as they are made?


  join together to form starch
• Why do plants convert glucose into starch?


  easier to store, converted back into glucose when needed for respiration
• What happens at night?

  starch is converted into sucrose, easier to move around plant
• How can knowledge of limiting factors benefit us?


  farmers can use limiting factors to enhance conditions for greater rate of photosynthesis
• What is transpiration?


  process of water movement against gravity (from roots to leaves)
• Where does transpiration take place?

  xylem
• 3 substances that move in and out of the stomata?


  oxygen

  carbon dioxide

  water vapour
• what is translocation?


  movement of sucrose and amino acids from leaves to other parts of the plant
• Where does translocation take place?


  phloem
• How does transpiration work?


  water travels up through xylem tubes

  water evaporates through stomata in leaves

  as water evaporates it drags another water molecule up to take its place
• what is transpiration stream?


  chain of water molecules
• How does light affect transpiration?


  if light increases stomata will open wider to allow more co2 into leaf for photosynthesis
• How does temperature affect rate of photosynthesis?


  water particles have more energy so evaporation and diffusion are faster
• How does wind affect transpiration?


  wind will blow away molecules and water vapour so removed quickly by air movement
• How does humidity affect transpiration?


  higher the humidity the more water there is in the air so it will not evaporate
• What are guard cells?


  kidney-shaped cells that allow gas exchange to happen
• What controls stomata opening and closing?


  guard cells
• What happens to guard cells in light?


  water enters via osmosis into pairs of guard cells, making the turgid. this opens the stomata
• What happens to stomata in dark?


  Water leaves the guard cells, they lose their turgidity, becoming flaccid and the stomata closes
• Adaptations of xylem cells?


  cells become lignified- hollow and joined together so water can move through

  lignin deposited in spirals-helps withstand pressure of water movement
• Adaptations of phloem cells?


  mitochondria of companion cells supply energy which is used to transport sucrose

  cell walls form sieve plates allowing movement of substances from cell to cell
• Adaptations of a leaf?

  waxy cuticle- layer lipids prevent water loss

  upper epidermis-transparent let light through

  palisade cells-chloroplasts can get light

  stomata-close to stop water los, open to increase transpiration

  large surface are-can absorb more light

  thin-co2 short distance to enter, and oxygen short distance to leave