Q: Q: These microorganisms are abundant in the human digestive track and serve many roles. what are they? Read this paragraph and choose the correct option from the provided answers: Bacteria provide vital ecosystem services. They are important decomposers. They are also needed for the carbon and nitrogen cycles. There are billions of bacteria inside the human intestines. They help digest food, make vitamins, and play other important roles. Humans also use bacteria in many other ways, including:. Choices: - antioxidants - pathogens - tumors - bacteria A:
A: bacteria

Q: Q: Urea and carbon dioxide are molecules with how many carbon atoms? Read this paragraph and choose the correct option from the provided answers: Choices: - even number - four - two - one A:
A: one

Q: Q: What's the name for an atom that has gained or lost an electron? Read this paragraph and choose the correct option from the provided answers: Atoms cannot only gain extra electrons. They can also lose electrons. In either case, they become ions . Ions are atoms that have a positive or negative charge because they have unequal numbers of protons and electrons. If atoms lose electrons, they become positive ions, or cations. If atoms gain electrons, they become negative ions, or anions. Consider the example of fluorine (see Figure below ). A fluorine atom has nine protons and nine electrons, so it is electrically neutral. If a fluorine atom gains an electron, it becomes a fluoride ion with an electric charge of -1. Choices: - an photon - isotope - neutrino - an ion A:
A: an ion

Q: Q: Endoscopes are used to explore the body through various orifices or these? Read this paragraph and choose the correct option from the provided answers: Bundles of fibers can be used to transmit an image without a lens, as illustrated in Figure 25.15. The output of a device called an endoscope is shown in Figure 25.15(b). Endoscopes are used to explore the body through various orifices or minor incisions. Light is transmitted down one fiber bundle to illuminate internal parts, and the reflected light is transmitted back out through another to be observed. Surgery can be performed, such as arthroscopic surgery on the knee joint, employing cutting tools attached to and observed with the endoscope. Samples can also be obtained, such as by lassoing an intestinal polyp for external examination. Fiber optics has revolutionized surgical techniques and observations within the body. There are a host of medical diagnostic and therapeutic uses. The flexibility of the fiber optic bundle allows it to navigate around difficult and small regions in the body, such as the intestines, the heart, blood vessels, and joints. Transmission of an intense laser beam to burn away obstructing plaques in major arteries as well as delivering light to activate chemotherapy drugs are becoming commonplace. Optical fibers have in fact enabled microsurgery and remote surgery where the incisions are small and the surgeon's fingers do not need to touch the diseased tissue. Choices: - dermal tears - major incisions - ocular cavity - minor incisions A:
A: minor incisions