Aqa A-Level Biology Paper 1 Study Guide Questions And Correct Answers

what are the roles of lipids? {Ans: 1. source of energy 2. waterproofing 3. insulation 4. protection}describe the process of inspiration {Ans: external intercostals contract internal intercostals relax ribs move up and outwards, increasing thorax volume diaphragm contracts, further increasing thorax volume air pressure in lungs becomes lower than atmospheric pressure, so air is forced in}where is lactose produced? {Ans: pancreas, small intestine}what purpose does the structure of amylopectin serve? {Ans: more surface area for enzymes to work on, thus glucose molecules can be released at a much quicker rate.}how is tissue fluid formed {Ans: high hydrostatic pressure at arterial end due to contractions of ventricles this causes tissue fluid to be forced out of the blood plasma this is ultrafiltration}define habitat {Ans: the place where an organism normally lives}what are the advantages of an electron microscope? {Ans: electron beam has a short wavelength and the microscope can therefore has high resolution. the negatively charged beam can be focused using electromagnets.}what is a vaccine? {Ans: Contains antigen / proteins / dead / weakened microorganism / pathogen / virus / bacteria; Stimulates production of antibodies / plasma cells / memory cells}explain mass flow