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A gastrovascular cavity…. Functions in both digestion and distribution of nutrients. All of the above. Is found in cnidarians and annelids. Has a single opening for ingestion and elimination, but a separate opening for gas exchange.
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A gastrovascular cavity… • Functions in both digestion and distribution of nutrients • All of the above • Is found in cnidarians and annelids • Has a single opening for ingestion and elimination, but a separate opening for gas exchange
Which of the following is NOT a similarity between open and closed circulatory systems? • Some of the circulation of blood is a result of movements of the body • All tissues come into close contact with the circulating body fluid so that the exchange of nutrients and wastes can take place • Some sort of pumping device helps to move blood through the body • The blood and interstitial fluid are distinguishable from each other
A heartbeat in humans is initiated by the • AV node • None of the above • SA node • Superior and inferior vena cavae
If all the body’s capillaries were open at one time… • Resistance to blood flow would increase • The amount of blood returning to the heart would increase • Blood pressure would fall dramatically • Blood would move too rapidly through the capillary beds
Fibrinogen is… • A cell fragment involved in the blood clotting mechanism • Both B and C • A blood protein that escorts lipids through the circulatory system • A blood protein that is converted to fibrin to form a blood clot
In countercurrent exchange… • Oxygen is exchanged for carbon dioxide • The capillaries of the lung pick up more oxygen than do tissue capillaries • The flow of fluids in opposite directions maintains a favorable diffusion gradient along the length of an exchange surface • Double circulation keeps oxygenated and deoxygenated blood separate
In which vessel would blood pressure be the highest? • Pulmonary vein • Aorta • Vena cava • Right atrium
In which vessel would velocity of blood flow be the lowest? • Pulmonary capillaries • Vena cava • Left ventricle • Pulmonary vein
Of these structures, which would have the thickest muscle layer? • Right atrium • Vena cava • Aorta • Left ventricle
The nurse tells you that your blood pressure is 112/70. What does the 70 refer to? • The velocity of blood during diastole • The diastolic pressure from the recoil of the arteries • Your heart rate • The systolic pressure from ventricular contraction
Which of the following is incorrectly paired with its effect? • Histamine – Causes blood vessels to dialate • Lysozyme – attacks cell walls of bacteria • Gastric juice – kills bacteria in the stomach • Vaccination – creates passive immunity
Antibodies are… • Proteins circulating in the blood that tag foreign cells for destruction • B and C are both correct • Proteins embedded in T-cell membranes • Proteins that consist of two light and two heavy polypeptide chains
A secondary immune response is more rapid and greater in effect than a primary immune response because… • Chemical signals cause the rapid accumulation of phagocytic cells • The secondary response is an active immunity, whereas the primary one was a passive immunity • Memory cells respond to the pathogen and rapidly clone more effector cells • Helper T-cells are available to activate other blood cells
A transfusion of type B blood given to a person who has type A blood would result in • The recipient’s B antigens reacting with the donated anti-B antibodies • No reaction, because B is a universal donor type of blood • The recipient's anti-B antibodies reacting with the donated red blood cells • The recipient forming both anti-A and anti-B antibodies
Which of the following destroys a target cell by phagocytosis? • Cytotoxic T-cell • Plasma cells • Neutrophil • Natural Killer cell
Clonal selection is responsible for the… • Proliferation of clones of effector and memory cells specific for an encountered antigen • Formation of cell cultures in the commercial production of monoclonal antibodies • Recognition of class I MHC molecules by cytotoxic T-cells • Rearrangement of antibody genes for the light and heavy chains
All of the following are involved with innate immunity except… • Chemicals that attract phagocytes • The inflammatory response • Plasma cells • Antimicrobial proteins such as lysozymes
Helper T-cells play which of the following roles in an acquired immune response? • Produce interferons and histamines that help initiate a specialized inflammatory response • Bind to class I MHC molecules and activate complement proteins to attack and lyse cancer cells • Present antigens of an engulfed pathogen in its class II MHC molecules to B-cells, which are then stimulated to develop into a clone of plasma cells. • Activate both the humoral and cell-mediated immunities by releasing cytokines after recognizing class II MHC molecule-antigen complexes on an antigen-presenting cell.
