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
(Question)
Answer the following question given this paragraph: Many people think of bones as being dead, dry, and brittle. These adjectives correctly describe the bones of a preserved skeleton, but the bones in a living human being are very much alive. As shown in Figure below , the basic structure of bones is bone matrix , which forms the underlying rigid framework of bones, formed of both compact and spongy bone. The bone matrix consists of tough protein fibersmainly collagenthat become hard and rigid due to mineralization with calcium crystals. Bone matrix is crisscrossed by blood vessels and nerves and also contains specialized bone cells that are actively involved in metabolic processes. Q: The bone matrix consists of tough protein fibersmainly what? Choices: - tissues - hemoglobin - tendons - collagen A:
(Answer)
collagen
Ques: Answer the following question given this paragraph: Sediments are deposited horizontally so sedimentary rock layers are originally horizontal. Q: What direction are sediments deposited? Choices: - magnetic poles - diagonally - vertically - horizontally A:
Ans: horizontally
(Q).
Answer the following question given this paragraph: Which layers of the stem are made of parenchyma cells? a. cortex and pith b. phloem c. sclerenchyma d. xylem Like the rest of the plant, the stem has three tissue systems: dermal, vascular, and ground tissue. Each is distinguished by characteristic cell types that perform specific tasks necessary for the plant's growth and survival. Dermal Tissue The dermal tissue of the stem consists primarily of epidermis, a single layer of cells covering and protecting the underlying tissue. Woody plants have a tough, waterproof outer layer of cork cells commonly known as bark, which further protects the plant from damage. Epidermal cells are the most numerous and least differentiated of the cells in the epidermis. The epidermis of a leaf also contains openings known as stomata, through which the exchange of gases takes place (Figure 30.8). Two cells, known as guard cells, surround each leaf stoma, controlling its opening and closing and thus regulating the uptake of carbon dioxide and the release of oxygen and water vapor. Trichomes are hair-like structures on the epidermal surface. They help to reduce transpiration (the loss of water by aboveground plant parts), increase solar reflectance, and store compounds that defend the leaves against predation by herbivores. Q: Which part of a leaf contains openings known as stomata, through which the exchange of gases takes place? Choices: - stoma - cuticle - phloem - epidermis A:
(A).
epidermis
Ques:Answer the following question given this paragraph: Eventually a main sequence star will use up all of its hydrogen. It then starts to fuse helium atoms into larger elements like carbon. At this time, the star's core will collapse inward. The star's outer layers will spread out and cool. The result is a larger star that is cooler on the surface, and red in color. The star is now a red giant . Q: When a star's core collapses inward while the outer layers spread and cool, what "colorful" celestial body forms? Choices: - blue giant - green giant - white giant - red giant A:

Ans:red giant
Answer the following question given this paragraph: The use of nuclear fusion for energy has several pros. Unlike nuclear fission, which involves dangerous radioactive elements, nuclear fusion involves just hydrogen and helium. These elements are harmless. Hydrogen is also very plentiful. There is a huge amount of hydrogen in ocean water. The hydrogen in just a gallon of water could produce as much energy by nuclear fusion as burning 1,140 liters (300 gallons) of gasoline! The hydrogen in the oceans would generate enough energy to supply all the world's people for a very long time. Q: Hydrogen and helium are specifically involved as reactants in what nuclear reaction that is useful for making energy? Choices: - destructive fusion - radioactive fusion - nuclear fission - nuclear fusion A:
nuclear fusion