Answer the following question given this paragraph: Let's briefly review the basics of covalent bonding as they pertain to carbon. Carbon has four valence electrons, which have a 2s 2 2p 2 configuration in isolated carbon atoms. These four electrons allow carbon to form four covalent bonds, which can mean four single bonds or some combination of single, double, and triple bonds. Q: How many valence electrons can be found in a carbon atom? Choices: - five - three - One - four A:
four
(Question)
Answer the following question given this paragraph: Mammals generate heat mainly by maintaining a high rate of metabolism. Compared with the cells of other animals, the cells of mammals have more mitochondria. Mitochondria are the cell organelles that generate energy. Mammals may also produce little bursts of heat by shivering. Shivering occurs when many muscles all contract slightly at the same time. The muscle contractions generate a small amount of heat. Q: How do mammals generate heat? Choices: - running around fast - eating spicy foods - maintaning low metabolism - maintaining high metabolism A:
(Answer)
maintaining high metabolism
Ques: Answer the following question given this paragraph: The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound . Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound . Ultrasound is too high-pitched for humans to hear. Q: The frequency of sound waves is measured in what unit? Choices: - watt - rads - decibel - hertz A:
Ans: hertz
(Q).
Answer the following question given this paragraph: Symbiosis is a close relationship between two species in which at least one species benefits. Mutualism is a symbiotic relationship in which both species benefit. Commensalism is a symbiotic relationship in which one species benefits while the other species is not affected. Parasitism is a symbiotic relationship in which one species (the parasite) benefits while the other species (the host) is harmed. Q: What type of interspecies relationship involves one party being actively harmed? Choices: - mosaicism - symbiosis - mutualism - parasitism A:
(A).
parasitism
Ques:Answer the following question given this paragraph: London interactions c. London dispersion forces Hydrophilic and Hydrophobic Solutes A solute can be classified as hydrophilic (literally, "water loving"), meaning that it has an electrostatic attraction to water, or hydrophobic ("water fearing"), meaning that it repels water. A hydrophilic substance is polar and often contains OH or NH groups that can form hydrogen bonds to water. For example, glucose with its five OH groups is hydrophilic. In contrast, a hydrophobic substance may be polar but usually contains CH bonds that do not interact favorably with water, as is the case with naphthalene and n-octane. Hydrophilic substances tend to be very soluble in water and other strongly polar solvents, whereas hydrophobic substances are essentially insoluble in water and soluble in nonpolar solvents such as benzene and cyclohexane. The difference between hydrophilic and hydrophobic substances has substantial consequences in biological systems. For example, vitamins can be classified as eitherfat soluble or water soluble. Fatsoluble vitamins, such as vitamin A, are mostly nonpolar, hydrophobic molecules. As a result, they tend to be absorbed into fatty tissues and stored there. In contrast, water-soluble vitamins, such as vitamin C, are polar, hydrophilic molecules that circulate in the blood and intracellular fluids, which are primarily aqueous. Water-soluble vitamins are therefore excreted much more rapidly from the body and must be replenished in our daily diet. A comparison of the chemical structures of vitamin A and vitamin C quickly reveals why one is hydrophobic and the other hydrophilic. Q: What term is used to describe a solute that is water fearing? Choices: - claustrophobic - anti-hydral - hydrogenic - hydrophobic A:

Ans:hydrophobic
Ques: Answer the following question given this paragraph: called growth factors signal some cells at the edge of the ectoderm to become epidermis cells. The remaining cells in the center form the neural plate. If the signaling by growth factors were disrupted, then the entire ectoderm would differentiate into neural tissue. The neural plate undergoes a series of cell movements where it rolls up and forms a tube called the neural tube, as illustrated in Figure 43.28. In further development, the neural tube will give rise to the brain and the spinal cord. Q: The neural plate undergoes a series of cell movements where it rolls up and forms a tube called what? Choices: - cell tube - occular tube - peripheral tube - neural tube A:
Ans:
neural tube