GCSE AQA BIOLOGY Organisation Exam Questions and Answers

GCSE AQA BIOLOGY Organisation Exam Questions and Answers cell organisation - Answer️️ -similar cells are organised into tissues that perform a function, such as: -muscle -glandular -epithelial different tissues are organised together to make organs that perform a specific function, such as -stomach is made from all of the above organs are organised into organ systems that perform a range of functions -digestive system enzymes - Answer️️ -biological catalysts that control reactions within the body. they are large proteins (long chains of amino acids folded into unique shapes) they have active sites with unique shapes-they only catalyse one reaction enzyme conditions - Answer️️ -enzymes must be at the right temperature and pH or their bonds can break and become denatured digestive enzymes - Answer️️ -starch broken down into sugars through amylase protein broken down into amino acids through proteases lipids broken down into glycerol and fatty acids through lipase salivary glands - Answer️️ -produce amylase stomach - Answer️️ --pummels food -produces protease (pepsin) -produces hydrochloride acid, which: -kills pathogens -provides correct pH for pepsin liver - Answer️️ --produces bile, which is used to neutralise the small intestine so that digestive enzymes can work effectively pancreas - Answer️️ --produces amylase, protease and lipids small intestine - Answer️️ -produces amylase, lipids and protease food tests - Answer️️ -sugars: -use benedicts solution -in water bath of 75 degrees c -colour change blue to green to yellow to red starch: -use iodine -shake gently, blue/black colour indicates starch is present -orange/brown colour indicates it is not proteins: -use biuret solution -shake gently, pink/purple colour indicates proteins -blue colour indicates no proteins lipids/ -sudan III -shake gently, if red layer forms on top, lipids are present -if not, no lipids lungs - Answer️️ -where gas exchange takes place through alveoli alveoli - Answer️️ -blood passes next to it, it has a high concentration of carbon dioxide and low concentration of oxygen. gases diffuse through and blood is taken away to go to cells. carbon dioxide exhaled. heart - Answer️️ -double circulatory system - left side pumps blood to body, right side pumps blood to lungs. blood flows into atria (through either vena cava or pulmonary vein) atria contract forcing blood into ventricles. ventricles contract and are pushed through valves and out into body through either pulmonary artery or aorta, and returns through veins. pacemaker creates electrical impulses that controls he