If a single <span>mutation turns off the growth of some pairs of legs within an organism a hox gene will most likely be affected. so the answe is (b)
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<span>Embryonic tissues or germ layers develop during the gastrulation stage.</span> <span>Gastrulation is a process in embryonic development during which the single-layered blastula is reorganized into a three-layered(or two-layered) structure called the gastrula. <span>Two primary germ layers(embryonic tissues) are an inner layer-endoderm and an outer layer-ectoderm. Endoderm and ectoderm interact and produce a third layer-mesoderm. Gastrulation is followed by organogenesis, three germ layers will give rise to specific tissue and organ.For example, ectoderm gives rise to epidermis and nervous system, endoderm to the digestive system and mesoderm to muscles, bones…</span></span>
Answer:
The correct answers are A, B and D. The Clean Air Act was important because it emphasized cost-effective methods to protect the air; encouraged people to study the effects of dirty air on human health; and created a regulation that makes any activities that pollute the air illegal.
Explanation:
The Clean Air Act is a federal federal law designed to control air pollution nationwide. The Environmental Protection Agency (EPA) is required to develop and enforce the regulations to protect the general public from exposure to air pollutants that are known to be dangerous to human health. The 1963 law established a basic research program, which was expanded in 1967. The main changes to the law, which require regulatory controls of air pollution, were promulgated in 1970, 1977 and 1990.
The 1970 amendments significantly expanded the federal mandate by demanding broad federal and state regulations, both for fixed sources of pollution (industrial) and mobile sources.
In 1990 provisions were added to deal with acid rain, depletion of the ozone layer and toxic air pollution, and a program of national permits of fixed sources was established. Also new requirements were established for the reformulation of gasoline, the adjustment of Reid vapor pressure (RVP), which measures the volatility of gasoline; and the norms to control the evaporation emissions of the gasoline.
The Clean Air Act is important because it was the first important environmental law in the United States to include a disposition regarding citizen demands. Numerous local and state governments have promulgated similar laws, either the execution of federal programs or to fill important loopholes at the local level in federal programs.
There are some insects that can walk on water, this phenomenon is possible because the water has surface tension. One animal that can walk on water is the lizard.
