Answer the following question given this paragraph: In the nematic phase, only the long axes of the molecules are parallel, and the ends are staggered at random intervals. In the smectic phase, the long axes of the molecules are parallel, and the molecules are also arranged in planes. Finally, in thecholesteric phase, the molecules are arranged in layers; each layer is rotated with respect to the ones above and below it to give a spiral structure. The molecular order increases from the nematic phase to the smectic phase to the cholesteric phase, and the phases become increasingly opaque. Molecules that form liquid crystals tend to be rigid molecules with polar groups that exhibit relatively strong dipoledipole or dipoleinduced dipole interactions, hydrogen bonds, or some combination of both. Some examples of substances that form liquid crystals are listed in Figure 11.27 "Structures of Typical Molecules That Form Liquid Crystals*" along with their characteristic phase transition temperature ranges. In most cases, the intermolecular interactions are due to the presence of polar or polarizable groups. Aromatic rings and multiple bonds between carbon and nitrogen or oxygen are especially common. Moreover, many liquid crystals are composed of molecules with two similar halves connected by a unit having a multiple bond. Figure 11.27 Structures of Typical Molecules That Form Liquid Crystals*. Q: In the nematic phase, only the long axes of the molecules are parallel, and the ends are staggered at random intervals. in the smectic phase, the long axes of the molecules are parallel, and the molecules are also arranged in planes. finally, in thecholesteric phase, the molecules are arranged in layers; each layer is rotated with respect to the ones above and below it to give it this? Choices: - layer structure - kinetic energy - symmetry - spiral structure A:
spiral structure
(Question)
Answer the following question given this paragraph: Iron is oxidized to Fe2+(aq) at an anodic site on the surface of the iron, which is often an impurity or a lattice defect. Oxygen is reduced to water at a different site on the surface of the iron, which acts as the cathode. Electrons are transferred from the anode to the cathode through the electrically conductive metal. Water is a solvent for the Fe2+ that is produced initially and acts as a salt bridge. Rust (Fe2O3xH2O) is formed by the subsequent oxidation of Fe2+ by atmospheric oxygen. In the corrosion process, iron metal acts as the anode in a galvanic cell and is oxidized to Fe2+; oxygen is reduced to water at the cathode. The relevant reactions are as follows:. Q: Iron is oxidized to fe2+(aq) at an anodic site on the surface of the iron, which is often an impurity or this? Choices: - displacement defect - spontaneous mutation - ladder complex - lattice defect A:
(Answer)
lattice defect
Ques: Answer the following question given this paragraph: Adipose Tissue Adipose tissue produces and secretes several hormones involved in lipid metabolism and storage. One important example is leptin, a protein manufactured by adipose cells that circulates in amounts directly proportional to levels of body fat. Leptin is released in response to food consumption and acts by binding to brain neurons involved in energy intake and expenditure. Binding of leptin produces a feeling of satiety after a meal, thereby reducing appetite. It also appears that the binding of leptin to brain receptors triggers the sympathetic nervous system to regulate bone metabolism, increasing deposition of cortical bone. Adiponectinanother hormone synthesized by adipose cellsappears to reduce cellular insulin resistance and to protect blood vessels from inflammation and atherosclerosis. Its levels are lower in people who are obese, and rise following weight loss. Q: What type of tissue produces and secretes several hormones involved in lipid metabolism and storage? Choices: - hormonal tissue - metabolism tissue - somatic tissue - adipose tissue A:
Ans: adipose tissue
(Q).
Answer the following question given this paragraph: The head of the sperm contains the nucleus. The nucleus holds the chromosomes. In humans, the nucleus of a sperm cell contains 23 chromosomes. The acrosome on the head contains enzymes that help the sperm penetrate an egg. Q: The head of the sperm contains what, which holds the chromosomes? Choices: - nerve cells - fiber - eggs - nucleus A:
(A).
nucleus
Ques:Answer the following question given this paragraph: Rheumatic fever is caused by a virus that has antigens similar to molecules in human heart tissues. When the immune system attacks the virus, it may also attack the heart. What type of immune system disease is rheumatic fever? Explain your answer. Q: Name the fever that is caused by a virus that has antigens similar to molecules in human heart tissues. Choices: - Dengue fever - yellow fever - chronic fever - rheumatic fever A:

Ans:rheumatic fever
Answer the following question given this paragraph: Figure 34.12 (a) Light from a distant galaxy can travel different paths to the Earth because it is bent around an intermediary galaxy by gravity. This produces several images of the more distant galaxy. (b) The images around the central galaxy are produced by gravitational lensing. Each image has the same spectrum and a larger red shift than the intermediary. (credit: NASA, ESA, and STScI). Q: Light from a distant galaxy can travel different paths to the earth because it is bent around an intermediary galaxy by what? Choices: - radiation - strength - variation - gravity A:
gravity