Q: When a wave travels down a string, the string vibrates up and down at right angles to the wave's what? Read this paragraph and choose the correct option from the provided answers: A: The wave travels down the string to the end. The string vibrates up and down at right angles to the direction of the wave. Choices: - frequency - pressure - gravity - direction A:
direction

Q: What do you call any substance that opposes coagulation? Read this paragraph and choose the correct option from the provided answers: Plasma Anticoagulants An anticoagulant is any substance that opposes coagulation. Several circulating plasma anticoagulants play a role in limiting the coagulation process to the region of injury and restoring a normal, clot-free condition of blood. For instance, a cluster of proteins collectively referred to as the protein C system inactivates clotting factors involved in the intrinsic pathway. TFPI (tissue factor pathway inhibitor) inhibits the conversion of the inactive factor VII to the active form in the extrinsic pathway. Antithrombin inactivates factor X and opposes the conversion of prothrombin (factor II) to thrombin in the common pathway. And as noted earlier, basophils release heparin, a short-acting anticoagulant that also opposes prothrombin. Heparin is also found on the surfaces of cells lining the blood vessels. A pharmaceutical form of heparin is often administered therapeutically, for example, in surgical patients at risk for blood clots. Choices: - dissolvent - antibodies - toxin - anticoagulant A:
anticoagulant

Q: What part of blood releases clotting factors? Read this paragraph and choose the correct option from the provided answers: Platelets ( Figure below ) are very small, but they are very important in blood clotting. Platelets are not cells. They are sticky little pieces of larger cells. Platelets bud off large cells that stay in the bone marrow. When a blood vessel gets cut, platelets stick to the injured areas. They release chemicals called clotting factors, which cause proteins to form over the wound. This web of proteins catches red blood cells and forms a clot. This clot stops more blood from leaving the body through the cut blood vessel. The clot also stops bacteria from entering the body. Platelets survive in the blood for ten days before they are removed by the liver and spleen. Choices: - hemoglobin - white blood cells - erythrocytes - platelets A:
platelets