Answer the following question given this paragraph: As an example, even though sodium ions (Na+) are highly concentrated outside of cells, these electrolytes are charged and cannot pass through the nonpolar lipid bilayer of the membrane. Their diffusion is facilitated by membrane proteins that form sodium channels (or "pores"), so that Na+ ions can move down their concentration gradient from outside the cells to inside the cells. There are many other solutes that must undergo facilitated diffusion to move into a cell, such as amino acids, or to move out of a cell, such as wastes. Because facilitated diffusion is a passive process, it does not require energy expenditure by the cell. Water also can move freely across the cell membrane of all cells, either through protein channels or by slipping between the lipid tails of the membrane itself. Osmosis is the diffusion of water through a semipermeable membrane (Figure 3.7). Q: What can sodium ions not pass through? Choices: - Lipid Control - benthic lipid bilayer - narrowness lipid bilayer - nonpolar lipid bilayer A:
nonpolar lipid bilayer
Answer the following question given this paragraph: The two ribosomal subunits are named base on their sedmentation rate in a centrifuge. The unit of measurement is the Svedberg unit , a measure of the rate of sedimentation, not the size. This accounts for why fragment names do not add up (70S is made of 50S and 30S). Q: The svedberg unit is a measure of the rate of what, which is tested in a centrifuge? Choices: - precipitation - temperature - secretion - sedimentation A:
sedimentation
Q: Answer the following question given this paragraph: Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters . Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure below . It runs parallel to the coast like a barrier island. Q: What kind of islands provide natural protection to shorelines? Choices: - patch islands - locational islands - edge islands - barrier islands A:
A: barrier islands
Question: Answer the following question given this paragraph: Q: What's the process responsible for the presence of oxygen in our atmosphere? Choices: - respiration - ozone - glycolysis - photosynthesis A:
Answer: photosynthesis
*Question*
Answer the following question given this paragraph: Nutrients are substances that the body needs for energy, building materials, and control of body processes. Carbohydrates, proteins, lipids, and water are nutrients needed in relatively large amounts. Vitamins and minerals are nutrients needed in much smaller amounts. Q: What are substances that the body needs for energy, building materials, and control of body processes? Choices: - molecules - carbons - acids - nutrients A:
**Answer**
nutrients
*Question*
Answer the following question given this paragraph: You generally can't see, smell, taste, hear, or feel radiation. Fortunately, there are devices such as Geiger counters that can detect radiation. A Geiger counter, like the one pictured in the Figure below , contains atoms of a gas that is ionized if it encounters radiation. When this happens, the gas atoms change to ions that can carry an electric current. The current causes the Geiger counter to click. The faster the clicks occur, the higher the level of radiation. You can see a video about the Geiger counter and how it was invented at the URL below. Q: What does the geiger counter detect? Choices: - vibration - convection - moisture - radiation A:
**Answer**
radiation