Download Sensory Neurons - Human Biology and Health - Past Exam and more Exams Human Biology in PDF only on Docsity! Page 1 of 14 ARHOLIADAU EXAMINATIONS SEMESTER 1 EXAMINATIONS 2010 IBERS (BIOLOGICAL SCIENCES) BS12310 HUMAN BIOLOGY AND HEALTH TIME ALLOWED: TWO HOURS ANSWER ALL MULTIPLE CHOICE QUESTIONS INSTRUCTIONS FOR MULTIPLE CHOICE QUESTIONS Answer all multiple choice questions on one optically marked sheet. You must answer each question in the order in which it appears on the question paper. Complete the boxes on the optically marked sheet to give the following details - name, date, subject, module identifier and student number. Student number should be completed by writing the digits in pencil in the top line of the box and then filling in the bar code boxes below with the first digit represented in column 1, the second digit in column 2 and so on. This is done by striking through the little box with a soft pencil as shown in the instructions on the sheet for marking the correct answers. Other instructions are on the sheet, but note the following:- There are five possible answers to each question, only one of them is correct. Record your answers on the optically read sheet by using a soft pencil (HB or softer) to mark the appropriate box thus: Do not tick, cross or ring boxes and do not write elsewhere on the form. 1 mark is given for every correct answer. No marks added/deducted for incorrect answers. No marks added/deducted for blank answers. If you make a mistake on the optically marked sheet, it can be corrected with a soft eraser. Spare sheets are available in the examination hall. Page 2 of 14 1. Which of the following is NOT true regarding the spinal cord? a) Its outer portions are composed of grey matter. b) It is protected by the vertebrae. c) It is involved in reflexes. d) The ascending nerve tracts carry sensory information. e) It transmits nerve impulses between the brain and the rest of the body. 2. Which one of the following statements is correct concerning neurotransmitters? a) Always cause an excitatory effect on the postsynaptic neuron. b) Are action potentials. c) Cause the release of chemicals from the dendrites of a presynaptic neuron. d) Are stored in vesicles in the axon bulb of a presynaptic neuron. e) Are released into a synaptic cleft in response to a graded potential. 3. Which one of the following types of neurons conducts nerve impulses from the central nervous system to organs of the body? a) Sensory. b) Motor. c) Interneurons. d) Both sensory and motor. e) Both sensory neurons and interneurons. 4. The nucleus and organelles of a neuron are located in its a) axon hillock b) cell body c) axon bulb d) dendrite e) axon terminal. 5. Which of the following is TRUE regarding the action potential? a) It will only occur if the sum of graded potentials reaches threshold. b) It results in a small, localized change in the resting potential of a neuron. c) It is caused by hyperpolarization of the neuron’s plasma membrane. d) Potassium ions enter the cell while sodium ions leave the cell. e) The membrane potential during the action potential equals the resting membrane potential. 6. Which one of the following hormones regulates water balance? a) Oxytocin. b) Insulin. c) ADH. d) Thyroxin. e) ACTH. Page 5 of 14 20. The purpose of the secretion of acid into the lumen of the stomach is to a) kill bacteria in food b) break down carbohydrates c) stimulate the conversion of pepsin to pepsinogen d) decrease the rate of digestion e) inhibit the absorption of food into the bloodstream. 21. Which of the following is not true regarding the placenta? a) It allows the exchange of nutrients, gases and antibodies between the mother and foetus. b) Alcohol, cocaine and several non-prescription drugs can cross the placenta and enter foetal circulation. c) The placenta is formed solely of foetal tissue. d) The umbilical cord contains blood vessels that connect the placenta to the embryo’s circulation. e) The chorion and chorionic villi of the embryo form part of the placenta. 22. The first 4 days of human embryonic development occur in the a) uterus b) vagina c) cervix d) oviduct e) ovary. 