Welcome to your OCR AS Biology 3 1. Select the incorrect statement regarding smoking. Smoking of flavoured tobacco called 'shisha' has become fashionable at present. The World Health Organization (WHO) considers smoking to be a disease. Number of smokers in UK and USA has increased sharply in recent decades. Pipes and cigars existed before the manufacture of cigarettes.2. Which does not happen when you inhale? The diaphragm contracts. The intercostal muscles contract. The ribcage drops inwards and downwards. The ribcage expands.3. Which does not happen when you exhale? The intercostal muscles relax. Pressure inside the chest dicreases. The diaphragm relaxes. Volume of the chest decreases.4. Select the correct statement about nicotine. Nicotine influences reward centres in the brain. Nicotine is absorbed slowly by the blood. Nicotine is absent in cigarette smoke. Nicotine is absent in tobacco.5. What is the countercurrent principle in the respiratory system of a fish? The blood flows in the opposite direction to water. The blood flows in the same direction to water. Specialized cells apart from gills act as respiratory surfaces. Blood and water mix together.6. Stomata does not close in which of the following circumstance? Darkness High temperature Low humidity High light intensity7. Select the correct statement about gills. Gills provide a large surface area for respiration. Gills are inefficient respiratory organs. The gills are not supplied with enough blood. Gills have a long diffusion distance.8. What is the correct sequence of breathing in order starting from inhalation? a) Air is forced out of the lungs. b) The diaphragm rises during exhalation. c) The volume of the lung increases and air pressure in the lung decreases. d) Air enters the lungs. e) The volume of lungs decreases and the air pressure in the lungs increases. c, b, e, d, a c, e, a, b, d c, d, b, e, a c, d, e, b, a9. The substance in tobacco which decreases the oxygen carrying capacity of haemoglobin. Nicotine Carbon dioxide Tar Carbon monoxide10. Which is not a main component of cigarette smoke? Ammonia Tar Nicotine Carbon monoxide11. Why do large mammals have difficulties regulating body temperature in hot climates? Difficulty in finding sources of water. They are ectotherms. More heat is lost to the environment. Small surface area to volume ratio.12. An essential feature of alveoli which contributes towards efficient gas exchange. The alveoli are surrounded by capillaries. They have thick walls. Alveoli are less in number. The alveoli are present in the lungs.13. Which is not a method used in examining tumours in the lungs? Colonoscopy Chest X-ray CT scan Bronchoscopy14. Which of the following is a lung disease? Jaundice Appendicitis Cirrhosis Emphysema15. What is the function of mRNA in protein synthesis? Transcripts the base sequence of DNA molecule and carries to the cytoplasm. Associates with a set of proteins to form ribosomes. Deciphers the codons. Unwinds the DNA double helix.16. Select the correct statement regarding water and heat loss in organisms. In smaller organisms, heat loss is less than in large organisms. Heat or water loss is affected by surface area to volume ratio. In large organisms, water loss is more than in small organisms. In smaller organisms, water loss is less than in large organisms.17. Which of the following is a symptom of chronic bronchitis? Sore throat Fever Cough Diarrhea18. Select the incorrect statement about stomata. Stomata allows the outward diffusion of water vapour in transpiration. Stomata show daily rhythm of opening and closing. Stomata does not close at night. Stomata opens during the day.19. Which of the following contains cartilage? Capillary Trachea Alveolus DiaphragmTime is Up!