Answer the following question given this paragraph: QUADruplets are four children born at one birth. Q: What are four children born at one birth called? Choices: - triplets - twins - kittens - quadruplets A:
quadruplets
Answer the following question given this paragraph: Spontaneous and Nonspontaneous Processes Processes have a natural tendency to occur in one direction under a given set of conditions. Water will naturally flow downhill, but uphill flow requires outside intervention such as the use of a pump. Iron exposed to the earth's atmosphere will corrode, but rust is not converted to iron without intentional chemical treatment. A spontaneous process is one that occurs naturally under certain conditions. A nonspontaneous process, on the other hand, will not take place unless it is "driven" by the continual input of energy from an external source. A process that is spontaneous in one direction under a particular set of conditions is nonspontaneous in the reverse direction. At room temperature and typical atmospheric pressure, for example, ice will spontaneously melt, but water will not spontaneously freeze. The spontaneity of a process is not correlated to the speed of the process. A spontaneous change may be so rapid that it is essentially instantaneous or so slow that it cannot be observed over any practical period of time. To illustrate this concept, consider the decay of radioactive isotopes, a topic more thoroughly treated in the chapter on nuclear chemistry. Radioactive decay is by definition a spontaneous process in which the nuclei of unstable isotopes emit radiation as they are converted to more stable nuclei. All the decay processes occur spontaneously, but the rates at which different isotopes decay vary widely. Technetium-99m is a popular radioisotope for medical imaging studies that undergoes relatively rapid decay and exhibits a half-life of about six hours. Uranium-238 is the most abundant isotope of uranium, and its decay occurs much more slowly, exhibiting a half-life of more than four billion years (Figure 16.2). Q: What kind of process occurs naturally under certain conditions, unlike its opposite, which will not take place unless it is "driven" by the continual input of energy from an external source? Choices: - controlled process - noticeable process - activation process - spontaneous process A:
spontaneous process
Q: Answer the following question given this paragraph: All objects in the universe have a gravitational attraction to each other ( Figure below ). The strength of the force of gravity depends on two things. They are the mass of the objects and the distance between them. The greater the objects' mass, the greater the force of attraction. As the distance between the objects increases, the force of attraction decreases. Q: The mass of the objects and the distance between them affect the strength of what universal force? Choices: - states of matter - weight - motion - gravity A:
A: gravity
Question: Answer the following question given this paragraph: Platelets You may occasionally see platelets referred to as thrombocytes, but because this name suggests they are a type of cell, it is not accurate. A platelet is not a cell but rather a fragment of the cytoplasm of a cell called a megakaryocyte that is surrounded by a plasma membrane. Megakaryocytes are descended from myeloid stem cells (see Figure 18.4) and are large, typically 50100 m in diameter, and contain an enlarged, lobed nucleus. As noted earlier, thrombopoietin, a glycoprotein secreted by the kidneys and liver, stimulates the proliferation of megakaryoblasts, which mature into megakaryocytes. These remain within bone marrow tissue (Figure 18.12) and ultimately form platelet-precursor extensions that extend through the walls of bone marrow capillaries to release into the circulation thousands of cytoplasmic fragments, each enclosed by a bit of plasma membrane. These enclosed fragments are platelets. Each megakarocyte releases 20003000 platelets during its lifespan. Following platelet release, megakaryocyte remnants, which are little more than a cell nucleus, are consumed by macrophages. Platelets are relatively small, 24 m in diameter, but numerous, with typically 150,000160,000 per L of blood. After entering the circulation, approximately one-third migrate to the spleen for storage for later release in response to any rupture in a blood vessel. They then become activated to perform their primary function, which is to limit blood loss. Platelets remain only about 10 days, then are phagocytized by macrophages. Platelets are critical to hemostasis, the stoppage of blood flow following damage to a vessel. They also secrete a variety of growth factors essential for growth and repair of tissue, particularly connective tissue. Infusions of concentrated platelets are now being used in some therapies to stimulate healing. Q: After entering the circulation, approximately one-third of platelets migrate to what organ for storage, to be released in response to any blood vessel rupture? Choices: - bladder - lungs - kidneys - spleen A:
Answer: spleen
*Question*
Answer the following question given this paragraph: Passive transport is a way that small molecules or ions move across the cell membrane without input of energy by the cell. The three main kinds of passive transport are diffusion (or simple diffusion), osmosis, and facilitated diffusion. Simple diffusion and osmosis do not involve transport proteins. Facilitated diffusion requires the assistance of proteins. Q: What term describes a way that small molecules or ions move across the cell membrane without input of energy by the cell? Choices: - physical transport - impassive transport - immune transport - passive transport A:
**Answer**
passive transport
Answer the following question given this paragraph: Reactions can proceed by themselves if they are exergonic or exothermic, that is if they release energy. The associated free energy of the reaction is composed of two different thermodynamic quantities, enthalpy and entropy. Enthalpy is a measure of the total energy of a thermodynamic system. The change in enthalpy is positive in endothermic reactions, and negative in exothermic processes. Q: Enthalpy is a measure of the total energy of what kind of system? Choices: - macroscopic - planetary - hypodermic - thermodynamic A:
thermodynamic