What accounts for the huge diversity of antigens to which B cells can respond? • The rearrangement of the antibody genes during development results in millions of possible combinations of randomly combined light and heavy polypeptide chains • B cells have thousands of copies of antibodies bound to their plasma membranes • The antibody genes have millions of alleles • The antigen-binding sites at the arms of the molecule can assume a huge diversity of shapes in response to the specific antigen encountered
A freshwater fish would be expected to… • Produce copious quantities of dilute urine • Have scales that reduce water loss to the environment • Pump salt out through salt glands in the gills • Diffuse urea across the epithelium of the gills
Which is the correct pathway for the passage of urine in vertebrates? • Renal vein—renal ureter—bladder--urethra • Cortex—medulla—bladder--ureter • Collecting tubule—Ureter—bladder--urethra • Nephron—urethra—bladder--ureter
The process of reabsorption in the formation of urine ensures that… • Drugs and other poisons are removed from the blood • Glucose, salts, and water are returned to the blood • Excess H+ is removed from the blood • Urine is always hyperosmotic to interstitial fluid
What is the mechanism for the filtration of blood within the nephron? • Both active and passive secretion of ions, toxins, and NH3 into the tubule • A lower osmotic pressure in bowman’s capsule compared to that in the glomerulus • The active transport of Na+ and glucose, followed by osmosis • High hydrostatic pressure of the blood forcing water and small molecules out of the capillary
Which of the following hormones is incorrectly paired with its origins? • Growth hormone – anterior pituitary • TSH - Thyroid • Releasing hormones - hypothalamus • Progestins - ovary
Which of the following is an example of a positive feedback mechanism? • The ability of the neurotransmitter acetylcholine to cause skeletal muscle to contract, heart muscle to relax, and cells of the adrenal medulla to secrete epinephrine. • The action of secretin on the pancreas, stimulating the release of bicarbonate • The liver’s production of insulin-like growth factors in response to growth hormone, which promote skeletal growth • Prostaglandins released from placental cells promoting muscle contraction during childbirth, with muscle contractions stimulating more prostaglandin release
Ecdysone… • Is involved in metamorphosis in amphibians • Is secreted by prothoracic glands in insects and triggers molts and development of adult characteristics • Is a steroid hormone produced in insects that promotes retention of larval characteristics • Is a hormone secreted from specialized neurons that triggers the formation of a pupa
The anterior pituitary… • Receives releasing and inhibiting hormones from the hypothalamus through portal vessels connecting capillary beds • Is responsible for nervous and hormonal stimulation of the adrenal glands • Stores oxytocin and ADH produced by the hypothalamus • Produces several releasing and inhibiting hormones
Which of the following hormones is not involved with increasing the blood glucose concentration? • epinephrine • insulin • glucagon • glucocorticoids
Which of the following is not true of norephinephrine? • It serves as a neurotransmitter • All of the above • It is secreted by the adrenal medulla • It is part of the fight-or-flight response
The function of the corpus luteum is to… • Produce progesterone and estradiol • Maintain pregnancy by production of human gonadotropin • Nourish and protect the egg cell • Produce estradiol and disintegrate following ovulation
Which of the following hormones is incorrectly paired with its function? • Oxytocin – stimulates uterine contractions during birth • FSH – acts on sertoli cells that nourish sperm, promoting spermatogenesis • Androgens – responsible for primary and secondary male sex characteristics • Estradiol – responsible for secondary female sex characteristics
How does meiosis differ in the production of human sperm and ova? • Meiosis occurs in the testes of males but in the oviducts of females • Meiosis is an uninterrupted process in males, whereas it resumes when a follicle matures and is only completed in human females when a sperm penetrates the egg cell. • Each meiototic division produces four sperm but only two ova • Primary oocytes stop dividing by mitosis before birth, whereas male stem cells continue to divide throughout life
In what location does fertilization usually take place in a human female? • Oviduct • Cervix • Ovary • Uterus
Which hormone stimulates ovulation and the development of the corpus luteum? • FSH • Progesterone • LH • hCG
Which hormone is produced by the developing follicle? • Progesterone • FSH • Estradiol • LH
Which hormone is produced by by the embryo and is necessary for maintaining a pregnancy? • FSH • hCG • LH • Progesterone
Which hormone is produced by the corpus luteum and later by the placenta and is responsible for maintaining a pregnancy? • progesterone • FSH • Estradiol • LH
Which of the following is/are involved in triggering and maintaining labor? • Oxytocin produced by fetus and mother, and prostaglandins produced by the placenta • Prolactin produced by the fetus and mother • hCG produced by the fetus • A drop in progesterone caused by the disintegration of the corpus luteum
Which of the following is not true of the resting potential of a typical neuron? • There are concentration gradients with more sodium outside the cell and a higher potassium concentration inside the cell • It results from the combined equilibrium potentials of potassium and sodium. • The inside of the cell is more negative than the outside • It is formed by the sequential opening of voltage-gated channels
After the depolarization of an action potential, the fall in the membrane potential occurs due to the… • Closing of potassium and sodium channels • Opening of voltage-gated potassium channels and the closing of sodium inactivation gates. • Closing of sodium inactivation gates • Refractory period in which the membrane is hyperpolarized
Which of the following is incorrectly paired with its function? • Schwann cells – create myelin sheath around axon • Synaptic terminal – receptor that is part of an ion channel that is keyed to a specific neurotransmitter • Axon hillock – region of neuron where action potential originates • Synapse – space between presynaptic and post-synaptic cell into which neurotransmitter is released
How is an increase in the strength of a stimulus communicated by a neuron? • The frequency of action potentials generated along the neuron increases • All action potentials are the same the nervous system cannot discriminate between different strengths of stimuli. • The spike of the action potential reaches a higher voltage • The length of an action potential increases
Why is signal transmission faster in myelinated axons? • These axons use electrical synapses rather than chemical synapses • These axons are thicker and provide less resistance to voltage flow. • These axons are thinner, and there is less resistance to the voltage flow. • The action potential can jump from node to node along the insulating myelin sheath.