Welcome to your Edexcel AS Biology 6 The reason for the closure of A-V valves during the cardiac cycle. Pressure inside the ventricles reaching its lowest. Exceeding ventricular pressure when compared to that of atria. Greater pressure in the aorta than in the left ventricle. Internal pressure of atria being greater than that of the internal pressure of ventricles.Which is not a component found in saliva? HCl Blood clotting factors Salivary amylase LysozymeThe 3 parts which form the small intestine. Duodenum, jejunam, ileum Jejunum,cecum, rectum Duodenum, cecum, ileum Duodenum, ileum, oesophagusWhich part of the digestive system contains the appendix? Duodenum Small intestine Oesophagus CecumWhere is Brunner's glands located? Stomach Duodenum Large intestine Small intestineWhich of the following is not a respiratory pigment? Globulin Haemoglobin Myoglobin HaemoerythrinWhich artery arises from the left ventricle? Pulmonary artery Aorta Ulnar artery Axillary arteryA difference between arteries and arterioles. Arterioles have a great proportion of smooth muscles. Arteries are a type of blood vessel. Arteries can be identified in a closed circulatory system. Arterioles carry nutrients and oxygen to different types of tissues in the body.A distinct feature of a closed circulatory system. The blood is pumped by the heart. The blood flows through veins. Exchange of materials take place through capillary walls. The blood flows away from the heart.A cell in the process of meiosis was seen to have a spindle with sister chromatids being drawn towards opposite poles of the cell. In what stage of meiosis was the cell? Metaphase I Anaphase I Metaphase II Anaphase IIVessels carrying blood towards the heart. Arteries Veins Capillaries TubesStructures found in the small intestine to increase the surface area of absorption. Chief cells Villi Lacteal ducts EpitheliumWhat is the function of lacteal ducts? Increases the surface of absorption. Conduction of triglycerides. Absorption of glucose. Secretion of mucus.A structure present in a villus. G cells Lacteal ducts Appendix Argentaffin cellsWhat is the correct sequence which indicates the mechanism of opening a stomata?a) Volume of guard cell increases.b) H+ transported out of guard cells.c) Water enters guard cells by osmosis.d) K+ diffuses into guard cells.e) Guard cells curve to open stomata.f) Water potential of guard cells falls.g)K+ channels open. b, d, f, g, a, e, c b, g, d, f ,c ,a, e g, f, e, c, b, d, a e, a, c, f, g, d, bWhich of the following are lipid soluble vitamins?a) Vitamin Eb) Vitamin Bc) Vitamin Cd) Vitamin D c, d & a a & d only b & c only b, c & dWhich type of cells secrete HCl in the stomach? Chief cells Argentaffin cells Parietal cells Mucous neck cellsHow does the food bolus travel upto the stomach? By gag reflex By ciliary movement By gastrocolic reflex By peristalsis movementEssential components of a circulatory system. A circulatory fluid, veins and arteries A circulatory fluid and heart Blood vessels and heart A circulatory fluid, blood vessels and heartTime is Up!