Answer the following question given this paragraph: Q: In earthworms, the skin serves as what type of organ? Choices: - kidney - reproductive - excretory - respiratory A:
respiratory
(Question)
Answer the following question given this paragraph: The trp Operon: A Repressor Operon Bacteria such as E. coli need amino acids to survive. Tryptophan is one such amino acid that E. coli can ingest from the environment. coli can also synthesize tryptophan using enzymes that are encoded by five genes. These five genes are next to each other in what is called the tryptophan (trp) operon (Figure 16.3). If tryptophan is present in the environment, then E. coli does not need to synthesize it and the switch controlling the activation of the genes in the trp operon is switched off. However, when tryptophan availability is low, the switch controlling the operon is turned on, transcription is initiated, the genes are expressed, and tryptophan is synthesized. Q: E. coli need what kind of acids to survive? Choices: - hydrochloric - bacterial - boric - amino A:
(Answer)
amino
Ques: Answer the following question given this paragraph: Chemistry in Everyday Life Transition Metal Catalysts One of the most important applications of transition metals is as industrial catalysts. As you recall from the chapter on kinetics, a catalyst increases the rate of reaction by lowering the activation energy and is regenerated in the catalytic cycle. Over 90% of all manufactured products are made with the aid of one or more catalysts. The ability to bind ligands and change oxidation states makes transition metal catalysts well suited for catalytic applications. Vanadium oxide is used to produce 230,000,000 tons of sulfuric acid worldwide each year, which in turn is used to make everything from fertilizers to cans for food. Plastics are made with the aid of transition metal catalysts, along with detergents, fertilizers, paints, and more (see Figure 19.26). Very complicated pharmaceuticals are manufactured with catalysts that are selective, reacting with one specific bond out of a large number of possibilities. Catalysts allow processes to be more economical and more environmentally friendly. Developing new catalysts and better understanding of existing systems are important areas of current research. Q: What happens if a catalyst runs out? Choices: - variety slows - variety increases - reaction increases - reaction slows A:
Ans: reaction slows
(Q).
Answer the following question given this paragraph: Air quality is a measure of the pollutants in the air. More pollutants mean poorer air quality. Poor air quality started to become a serious problem after the Industrial Revolution. Factories burned coal for energy. Gasoline burned by cars and trucks added greatly to air pollution. By the mid-1900s, air quality in many big cities was very bad. Incidents in London and in U. S. cities alerted people to the extent of the problem. It was clear that air quality needed to be protected. Q: Air quality is a measure of what in the air? Choices: - clouds - gases - water - pollutants A:
(A).
pollutants
Ques:Answer the following question given this paragraph: Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure below ). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. For an animated version of metallic bonding, go to this URL:. Q: What kind of bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them? Choices: - neutron bonds - liquid bonds - ionized bonds - metallic bonds A:

Ans:metallic bonds
Answer the following question given this paragraph: Q: The release of mature eggs that occurs at the midpoint of each cycle is called? Choices: - fertilization - induction - semination - ovulation A:
ovulation