23. The first point at which the foetus could survive outside the uterus with proper neonatal care is during the _______ month of development. a) eighth b) sixth c) fourth d) seventh e) third. 24. Which of the following is NOT characteristic of the pre-embryo? a) Formation of a morula. b) Appearance of human features. c) Cleavage. d) Implantation in the uterus. e) Formation of a blastocyst. 25. Which of the following structures, characteristic of the embryo after 3 weeks of development, develops into bone, muscle and skin? a) Pharyngeal arches. b) Neural tube. c) Somites. d) Limb buds. e) Neural groove. Page 6 of 14 26. Which of the following is not true regarding skin? a) The stratum basale is the deepest layer of the epidermis. b) The stratum spinosum comprises eight to ten layers of keratinocytes. c) The stratum granulosum contains cells undergoing apoptosis. d) The stratum lucidum contains no keratin and is consequently clear. e) The stratum corneum comprises dead keratinocytes. 27. Which of the following is true regarding skin? a) The dermis consists of several layers of epithelial cells. b) Keratin is a protein in the cells of the epidermis that prevents the cells from reproducing. c) The skin rests on a layer of connective tissue called the hypodermis. d) The dermis of the skin is primarily composed of fat cells. e) Melanocytes produce calcium which strengthens the skin. 28. Dermal papillae are a) sensory hairs of the epidermis b) invaginations of the dermis c) water repellent granules of the stratum granulosum d) capillaries of the dermis e) ducts from the sweat glands. 29. One of the important functions of sebaceous glands is to a) regulate body temperature by evaporation of sweat b) stimulate hair growth c) prevent excessive evaporation from the skin d) kill microbes on the skin surface e) harden the skin to protect against mechanical damage. 30. Wrinkling of the skin through over-exposure to UV radiation is the result of a) overuse of tanning lotions b) permanent damage to small blood vessels of the skin c) excessive stimulation of melanin production d) DNA damage to keratinocytes e) disruption of collagen and elastin fibres of the skin. 31. The amount of blood in an adult human is a) 5L b) 10L c) 1L d) 7L e) 3L. 32. Which of the following plasma proteins is primarily responsible for maintaining an osmotic balance between the extracellular fluid and blood? a) Clotting factors. b) Globulins. c) Haemoglobin. d) Albumins. e) Hormones. Page 7 of 14 33. If a person is blood type O, which of the following antibodies will his body produce? a) Type O antibody. b) Type AB antibody. c) Type A antibody. d) Type B antibody. e) Type A antibody and type B antibody. 34. Which of the following is true regarding the “recycling” of haemoglobin? a) The peptide chains are broken down into their constituent fatty acids. b) The iron atoms are returned to the red bone marrow. c) The heme groups are converted to urine by the kidneys. d) The peptide chains are transported intact to the bone marrow for reuse. e) The heme groups with their iron atoms are transported to the spleen. 35. Which of the following types of white blood cells gives rise to cells that produce antibodies? a) T lymphocytes. b) Monocytes. c) B lymphocytes. d) Neutrophils. e) Eosinophils. 36. Which of the following is not a mechanism that assists the veins in returning blood to the heart? a) Valves inside veins. b) High blood pressure associated with the blood in veins. c) Contraction of skeletal muscle surrounding veins. d) Pressure changes in the thoracic and abdominal cavities caused by breathing. e) Effects of the skeletal muscle pump. 37. The left ventricle has a more muscular wall than the other three chambers of the heart because the left ventricle a) must generate enough blood pressure to pump blood into the aorta b) pumps blood more rapidly than the other chambers c) pumps blood into the atria d) must decrease the amount of pressure on the blood so it can flow more smoothly e) receives blood directly from the major arteries. 