Biology Past Papers Aqa As 104 Correctly Answered Questions Latest Update

Explain why some cells contain a mass of DNA between 1 and 2 arbitrary units (1) {Ans: DNA replication taking place / hasn't finished}give two structures of a cell that help with the rapid absorption of glucose. explain how these help (4) {Ans: mitochondria- provide ATP for active transport microvilli- increased SA for diffusion vesicles- bring carrier proteins to membrane}pulmonary ventilation calculation {Ans: breathing rate x tidal volume}suggest why doses of AZT lead to muscle wastage (2) {Ans: -fewer mitochondria so less aerobic respiration -muscle receive less ATP so waste is made}describe and explain the mechanism that causes forced expiration (4) {Ans: -contraction of internal intercostal muscles -relaxation of external intercostal muscles -causes decrease in volume of thorax -air pushed down pressure gradient}name the chemical element found in all amino acids that is NOT found in triglycerides {Ans: nitrogen}