Answer the following question given this paragraph: Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for so und na vigation and r anging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a receiver (see Figure below ). It sends out ultrasound waves and detects reflected waves that bounce off underwater objects or the bottom of the water. If you watch the video at the URL below, you can see how sonar is used on a submarine. Q: What tool, used to locate underwater objects, utilizes ultrasound in a way that is similar to echolocation? Choices: - GPS - radar - scanning - sonar A:
sonar
Answer the following question given this paragraph: The fishing float in Figure below bobs on the surface of the water. The fish in the figure is suspended in the water near the surface. Why do the float and fish stay on or near the surface? Why don't they sink? The answer is buoyancy, another property of fluids. Q: What property of fluids causes something to stay on or near the surface of water? Choices: - density - strength - weight - buoyancy A:
buoyancy
Q: Answer the following question given this paragraph: The variation in a sample can be represented by the range, or the total spread of values. Q: The variation in a sample can be represented by what quantity, which means the total spread of values? Choices: - variety - mode - median - range A:
A: range
Question: Answer the following question given this paragraph: Potassium Concentration Glial cells, especially astrocytes, are responsible for maintaining the chemical environment of the CNS tissue. The concentrations of ions in the extracellular fluid are the basis for how the membrane potential is established and changes in electrochemical signaling. If the balance of ions is upset, drastic outcomes are possible. Normally the concentration of K+ is higher inside the neuron than outside. After the repolarizing phase of the action potential, K+ leakage channels and the Na+/K+ pump ensure that the ions return to their original locations. Following a stroke or other ischemic event, extracellular K+ levels are elevated. The astrocytes in the area are equipped to clear excess K+ to aid the pump. But when the level is far out of balance, the effects can be irreversible. Astrocytes can become reactive in cases such as these, which impairs their ability to maintain the local chemical environment. The glial cells enlarge and their processes swell. They lose their K+ buffering ability and the function of the pump is affected, or even reversed. One of the early signs of cell disease is this "leaking" of sodium ions into the body cells. This sodium/potassium imbalance negatively affects the internal chemistry of cells, preventing them from functioning normally. Q: One of the early signs of cell disease is this "leaking" of what into the body cells? Choices: - proteins - potassium ions - glucose - sodium ions A:
Answer: sodium ions
*Question*
Answer the following question given this paragraph: Adult frogs are characterized by long hind legs, a short body, webbed finger-like parts, and the lack of a tail. They also have a three-chambered heart, as do all tetrapods except birds and mammals. Most frogs live part of the time in water and part of the time on land. They move easily on land by jumping or climbing. To become great jumpers, frogs evolved long hind legs and long ankle bones. They also have a short backbone with only ten vertebrae. Frog and toad skin hangs loosely on the body, and skin texture can be smooth, warty, or folded. Q: Like all tetrapods except birds and mammals, frogs possess a heart with what structure? Choices: - One Chamber - four chambers - eight chambers - three chambers A:
**Answer**
three chambers
Q: Answer the following question given this paragraph: The epidermis is the outer layer of skin. It consists almost entirely of epithelial cells. There are no blood vessels, nerve endings, or glands in this skin layer. Nonetheless, this layer of skin is very active. It is constantly being renewed. How does this happen?. Q: Lacking blood vessels, nerve endings, or glands, the epidermis is the outer layer of what? Choices: - liver - brain - lungs - skin A:
A: skin