38. Heart sounds result from a) the expansion and elastic recoil of arteries b) closing of the heart valves c) contraction of the ventricles d) the flow of blood through the arteries e) the flow of blood as it enters the heart. Page 10 of 14 51. What type of tissue is articular cartilage made of? a) Elastic cartilage. b) Flexible cartilage. c) Hyaline cartilage. d) Fibrous cartilage. e) Brown cartilage. 52. Points of contact between bones are known as a) fractures b) articulations c) tendons d) reticulations e) osteopores. 53. Which of the following is NOT a function of bone? a) Storage of calcium. b) Blood cell production. c) Conduction of nerve impulses. d) Protection. e) Support. 54. Which of the following is NOT true regarding the structure of compact bone? a) The matrix between osteocytes contains deposits of calcium phosphate. b) Osteocytes are located in lacunae. c) Osteocytes do not touch each other but communicate by means of electrical signals. d) Osteocytes are arranged in concentric circles within an osteon. e) The haversian canal contains blood vessels. 55. What is the function of a flexor muscle? a) To bend a joint. b) To straighten a joint. c) To move a body part away from the body midline. d) To move a body part towards the middle of the body. e) To ensure that a joint remains flexible. 56. What is the expected mortality rate as a result of Clostridium tetani infections? a) 40 to 60%. b) 10 to 30%. c) 20 to 50%. d) 50 to 70%. e) 0 to 20%. 57. A skeletal muscle cell a) contains one nucleus b) is usually smaller than other body cells c) has a maximum length of 120mm d) lengthens when its myofibrils shorten e) has myofibrils composed of actin and myosin. Page 11 of 14 58. Which of the following proteins acts as an enzyme in the breakdown of ATP? a) Troponin. b) Actin. c) Tropomyosin. d) Myosin. e) Calmodulin. 59. Which of the following is characteristic of cardiac muscle but not smooth muscle? a) Involuntary contraction. b) Presence of intercalated disks. c) Capable of responding to nervous stimulation. d) Presence of gap junctions between the cells. e) Ability of the cells to contract in a coordinated fashion. 60. What is the approximate residual volume of a normal human lung? a) 5.2L. b) 3.1L. c) 1.2L. d) 0.5L. e) 2.1L. 61. What is the total surface area of the alveoli in an average human lung? a) 50m2. b) 10m2. c) 100m2. d) 120m2. e) 75m2. 62. Which of the following does NOT contribute to the distinctive quality of a voice? a) Shape of the vocal cords. b) Nose and nasal cavity. c) Size of lungs. d) Muscles of the pharynx and tongue. e) Teeth. 63. Which of the following is true regarding inspiration? a) It is a process by which air flows from the lungs. b) The intercostals muscles contract, causing the ribs to move downwards. c) Air pressure in the lungs increases relative to atmospheric pressure. d) The diaphragm flattens as it contracts. e) The pleural cavity volume decreases. Page 12 of 14 64. Which of the following is NOT true regarding bicarbonate? a) The conversion of bicarbonate to carbon dioxide gas occurs in tissues. b) In order to transport carbon dioxide back to the lungs, most of it is converted into bicarbonate. c) Carbonic anhydrase catalyses the conversion of carbon dioxide to carbonic acid. d) Bicarbonate forms when carbonic acid breaks down. e) The conversion of carbon dioxide to carbonic acid occurs inside red blood cells. 65. Approximately what percentage of the total water loss from the body per day is by evaporation within the lung? a) 20%. b) 10%. c) 30%. d) 5%. e) 50%. 66. What percentage of urea is re-absorbed by the kidney after its initial removal from the blood? a) 10%. b) 100%. c) 20%. d) 50%. e) 75%. 67. The detoxification of ammonia and subsequent production of urea occurs in the a) spleen b) kidney c) ureter d) liver e) pancreas. 68. Most reabsorption of water and nutrients from the glomerular filtrate occurs in the a) loop of Henle b) proximal convoluted tubule c) glomerulus d) collecting duct e) distal convoluted tubule. 69. Aldosterone is secreted by the a) pancreas b) hypothalamus c) adrenal gland d) kidney e) posterior pituitary.