Answer the following question given this paragraph: Two unique features of mollusks are the mantle and radula (see Figure above ). The mantle is a layer of tissue that lies between the shell and the body. It secretes calcium carbonate to form the shell. It forms a cavity, called the mantle cavity, between the mantle and the body. The mantle cavity pumps water for filter feeding. The radula is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. Herbivorous mollusks use the radula to scrape food such as algae off rocks. Predatory mollusks use the radula to drill holes in the shells of their prey. Q: What is a layer of tissue that lies between the shell and the body? Choices: - stem - silt - node - mantle A:
mantle
Answer the following question given this paragraph: Work is defined as the product of a force times the distance over which the force acts. The force and the distance must act along the same line; if the angle between them is not (or ) then you must use the component of force; hence the in the equation. Q: What is defined as the product of a force times the distance over which the force acts? Choices: - matter - motion - energy - work A:
work
Q: Answer the following question given this paragraph: There are other forms of radioactive dating. Rocks, for example, can sometimes be dated based on the decay of 238 U . The decay series for 238 U ends with 206 Pb , so that the ratio of these nuclides in a rock is an indication of how long it has been since the rock solidified. The original composition of the rock, such as the absence of lead, must be known with some confidence. However, as with carbon-14 dating, the technique can be verified by a consistent body of knowledge. Since 238 U has a half-life of solidified about. Q: What is the term for dating a rock based on composition decay? Choices: - carbon dating - fuel dating - safe dating - radioactive dating A:
A: radioactive dating
Question: Answer the following question given this paragraph: How does sap get to the tops of tall trees? (Recall that a column of water can only rise to a height of 10 m when there is a vacuum at the topsee Example 11.5. ) The question has not been completely resolved, but it appears that it is pulled up like a chain held together by cohesive forces. As each molecule of sap enters a leaf and evaporates (a process called transpiration), the entire chain is pulled up a notch. So a negative pressure created by water evaporation must be present to pull the sap up through the xylem vessels. In most situations, fluids can push but can exert only negligible pull, because the cohesive forces seem to be too small to hold the molecules tightly together. But in this case, the cohesive force of water molecules provides a very strong pull. Figure 11.36 shows one device for studying negative pressure. Some experiments have demonstrated that negative pressures sufficient to pull sap to the tops of the tallest trees can be achieved. Q: How does sap get to the tops of tall trees? Choices: - through suction power - via Coriolis forces - through pressure from below - through negative pressure A:
Answer: through negative pressure
*Question*
Answer the following question given this paragraph: Below 200 meters is the aphotic zone. There are no primary producers here because there isn't enough sunlight for photosynthesis. However, the water may be rich in nutrients because of dead organisms drifting down from above. Organisms that live here may include bacteria, sponges, sea anemones, worms, sea stars, and fish. Q: Which zone is located below 200 meters from the surface? Choices: - epipelagic - observable zone - mesopelagic - aphotic zone A:
**Answer**
aphotic zone
Q: Answer the following question given this paragraph: When using the lens makers equation, remember that real things get positive numbers and virtual things get negative numbers. Thus, diverging lenses and virtual images get negative numbers. The object distance is always positive. Q: In the lens makers' equation, diverging lenses and virtual images are associated with what kinds of numbers? Choices: - positive numbers - variable numbers - fractional numbers - negative numbers A:
A: negative numbers