AQA A Level Biology Mock Paper 2 Q&A, Exams of Advanced Education

Download AQA A Level Biology Mock Paper 2 Q&A and more Exams Advanced Education in PDF only on Docsity! AQA A Level Biology Mock Paper 2 Q&A Exercise causes an increase in heart rate. Describe the role of receptors and of the nervous system in this process - chemoreceptors detect fall in pH send impulses to medulla oblongata more impulses to SAN by sympathetic nervous system Succinic acid dehydrogenase is an enzyme used in the krebs cycle. Suggest one reason for the difference in the staining between the muscle fibres of the control mice and the trained mice - increase aerobic respiration Describe how chemicals which inhibit the decolourisation of DCPIP could slow the growth of weeds - less ATP produced less NADP produced less GP-TP Suggest one way in which an increase in the uptake of phosphate could increase plant growth - used to produce ATP/ADP/phospholipids/DNA/RNA/RuBP/TP/GP in cells Arbuscular mycorrhiza fungi (AMF) are fungi which grow on and into the roots of plants. AMF can increase the uptake of inorganic ions such as phosphate. Suggest one way in which AMF may benefit from their association with plants - provides AMF with amino acids Explain why an increase in shoot biomass can be taken as a measurement of net primary productivity - represents dry mass represents gross production - respiratory losses Each year, a few people with type 1 diabetes are given a pancreas transplant. Pancreas transplants are not used to treat people with type 2 diabetes. Give 2 reasons why pancreas transplants are not used for the treatment of type 2 diabetes - 1. type 2 diabetics can produce insulin 2. can be controlled by diet and exercise Give 3 facts about the action of insulin - activates enzymes involved in the conversion of glucose to glycogen controls the uptake of glucose by regulating the inclusion of channel proteins in the surface membranes of target cells attaches to receptors on the surfaces of target cells Suggest how transcription factors can reprogram cells to form induced pluripotent cells - unipotent cells are reprogrammed by transcription factors which attach to promoter region and stimulate RNA polymerase What is meant by phenotype - the observable characteristics produced by the interaction of the genotype with the environment What is epistasis - the interaction of genes that are not alleles, in particular the suppression of the effect of one such gene by another Describe the role of reverse transcriptase in RT-PCR - converts RNA to complementary DNA (single stranded DNA) Explain the role of DNA polymerase in RT-PCR - joins nucleotides to produce DNA Any DNA sample is hydrolysed by enzymes before the sample is dded to the reaction mixture. Explain why - to remove any DNA present as this DNA would be amplified Suggest one reason why DNA replication stops in PCR - limited number of nucleotides Scientists have used the RT-PCR method to detect the presence of different RNA viruses in patients suffering from respiratory diseases. The scientists produced a variety of primers for this procedure - base sequences differ complementary primers required