Answer the following question given this paragraph: Graphite is a form of carbon in which carbon atoms are arranged in layers. Bonds are strong between carbon atoms within each layer but relatively weak between atoms in different layers. The weak bonds between layers allow the layers to slide over one another. This makes graphite relatively soft and slippery. It is used as a lubricant. It also makes up the "lead" in pencils. Q: What layered form of carbon is used as a lubricant and in pencils? Choices: - carbonite - copper - lead - graphite A:
graphite
(Question)
Answer the following question given this paragraph: Osmosis and Osmotic Pressure of Solutions A number of natural and synthetic materials exhibit selective permeation, meaning that only molecules or ions of a certain size, shape, polarity, charge, and so forth, are capable of passing through (permeating) the material. Biological cell membranes provide elegant examples of selective permeation in nature, while dialysis tubing used to remove metabolic wastes from blood is a more simplistic technological example. Regardless of how they may be fabricated, these materials are generally referred to as semipermeable membranes. Consider the apparatus illustrated in Figure 11.25, in which samples of pure solvent and a solution are separated by a membrane that only solvent molecules may permeate. Solvent molecules will diffuse across the membrane in both directions. Since the concentration of solvent is greater in the pure solvent than the solution, these molecules will diffuse from the solvent side of the membrane to the solution side at a faster rate than they will in the reverse direction. The result is a net transfer of solvent molecules from the pure solvent to the solution. Diffusion-driven transfer of solvent molecules through a semipermeable membrane is a process known as osmosis. Q: What term means that only molecules or ions of a certain size, shape, polarity or charge are capable of passing through the material? Choices: - classic permeation - induced permeation - radiation permeation - selective permeation A:
(Answer)
selective permeation
Ques: Answer the following question given this paragraph: How do lungs allow air in? Air moves into and out of the lungs by the movement of muscles. The most important muscle in the process of breathing is the diaphragm , a sheet of muscle that spreads across the bottom of the rib cage. The diaphragm and rib muscles contract and relax to move air into and out of the lungs. During inhalation, the diaphragm contracts and moves downward. The rib muscles contract and cause the ribs to move outward. This causes the chest volume to increase. Because the chest volume is larger, the air pressure inside the lungs is lower than the air pressure outside. This difference in air pressures causes air to be sucked into the lungs. When the diaphragm and rib muscles relax, air is pushed out of the lungs. Exhalation is similar to letting the air out of a balloon. Q: What is the most important muscle involved in the process of breathing? Choices: - mouth - chest - trachea - diaphragm A:
Ans: diaphragm
(Q).
Answer the following question given this paragraph: Human organs are organized into organ systems. An organ system is a group of organs that work together to carry out a complex function. Each organ of the system does part of the overall job. For example, the heart is an organ in the circulatory system. The circulatory system also includes the blood vessels and blood. There are many different human organ systems. Figure below shows six of them and gives their functions. Q: The heart is an organ in which system? Choices: - nervous system - immune system - respiratory system - circulatory system A:
(A).
circulatory system
Ques:Answer the following question given this paragraph: Q: How many pairs of autosomes are there? Choices: - five - four - Seven - three A:

Ans:three
Ques:Answer the following question given this paragraph: The digestion of carbohydrates begins in the mouth as -amylase breaks glycosidic linkages in carbohydrate molecules. Essentially no carbohydrate digestion occurs in the stomach, and food particles pass through to the small intestine, where -amylase and intestinal enzymes convert complex carbohydrate molecules (starches) to monosaccharides. The monosaccharides then pass through the lining of the small intestine and into the bloodstream for transport to all body cells. Protein digestion begins in the stomach as pepsinogen in gastric juice is converted to pepsin, the enzyme that hydrolyzes peptide bonds. The partially digested protein then passes to the small intestine, where the remainder of protein digestion takes place through the action of several enzymes. The resulting amino acids cross the intestinal wall into the blood and are carried to the liver. Lipid digestion begins in the small intestine. Bile salts emulsify the lipid molecules, and then lipases hydrolyze them to fatty acids and monoglycerides. The hydrolysis products pass through the intestine and are repackaged for transport in the bloodstream. In cells that are operating aerobically, acetyl-CoA produced in stage II of catabolism is oxidized to carbon dioxide. The citric acid cycle describes this oxidation, which takes place with the formation of the coenzymes reduced nicotinamide adenine dinucleotide (NADH) and reduced flavin adenine dinucleotide (FADH2). The sequence of reactions needed to oxidize these coenzymes and transfer the resulting electrons to oxygen is called the electron transport chain, or the respiratory chain. The compounds responsible for this series of oxidation-reduction reactions include proteins known ascytochromes, FeS proteins, and other molecules that ultimately result in the reduction of molecular oxygen to water. Every time a compound with two carbon atoms is oxidized in the citric acid cycle, a respiratory chain compound accepts the electrons lost in the oxidation (and so is reduced) and then passes them on to the... Q: Protein digestion begins in the stomach as pepsinogen in gastric juice is converted to pepsin, the enzyme that hydrolyzes this? Choices: - disulfide bridges - hydrogen bonds - ionic bonds - peptide bonds A:

Ans:
peptide bonds