Answer the following question given this paragraph: isolating the individual components, preservationists are better able to determine the condition of an object and those books and documents most in need of immediate protection. The simplest class of organic compounds is the hydrocarbons, which consist entirely of carbon and hydrogen. Petroleum and natural gas are complex, naturally occurring mixtures of many different hydrocarbons that furnish raw materials for the chemical industry. The four major classes of hydrocarbons are the alkanes, which contain only carbonhydrogen and carboncarbon single bonds; the alkenes, which contain at least one carboncarbon double bond; the alkynes, which contain at least one carboncarbon triple bond; and the aromatic hydrocarbons, which usually contain rings of six carbon atoms that can be drawn with alternating single and double bonds. Alkanes are also called saturated hydrocarbons, whereas hydrocarbons that contain multiple bonds (alkenes, alkynes, and aromatics) are unsaturated. Q: The simplest class of organic compounds is the what? Choices: - particles - Phenols - gas - hydrocarbons A:
hydrocarbons
(Question)
Answer the following question given this paragraph: Water is the only substance on Earth that is stable in all three states. Q: What is the only substance on earth that is stable in all three states? Choices: - carbon - mercury - air - water A:
(Answer)
water
Ques: Answer the following question given this paragraph: The first organisms were made of only one cell ( Figure below ). The earliest cells were prokaryotes . Prokaryotic cells are surrounded by a cell membrane. They do not have a nucleus. Their organelles are free in the cell. The cells get their nutrients directly from the water they live in. The cells need to use these nutrients to live and grow. Q: The earliest cells were prokaryotes, surrounded by a cell membrane but lacking which key structure? Choices: - mitochondria - ribosomes - lysosomes - nucleus A:
Ans: nucleus
(Q).
Answer the following question given this paragraph: Range shifts are already being observed: for example, some European bird species ranges have moved 91 km northward. The same study suggested that the optimal shift based on warming trends was double that distance, suggesting that the populations are not moving quickly enough. Range shifts have also been observed in plants, butterflies, other insects, freshwater fishes, reptiles, and mammals. Climate gradients will also move up mountains, eventually crowding species higher in altitude and eliminating the habitat for those species adapted to the highest elevations. Some climates will completely disappear. The rate of warming appears to be accelerated in the arctic, which is recognized as a serious threat to polar bear populations that require sea ice to hunt seals during the winter months: seals are the only source of protein available to polar bears. A trend to decreasing sea ice coverage has occurred since observations began in the mid-twentieth century. The rate of decline observed in recent years is far greater than previously predicted by climate models. Finally, global warming will raise ocean levels due to melt water from glaciers and the greater volume of warmer water. Shorelines will be inundated, reducing island size, which will have an effect on some species, and a number of islands will disappear entirely. Additionally, the gradual melting and subsequent refreezing of the poles, glaciers, and higher elevation. Q: Global warming will raise ocean levels due to melt water from glaciers and the greater volume of what? Choices: - greenhouse gases - rainforests - rain - warmer water A:
(A).
warmer water
Ques:Answer the following question given this paragraph: Comparative embryology is the study of the similarities and differences in the embryos of different species. Similarities in embryos are evidence of common ancestry. All vertebrate embryos, for example, have gill slits and tails. Most vertebrates, except for fish, lose their gill slits by adulthood. Some of them also lose their tail. In humans, the tail is reduced to the tail bone. Thus, similarities organisms share as embryos may be gone by adulthood. This is why it is valuable to compare organisms in the embryonic stage. See http://www. pbs. org/wgbh/evolution/library/04/2/pdf/l_042_03. pdf for additional information and a comparative diagram of human, monkey, pig, chicken and salamander embryos. Q: What is the study of the similarities and differences in the embryos of different species? Choices: - example embryology - prenatal biology - diversified embryology - comparative embryology A:

Ans:comparative embryology
Answer the following question given this paragraph: Waterfowl are birds that live on the water. These include ducks, geese, swans, and pelicans, to name a few. Landfowl are ground-feeding birds such as chickens and turkeys. Penguins are a group of flightless birds adapted for life in the water with flippers. Diurnal raptors are birds of prey that hunt during the day. These include falcons, eagles and hawks. Nocturnal raptors hunt during the night. These include various types of owls. Parrots are brightly colored and very intelligent. They are found in the tropics and include cockatoos, parrots, and parakeets. Q: What is the name for birds that live on water like ducks? Choices: - gamefowl - guineafowl - landfowl - waterfowl A:
waterfowl