Most hydroelectric power plants have a dam and a reservoir. These structures may obstruct fish migration and affect their populations. Operating a hydroelectric power plant may also change the water temperature and the river's flow. These changes may harm native plants and animals in the river and on land. Reservoirs may cover people's homes, important natural areas, agricultural land, and archaeological sites. So building dams can require relocating people. Methane, a strong greenhouse gas, may also form in some reservoirs and be emitted to the atmosphere. Reservoir construction is "drying up" in the United States Gosh, hydroelectric power sounds great -- so why don't we use it to produce all of our power? Mainly because you need lots of water and a lot of land where you can build a dam and reservoir, which all takes a LOT of money, time, and construction. In fact, most of the good spots to locate hydro plants have already been taken. In the early part of the century hydroelectric plants supplied a bit less than one-half of the nation's power, but the number is down to about 10 percent today. The trend for the future will probably be to build small-scale hydro plants that can generate electricity for a single community. As this chart shows, the construction of surface reservoirs has slowed considerably in recent years. In the middle of the 20th Century, when urbanization was occurring at a rapid rate, many reservoirs were constructed to serve peoples' rising demand for water and power. Since Hydroelectric energy is produced by the force of falling water. The capacity to produce this energy is dependent on both the available flow and the height from which it falls. Building up behind a high dam, water accumulates potential energy. This is transformed into mechanical energy when the water rushes down the sluice and strikes the rotary blades of turbine. The turbine's rotation spins electromagnets which generate current in stationary coils of wire. Finally, the current is put through a transformer where the voltage is increased for long distance transmission over power lines.
Hydroelectric-power production in the United States and the world!
(sorry this is the second part)
Answer:
With respect to the differences in the DNA sequence of six species, including the human one, it is true that the DNA sequences may vary but the aminoacid sequences are identical.
Explanation:
Options for this question:
- <em>The DNA sequences may vary but the amino acid sequences are identical.
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The nitrogen bases in the nucleotides must also be different in each.
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The process in producing additional DNA, replication, is identical in all six.
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The process of producing DNA, or replication, varies due to the differences in the DNA codes.
The different species that exist have specific genomes for each of them, this is the <u>genetic information contained in the DNA varies from one species to another</u>, as can be seen in the scheme (see image). However, the genetic code is universal, and does not vary from one species to another.
The genetic code is found in the RNA molecule and is a sequence of nucleotides that, organized in triplets (codons), are responsible for the synthesis of specific amino acids. An RNA molecule contains the information necessary for protein synthesis.
The scheme shows the differences of five species with respect to the human, based on the respective DNA sequences. But what it does not show is a universally accepted truth, that the nucleotide sequence encoding an amino acid is the same for each of these species.
Learn more:
Genetic code brainly.com/question/15338
Disruptive selection describes changes in population genetics in which extreme values for a trait are favored over intermediate values.
convergent evolution - called analogy
a potential source of confusion in constructing a phylogeny is similarity between organisms that is due to convergent evolution - called analogy - rather than to shared ancestry. thus for mammals, the backbone is a shared ancestral character, a character that originated in an ancestor of the taxon
