Answer the following question given this paragraph: Microfilaments , shown as (b) in Figure below , are made of two thin actin chains that are twisted around one another. Microfilaments are mostly concentrated just beneath the cell membrane, where they support the cell and help the cell keep its shape. Microfilaments form cytoplasmatic extentions, such as pseudopodia and microvilli , which allow certain cells to move. The actin of the microfilaments interacts with the protein myosin to cause contraction in muscle cells. Microfilaments are found in almost every cell, and are numerous in muscle cells and in cells that move by changing shape, such as phagocytes (white blood cells that search the body for bacteria and other invaders). Q: Microfilaments are mostly concentrated just beneath what? Choices: - the nucleus - the cell wall - the cytoplasm - the cell membrane A:
the cell membrane
(Question)
Answer the following question given this paragraph: 39.2 Gas Exchange across Respiratory Surfaces The lungs can hold a large volume of air, but they are not usually filled to maximal capacity. Lung volume measurements include tidal volume, expiratory reserve volume, inspiratory reserve volume, and residual volume. The sum of these equals the total lung capacity. Gas movement into or out of the lungs is dependent on the pressure of the gas. Air is a mixture of gases; therefore, the partial pressure of each gas can be calculated to determine how the gas will flow in the lung. The difference between the partial pressure of the gas in the air drives oxygen into the tissues and carbon dioxide out of the body. Q: Tidal volume, expiratory reserve volume, inspiratory reserve volume, and residual volume are all types of what kind of measurement? Choices: - respiratory volume - emitted volume - breathing volume - lung volume A:
(Answer)
lung volume
Ques: Answer the following question given this paragraph: Q: Similarity that results from common ancestry is known as what? Choices: - affinity - heterogeny - duality - homology A:
Ans: homology
(Q).
Answer the following question given this paragraph: Half-Life Why use a term like half-life rather than lifetime? The answer can be found by examining Figure 31.21, which shows how the number of radioactive nuclei in a sample decreases with time. The time in which half of the original number of nuclei decay is defined as the half-life, t 1 / 2 . Half of the remaining nuclei decay in the next half-life. Further, half of that amount decays in the following half-life. Therefore, the number of radioactive nuclei decreases from. Q: What term means the time in which half of the original number of radioactive nuclei in a sample decay? Choices: - reduced life - quarter-life - partial-life - half-life A:
(A).
half-life
Ques:Answer the following question given this paragraph: Sublimation occurs when ice and snow change directly to water vapor. This also happens because of heat from the sun. Q: When does sublimation occur? Choices: - when the wind changes direction - when the snow melts the ice caps - when the ice and sand change directly into water vapors - when the ice and snow change directly into water vapors A:

Ans:when the ice and snow change directly into water vapors
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