Biology Paper 1 Key Ideas Flashcards
Why is sodium hydrogen carbonate used instead of water in the photosynthesis practical?
It provides carbon dioxide which is a reactant in photosynthesis
Why is the pondweed left for a couple minutes
To equilibrate in the solution
Define oxygen debt
The amount of oxygen needed to convert lactic acid back into glucose
Define chromosome
Structure of DNA in the nucleus
Define gene
Section of a chromosome that codes for a specific protein
Define osmosis
Diffusion of water from a dilute to more concentrated solution
Define active transport
Movement of substances from dilute to more concentrated requiring energy from respiration
Explain how plant leaves are adapted for exchanging materials
Flat shape,many stomata thin = short diffusion pathway
What’s a negative of using stem cells from embryos?
Destroys potential life
Convert micrometers to millimetres
Divide by 1000 or just x 10 -3
Differences between bacterial and eukaryotic cell
Bacteria has no nucleus,has a strand of DNA instead,bacteria is smaller
Heart pathway (Vincent runs right past peters locker leaving archies)
Vena cava,right atrium,right ventricle,pulmonary artery,pulmonary artery,left atrium,left ventricle,aorta
3 reason why drugs are tested in clinical trials before given to the public
Check for toxicity (harmful),check for efficacy (if it works),check for optimum dosage (how much to take)
Describe the structure and function of xylem tissue (4)
Xylem is made from dead cells,xylem cells have no nucleus/cytoplasm - so the flow of water isn’t restricted
Xylem cells have no end cell walls - allowing easy water flow from roots to leaves
Xylem transports water and is used for transpiration (movement of water r->l for evaporation)
Water only moves in one direction
Where is amylase produced?
Where is protease produced?
Salivary glands
Stomach
What enzymes does the pancreas secrete?
Amylase,protease,lipase
What enzymes does the small intestine secrete?
Carbohydrate,protease,lipase
Why do we have to digest starch?
Large,insoluble molecule so it can’t be absorbed into the blood
