Transport in Humans and Animals

Question 7:Coronary heart disease is the main cause of death in our country. The following factors can increase the risk of an individual contracting this disease:• smoking• unbalanced diet• unhealthy lifestyleExplain how these factors can contribute to coronary heart disease. Answer:Smoking• Cigarette smoke contains nicotine.• Nicotine causes addiction. • Nicotine shrinks blood vessels.• Nicotine increases blood … Read more

Question 5:One of the lymphatic vessels of an individual is clogged.(a) Explain the effects on the lymphatic system of the individual.(b) Explain what will happen if the lymphatic vessel in the leg is clogged? Answer:(a) Tissue fluid accumulates in the blocked vessels and cannot be returned to the blood circulatory system. The individual will suffer … Read more

Question 1:An accident victim with blood group B needs an immediate blood transfusion. Is it safe for the patient to receive blood from individuals with the blood group O? Explain why. Answer:Yes. Individuals with blood group O do not have antigen A or B on their red blood cells. They can donate blood to individuals … Read more

Question 1:How do parasitic infections happen? Answer:The parasitic infection that transmit the parasitic worm Brugia sp. can occur through mosquito bite. Question 2:Explain what would happen when the tissue fluid fails to return to the blood circulatory system. Answer:If excess fluid is not returned to the bloodstream, body tissues become swollen due to excessive fluid … Read more

Question 1:Name the two main lymphatic vessels. Answer:Right lymphatic duct and thoracic duct Question 2:State three main functions of the lymphatic system. Answer:The lymphatic system has three main functions:• The collection of excess tissue fluid to be returned to the bloodstream• The transport of lipids from the small intestine to the bloodstream• Body defence: Lymph … Read more

Question 1:What is the meaning of myocardial infarction? Answer:Heart attack Question 2:Explain how stroke happens. Answer:Stroke occurs when a blood clot impedes blood flow to the brain. Question 3:In your opinion, what are the factors that contribute to an individual’s risk of getting cardiovascular disease? Answer:A diet rich in lipids and low in fibre, lack … Read more

Question 1:State the blood group which is the universal donor. Answer:Blood group O Question 2:Predict what will happen if the blood group of both recipient and donor is not compatible. Answer:The blood of the recipient will undergo agglutination. Question 3:Three babies P, Q and R have blood groups B, O and AB respectively. Three pairs … Read more

Question 1:At the end of the blood clotting mechanism, fibrin will be formed to trap erythrocytes. Explain the meaning of fibrin and its function. Answer:Fibrin is the strand of protein fibre that prevents blood loss when a person is wounded, and entry of microorganisms such as bacteria and foreign substances into the blood. Question 2:Describe … Read more

Question 1:Name the main heart pacemaker. Answer:Sinoatrial node Question 2:What does the term myogenic mean? Answer:Myogenic means the heart contracts and relaxes without receiving any impulse signal from the nervous system. Question 3:Explain why a person who stands too long may faint. Answer:The blood flow back to the heart requires the contraction of skeletal muscles … Read more

Question 1:What is the function of the bicuspid valve? Answer:The bicuspid valve prevents the backflow of blood to the left atrium when the left ventricle contracts. Question 2:Explain why some individuals feel nauseous and faint immediately after donating blood?Why do some blood donors need to take iron pills? Answer:After donating blood, the reduction of blood … Read more