Q: What structures formed of twisted actin chains are found in almost every cell, and are numerous in muscle cells and cells that move by changing shape? Read this paragraph and choose the correct option from the provided answers: Microfilaments , shown in Figure below (b) , 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 extensions, 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). Choices: - RNA - DNA - vesicles - microfilaments A:
microfilaments

Q: What happens when a sodium atom loses an electron? Read this paragraph and choose the correct option from the provided answers: By losing an electron, the sodium atom becomes a sodium ion. It now has one less electron than protons, giving it a charge of +1. Positive ions such as sodium are given the same name as the element. The chemical symbol has a plus sign to distinguish the ion from an atom of the element. The symbol for a sodium ion is Na + . Choices: - becomes calcium - gains a proton - combines with hydrogen - becomes sodium ion A:
becomes sodium ion

Q: Q: Vesicular transport includes exocytosis and what? Read this paragraph and choose the correct option from the provided answers: There are four main ways that molecules can pass through a phospholipid membrane. The first way requires no energy input by the cell and is called simple diffusion. This type of transport includes passive diffusion and osmosis. No assistance by a transport is necessary in simple diffusion. Facilitated diffusion, does involve the assistance of transport proteins. The third way, called active transport , requires that the cell uses energy to pull in or pump out certain molecules and ions. Active transport involves proteins known as pumps. The fourth way is through vesicle transport , in which large molecules are moved across the membrane in bubble-like sacks that are made from pieces of the membrane. Vesicular transport includes exocytosis and endocytosis. Choices: - phagocytosis - metastasis - meiosis - endocytosis A:
A: endocytosis

Question: Q: If a fixed amount of gas maintains a perfectly inversely proportional relationship between volume and pressure, then what else must be constant about the gas? Read this paragraph and choose the correct option from the provided answers: For a fixed amount of gas at constant temperature, the volume is inversely proportional to its pressure. Choices: - density - friction - surface tension - temperature A:
Answer: temperature

*Question*
Q: Which type of electrons plays the most important role in chemical reactions? Read this paragraph and choose the correct option from the provided answers: Electron Configurations and the Periodic Table As described earlier, the periodic table arranges atoms based on increasing atomic number so that elements with the same chemical properties recur periodically. When their electron configurations are added to the table (Figure 6.30), we also see a periodic recurrence of similar electron configurations in the outer shells of these elements. Because they are in the outer shells of an atom, valence electrons play the most important role in chemical reactions. The outer electrons have the highest energy of the electrons in an atom and are most easily lost or shared than the core electrons. Valence electrons are also the determining factor in some physical properties of the elements. Elements in any one group (or column) have the same number of valence electrons; the alkali metals lithium and sodium each have only one valence electron, the alkaline earth metals beryllium and magnesium each have two, and the halogens fluorine and chlorine each have seven valence electrons. The similarity in chemical properties among. Choices: - noncovalent - intermediate - transition - valence A:
**Answer**
valence

Q: What kind of phenotype results in a case of incomplete dominance? Read this paragraph and choose the correct option from the provided answers: 1. Define energy, and state where living things get the energy they need. Choices: - short phenotype - backward phenotype - long phenotype - intermediate phenotype A:
intermediate phenotype