Welcome to your OCR AS Biology 7 Which of the following feature in the veins would help prevent the backflow of blood? Valves Tunica intima Tunica media Tunica externaWhy are blood samples normally taken from veins rather than arteries? Due to the high pressure in them. Due to the low pressure in them. Due to the convenience. Only veins carry the required amount of blood.What happens when the blood enters an artery at low pressure? Walls of the artery widens. Nothing happens. The blood flows back outwards. The artery tries to raise the pressure a bit.Which of the following aids in stretching and recoiling of alveolar walls? Ciliated cells Goblet cells Elastic fibres Secretary cellsCapillaries form a network throughout every tissue in the body except ________. Colon and skin Cornea and cartilage Cornea and skeletal muscles Skin and cartilageWhich of the following is not a function performed by the small intestine? Absorption of mineral ions actively. Absorption of vitamins. Acts as an endocrine gland. Food is converted to chyme.Blood in veins is dark red in colour. What does it imply? Blood inclusive of calcium in high doses. Oxygenation Deoxygenation Blood free of antibodiesWhat is the major method of food absorption in small intestines? Passive absorption Active absorption Simple diffusion Facilitated diffusionCapillary networks are also called the _________. Capillary beds Capillary mesh Capillary tubules VenulesThe feel of 'pulse' in your wrist is due to ________. Circulatory malfunction An artery A capillary A veinWhat is the role of aminopeptidase found in the intestinal juice? Converts small polypeptides into dipeptides and aminoacids. Converts emulsified fat into fatty acids and glycerol. Converts starch into disaccharides. Activates trypsinogen.Which of the following is not a component of gastric juice? Enzyme pepsin Secretin Renin HClWhat is the function of dipeptidases? They digest maltose. They digest sucrose. They digest lactose. They convert dipeptides into aminoacids.A similarity between arteries and veins. Thickness of the wall. Location Composition of the wall. The direction of blood flow.What is the function of enzyme pepsin? Digests protein partially. Dissolves intercellular substances. Converts pepsinogen into pepsin. Digests emulsified fat in milk.Which is not an adaptation of small intestine for food absorption? It is connected to the large intestine. Presence of villi. Long in length. Presence of lacteal ducts.Select the incorrect statement regarding the food digestion in colon. Parasitic micro organisms synthesize vitamin K and folic acid. Micro organisms are destroyed by lymphatic tissues. Faecal matter is formed. Chyme is not chemically digested.Tissue fluid is the result of _______. Leaked platelets Leaked antibodies Leaked WBC Leaked plasmaSelect the incorrect statement regarding tissue fluid. Tissue fluid forms the immediate environment of each individual body cell. Tissue fluid is almost identical in composition to blood plasma. Tissue fluid is not maintained at a constant level within our body. It is through tissue fluid that exchanges of materials between cells and the blood occur.Which of the following principles is not used by the small intestine for absorption? Simple diffusion Active absorption Facilitated diffusion Passive absorption
