Answer the following question given this paragraph: The stoichiometry of a reaction describes the relative amounts of reactants and products in a balanced chemical equation. A stoichiometric quantity of a reactant is the amount necessary to react completely with the other reactant(s). If a quantity of a reactant remains unconsumed after complete reaction has occurred, it is in excess. The reactant that is consumed first and limits the amount of product(s) that can be obtained is the limiting reactant. To identify the limiting reactant, calculate the number of moles of each reactant present and compare this ratio to the mole ratio of the reactants in the balanced chemical equation. The maximum amount of product(s) that can be obtained in a reaction from a given amount of reactant(s) is the theoretical yield of the reaction. The actual yieldis the amount of product(s) actually obtained in the reaction; it cannot exceed the theoretical yield. The percent yield of a reaction is the ratio of the actual yield to the theoretical yield, expressed as a percentage. Q: If a quantity of a reactant remains unconsumed after complete reaction has occurred, it is? Choices: - reduced - static - missing - in excess A:
in excess
Answer the following question given this paragraph: Many cancerous cells are the products of normal cells that have lost the ability to regulate the cell cycle. The genes that encode the proteins involved in cell cycle regulation have mutations. One category of genes, called oncogenes, accelerate the cell cycle. Some cancers can be inherited, such as breast cancer (due to mutations in the BRCA1 and BRCA2 genes). Approximately five to ten percent of cancers are entirely hereditary. Other cancers are triggered by an environmental stimulus, such as through the relationship between tobacco smoke and lung cancer, or ultraviolet radiation and skin cancer. Q: What type of cells are often the product of normal cells that have lost the ability to regulate the cell cycle? Choices: - corrosive cells - uncontrolled cells - sick cells - cancerous cells A:
cancerous cells
Q: Answer the following question given this paragraph: The release of calcium ions initiates muscle contractions. Watch this video (http://openstaxcollege. org/l/calciumrole) to learn more about the role of calcium. (a) What are "T-tubules" and what is their role? (b) Please describe how actinbinding sites are made available for cross-bridging with myosin heads during contraction. Q: The release of calcium ions initiates what? Choices: - exhalation - cramps - spasms - muscle contractions A:
A: muscle contractions
Question: Answer the following question given this paragraph: How fast a chemical reaction occurs is called the reaction rate . Several factors affect the rate of a given chemical reaction. They include the:. Q: What term is used to describe how fast a chemical reaction occurs? Choices: - response time - catalysis - velocity - reaction rate A:
Answer: reaction rate
*Question*
Answer the following question given this paragraph: Most prokaryotes get both energy and carbon from other living things. Many of them are decomposers. They break down wastes and remains of dead organisms. In this way, they help to recycle carbon and nitrogen through ecosystems. Q: By breaking down wastes and remains of dead organisms, decomposers perform what function in an ecosystem? Choices: - reproduction - symbiosis - collecting - recycling A:
**Answer**
recycling
(Q).
Answer the following question given this paragraph: Autoimmunity can develop with time, and its causes may be rooted in molecular mimicry. Antibodies and TCRs may bind self antigens that are structurally similar to pathogen antigens, which the immune receptors first raised. As an example, infection with Streptococcus pyogenes (bacterium that causes strep throat) may generate antibodies or T cells that react with heart muscle, which has a similar structure to the surface of S. pyogenes. These antibodies can damage heart muscle with autoimmune attacks, leading to rheumatic fever. Insulin-dependent (Type 1) diabetes mellitus arises from a destructive inflammatory TH1 response against insulin-producing cells of the pancreas. Patients with this autoimmunity must be injected with insulin that originates from other sources. Q: Autoimmunity can develop with time, and its causes may be rooted in this? Choices: - inheritance - resistance - spontaneous mutation - molecular mimicry A:
(A).
molecular mimicry