Answer the following question given this paragraph: The existence of quarks was first proposed in the 1960s. Since then, scientists have done experiments to show that quarks really do exist. In fact, they have identified six different types of quarks. However, much remains to be learned about these tiny, fundamental particles of matter. They are very difficult and expensive to study. If you want to learn more about them, including how they are studied, the URL below is a good place to start. Q: The existence of what tiny, fundamental particles of matter was first proposed in the 1960s? Choices: - atoms - molecules - neutrons - quarks A:
quarks
(Question)
Answer the following question given this paragraph: Things Great and Small Nuclear Decay Helps Explain Earth's Hot Interior A puzzle created by radioactive dating of rocks is resolved by radioactive heating of Earth's interior. This intriguing story is another example of how small-scale physics can explain large-scale phenomena. Radioactive dating plays a role in determining the approximate age of the Earth. The oldest rocks on Earth solidified about 3.510 9 years agoa number determined by uranium-238 dating. These rocks could only have solidified once the surface of the Earth had cooled sufficiently. The temperature of the Earth at formation can be estimated based on gravitational potential energy of the assemblage of pieces being converted to thermal energy. Using heat transfer concepts discussed in Thermodynamics it is then possible to calculate how long it would take for the surface to cool to rock9 9 formation temperatures. The result is about 10 years. The first rocks formed have been solid for 3.510 years, so that 9 the age of the Earth is approximately 4.510 years. There is a large body of other types of evidence (both Earth-bound and solar system characteristics are used) that supports this age. The puzzle is that, given its age and initial temperature, the center of the Earth should be much cooler than it is today (see Figure 31.26). Q: What method plays a role in determining the approximate age of the earth and makes use of uranium? Choices: - fuel dating - carbon dating - waste dating - radioactive dating A:
(Answer)
radioactive dating
Ques: Answer the following question given this paragraph: Cell division is how organisms grow and repair themselves. It is also how many organisms produce offspring. For many single-celled organisms, reproduction is a similar process. The parent cell simply divides to form two daughter cells that are identical to the parent. In many other organisms, two parents are involved, and the offspring are not identical to the parents. In fact, each offspring is unique. Look at the family in Figure below . The children resemble their parents, but they are not identical to them. Instead, each has a unique combination of characteristics inherited from both parents. Q: How do organisms grow and repair themselves? Choices: - cell death - mutation - symbosis - cell division A:
Ans: cell division
(Q).
Answer the following question given this paragraph: Chloride ions are important in neutralizing positive ion charges in the body. If chloride is lost, the body uses bicarbonate ions in place of the lost chloride ions. Thus, lost chloride results in an increased reabsorption of bicarbonate by the renal system. Q: Why does the body react to a loss of chloride ions? Choices: - increased tricarbonate reabsorption - decreased bicarbonate reabsorption - decreased tricarbonate reabsorption - increased bicarbonate reabsorption A:
(A).
increased bicarbonate reabsorption
Ques:Answer the following question given this paragraph: Interventional Radiologist The controlled use of radioisotopes has advanced medical diagnosis and treatment of disease. Interventional radiologists are physicians who treat disease by using minimally invasive techniques involving radiation. Many conditions that could once only be treated with a lengthy and traumatic operation can now be treated non-surgically, reducing the cost, pain, length of hospital stay, and recovery time for patients. For example, in the past, the only options for a patient with one or more tumors in the liver were surgery and chemotherapy (the administration of drugs to treat cancer). Some liver tumors, however, are difficult to access surgically, and others could require the surgeon to remove too much of the liver. Moreover, chemotherapy is highly toxic to the liver, and certain tumors do not respond well to it anyway. In some such cases, an interventional radiologist can treat the tumors by disrupting their blood supply, which they need if they are to continue to grow. In this procedure, called radioembolization, the radiologist accesses the liver with a fine needle, threaded through one of the patient's blood vessels. The radiologist then inserts tiny radioactive "seeds" into the blood vessels that supply the tumors. In the days and weeks following the procedure, the radiation emitted from the seeds destroys the vessels and directly kills the tumor cells in the vicinity of the treatment. Radioisotopes emit subatomic particles that can be detected and tracked by imaging technologies. One of the most advanced uses of radioisotopes in medicine is the positron emission tomography (PET) scanner, which detects the activity in the body of a very small injection of radioactive glucose, the simple sugar that cells use for energy. The PET camera reveals to the medical team which of the patient's tissues are taking up the most glucose. Thus, the most metabolically active tissues show up as bright "hot spots" on the images (Figure 2.6). PET can reveal some cancerous masses because cancer cells... Q: One of the most advanced uses of what in medicine is the positron emission tomography scanner, which detects the activity in the body of a very small injection of radioactive glucose? Choices: - radionuclides - quarks - membranes - radioisotopes A:

Ans:radioisotopes
Ques:Answer the following question given this paragraph: Q: The carbon cycle can be thought of in terms of two interdependent cycles - cellular respiration and what else? Choices: - glycolysis - spermatogenesis - pollination - photosynthesis A:

Ans:
photosynthesis