Answer the following question given this paragraph: How Hormones Work Hormones cause changes in target cells by binding to specific cell-surface or intracellular hormone receptors, molecules embedded in the cell membrane or floating in the cytoplasm with a binding site that matches a binding site on the hormone molecule. In this way, even though hormones circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors. Receptors for a specific hormone may be found on or in many different cells or may be limited to a small number of specialized cells. For example, thyroid hormones act on many different tissue types, stimulating metabolic activity throughout the body. Cells can have many receptors for the. Q: Although what biochemicals circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors? Choices: - Cells - organs - enzymes - hormones A:
hormones
Answer the following question given this paragraph: Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adult's body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form, and the life cycle repeats. Q: Flatworms reproduce sexually. in most species, the same individuals produce both what? Choices: - gametes - heart and sperm - diploid and haploid - eggs and sperm A:
eggs and sperm
Q: Answer the following question given this paragraph: Lipids are organic compounds that consist of carbon, hydrogen, and oxygen. They are made up of fatty acids and other compounds. They provide cells with energy, store energy, and help form cell membranes. Q: Lipids are organic compounds that consist of carbon, hydrogen, and? Choices: - nitrogen - methane - helium - oxygen A:
A: oxygen
Question: Answer the following question given this paragraph: Differences in density between water and air lead to differences in pressure. Q: Differences in density between water and air lead to differences in what? Choices: - resistance - sound - energy - pressure A:
Answer: pressure
*Question*
Answer the following question given this paragraph: polar, while others are strongly polar. Ionic bonds can be considered the ultimate in polarity, with electrons being transferred rather than shared. To judge the relative polarity of a covalent bond, chemists use electronegativity, which is a relative measure of how strongly an atom attracts electrons when it forms a covalent bond. There are various numerical scales for rating electronegativity. Figure 4.4 "Electronegativities of Various Elements" shows one of the most popularthe Pauling scale. The polarity of a covalent bond can be judged by determining the difference in the electronegativities of the two atoms making the bond. The greater the difference in electronegativities, the greater the imbalance of electron sharing in the bond. Although there are no hard and fast rules, the general rule is if the difference in electronegativities is less than about 0.4, the bond is considered nonpolar; if the difference is greater than 0.4, the bond is considered polar. If the difference in electronegativities is large enough (generally greater than about 1.8), the resulting compound is considered ionic rather than covalent. An electronegativity difference of zero, of course, indicates a nonpolar covalent bond. Q: What kind of bonds, where electrons are transferred rather than shared, are considered the ultimate in polarity? Choices: - covalent bonds - soluble bonds - magnetic bonds - ionic bonds A:
**Answer**
ionic bonds
Q: Answer the following question given this paragraph: Skeletal Muscle Fiber Structure Each skeletal muscle fiber is a skeletal muscle cell. These cells are incredibly large, with diameters of up to 100 m and lengths of up to 30 cm. The plasma membrane of a skeletal muscle fiber is called the sarcolemma. The sarcolemma is the site of action potential conduction, which triggers muscle contraction. Within each muscle fiber are myofibrilslong cylindrical structures that lie parallel to the muscle fiber. Myofibrils run the entire length of the muscle fiber, and because they are only approximately 1.2 m in diameter, hundreds to thousands can be found inside one muscle fiber. They attach to the sarcolemma at their ends, so that as myofibrils shorten, the entire muscle cell contracts (Figure 38.34). Q: The plasma membrane of a skeletal muscle fiber is called the what? Choices: - sheath - annulata - soleus - sarcolemma A:
A: sarcolemma