AQA A Level Biology Past Paper Questions

Phospholipids in a plasma membrane are arranged in a [blank_start]bilayer[blank_end] and have [blank_start]hydrophilic[blank_end] phosphate heads and [blank_start]hydrophobic[blank_end] lipid tails.

Risk factors associated with coronary heart disease

During a heart attack areas of heart muscle are deprived of [blank_start]oxygen[blank_end] because of a reduced blood flow in the [blank_start]coronary arteries[blank_end] so they cannot carry out [blank_start]aerobic[blank_end] respiration.

How bacteria are destroyed by phagocytes: Phagocytes form a [blank_start]phagosome[blank_end] around the bacteria. Lysosome empties its contents into the [blank_start]phagosome[blank_end] where [blank_start]lysozyme[blank_end] is released with [blank_start]hydrolyses[blank_end] teh bacteria.

An inhibitor of amylase is added to some food. How could this lower the blood glucose concentration? Fewer [blank_start]enzyme-substrate[blank_end] complexes are formed therefore less starch is digested to [blank_start]maltose[blank_end] meaning less glucose is formed which will lead to a reduced absorption of [blank_start]glucose[blank_end].

Fibrosis can cause changes to FEV since [blank_start]scar[blank_end] tissue has developed. [blank_start]Scar[blank_end] tissue cannot [blank_start]recoil[blank_end] which will mean that inhalation is [blank_start]restricted[blank_end].

Whole cell vaccines could cause harmful side effects since some bacteria may still be [blank_start]alive[blank_end] so the bacteria could [blank_start]reproduce[blank_end]. Also the [blank_start]toxins[blank_end] may not be affected by the heat which was used in the process of attenuating the virus.

Competitive inhibitors have a [blank_start]similar[blank_end] shape to the enzyme's substrate so can bind to the [blank_start]active site[blank_end]. They [blank_start]can[blank_end] be overcome by adding more substrate. Non-competitive inhibitors bind to a [blank_start]second active site[blank_end] which will [blank_start]alter[blank_end] the shape of the active site of the enzyme. These [blank_start]cannot[blank_end] be overcome by adding more substrate.

A hierarchy contains groups within [blank_start]groups[blank_end] with [blank_start]no[blank_end] overlap between groups.

Independent segregation in meiosis produces [blank_start]haploid[blank_end] cells and will arrange the homologous pairs [blank_start]randomly[blank_end].

Selective breeding could cause [blank_start]inbreeding[blank_end] and the [blank_start]higher[blank_end] possibility of mutation being passed on.

A shift to the right in an oxygen dissociation curve will mean that the heamoglobin will have a [blank_start]lower[blank_end] affinity for oxygen which means that oxygen can be [blank_start]unloaded[blank_end] at respiring cells so the rate of respiration will be [blank_start]higher[blank_end].