Answer the following question given this paragraph: Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements. They often combine with group 17 elements, which are very "eager" to gain an electron. At the URL below, you can watch a video that shows just how reactive the alkali metals are. Q: Because alkali metals are so reactive, they are found in nature only in ________ with other elements? Choices: - isolation - cooperation - competition - combination A:
combination
Answer the following question given this paragraph: Q: Corals build hard exoskeletons that grow to become what? Choices: - algae - stability reefs - fungi - coral reefs A:
coral reefs
Q: Answer the following question given this paragraph: Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors. A vector is any measurement that has both size and direction. People commonly think of acceleration as in increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative and called deceleration. A change in direction without a change in speed is acceleration as well. Q: What is the term for the rate at which velocity changes? Choices: - stability - transmission - compression - acceleration A:
A: acceleration
Question: Answer the following question given this paragraph: organelle in muscle fibers that allows muscles to contract. Q: What term is used to describe muscle fibers that allows muscles to contract? Choices: - organisms - fluorescence - ligaments - organelle A:
Answer: organelle
*Question*
Answer the following question given this paragraph: Tight junctions are common at epithelia, which are sheets of cells that form a boundary between a mass of cells and a cavity or space (a lumen ). The membranes of these cells join together, forming a virtually impermeable barrier to fluid. Tight junctions essentially seal adjacent epithelial cells in a narrow layer just beneath their apical surface, which is the portion of the cell exposed to the lumen. The rest of the cell surface is known as the basolateral surface. Tight junctions prevent integral membrane proteins from moving between the apical and basolateral surface, maintaining the properties of those distinct surfaces. For example, receptor-mediated endocytosis occurs at the apical surface and exocytosis at the basolateral surface. Q: What is the term for sheets of cells that form a boundary between a mass of cells and a cavity or space? Choices: - mucus - myelin - ganglion - epithelia A:
**Answer**
epithelia
Answer the following question given this paragraph: Q: Rapidly produced genetic vairants are found in organisms with what type of generation time? Choices: - long - repeating - oscillating - short A:
short