BIO 251 Questions and Answers

BIO 251 Questions and Answers Part 1 of 1 - Part 1 100.0/ 100.0 Points From chapter 18 (18.1-18.6) Question 1 of 20 5.0/ 5.0 Points Which of the following is/are correct in describing thrombosis:  A. A condition characterized by excessive numbers of platelets that increases the risk for excessive clot formation, a condition known as thrombosis.  B. Thrombosis is a very common, always harmless condition that occurs in the body.  C. A thrombosis is always harmless because the thrombus which is formed always stays in a blood vessel precisely where it formed.  D. The blood stream contains several different anticoagulants that will result in the complete, normal breakdown of a thrombus.  E. Two of the above are correct. Feedback: Good work; your answer is correct! Question 2 of 20 5.0/ 5.0 Points Which of the following is/are true of platelets?  A. They arise from cells called megakaryocytes.  B. They do not contain a nucleus.  C. They play an important part in the clotting of blood.  D. They are not cells.  E. All of the above are true. Feedback: Good work; your answer is correct! Question 3 of 20 5.0/ 5.0 Points Which of the following is/are important in the process named coagulation?  A. A process which can reverse coagulation, named anticoagulation, can only occur when one or more medications are administered to the body.  B. Coagulation is a very simple and straight-forward series of only two or three steps.  C. Coagulation is a complicated cascade of reactions that result in the formation of a mesh of fibrin.  D. Neither an excess number of platelets nor having many too few platelets in the blood stream will cause any serious reaction.  E. Coagulation can only occur in the presence of two or three different “clotting factors.” Feedback: Good work; your answer is correct! Question 4 of 20 5.0/ 5.0 Points What is the typical lifespan of a leukocyte?  A. The lifespan of a leukocyte is extremely variable, measuring in hours to years or decades.  B. The lifespan of a leukocyte typically is measured only in hours or days.  C. Because all leukocytes are unable to undergo mitosis (cell division), their lifespan is usually only a few seconds.  D. The lifespan of a leukocyte is approximately 120-150 days.  E. Many leukocytes can live indefinitely if they are in well-protected locations. Feedback: Good work; your answer is correct! Question 5 of 20 5.0/ 5.0 Points Which of the following is true of leukocytes?  A. They are very similar in appearance and function as red blood cells.  B. Leukocytes are smaller than and more numerous than red blood cells.  C. Like red blood cells, mature leukocytes also lack a nucleus and other intracellular organelles.  D. Leukocytes always remain in circulation throughout the body.  E. The leukocyte is a major component of the body’s defenses against disease. Feedback: Good work; your answer is correct! Question 6 of 20 5.0/ 5.0 Points Which of the following is/are true of red blood cells?  A. Their anatomical name is also erythrocyte.  B. In their mature form, they do not contain a nucleus.  C. Immature erythrocytes that may still contain fragments of organelles are called reticulocytes.  D. They contain one molecule of hemoglobin. 