The correct answer is D. Salt water.
Explanation
The hydrosphere is the system that groups all the waters of the earth that include oceans, seas, rivers, lakes, lagoons, frozen waters like ice and snow, among others. The water of the earth can be classified between salt water and freshwater, within the first group we find the oceans and the seas that represent two thirds of the total water of the earth, that is, 93 percent of the total water of the earth, a figure close to 1 370 323 000km³; the rest of the water is fresh and consists of rivers, lakes, lagoons, streams, groundwater, and glaciers. So, the correct answer is D. Salt water
Nematodes are wormlike organisms which can be seen with naked eye, live in water-filled pore spaces in the soil. Nematodes are in large number in the upper soil layers where organic matter, plant roots, and other resources are most abundant.
The functions of nematodes:
- Free-living nematodes decompose organic material into nutrients and cycled them in the soil by feeding on some bacteria and fungi.
- Nematodes help in distributing bacteria and fungi through the soil and along roots by carrying live and dormant microbes.
- They used as food for higher predators, soil microorthropodes.
- They eat disease-causing organisms, thus suppress their growth.
- They acts as potential bio- control agents.
The Griffith's experiment, the Avery-MacLeod-McCarty experiment, and the Hershey–Chase experiments were the set of experiments that established DNA as the key hereditary molecule. The Avery-MacLeod-McCarty experiment was an extension to the Griffith's experiment. The heat killed virulent S strain cells of the Griffith's experiment were lysed to form a supernatant containing a mix of RNA, DNA, proteins and lipids from the cell. The supernatent was equally divided into 3 parts after the removal of the lipids. The 3 parts were respectively treated with an RNAase to degrade the RNA, DNAase to degrade the DNA and proteinase to degrade the proteins. The treated supernatant was then added into the culture containing the non-virulent R cells. In case of the supernatant treated with the DNAse, no transformation of R cells into S cells occurred. The transformation of R cells to S cells occurred in the proteinase and the RNAse cases. This indicated that DNA was the hereditary molecule and not protein or RNA.
A mutation is a change in a gene
<span>The correct option is C. On Earth's surface directly above the earthquake's focus.
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<span>The hypocenter, or focus is the point where the earthquake really starts. It's located under the surface in the tectonic plate boundary. </span><span> <span> <span> </span> </span> </span>
The epicenter is the point on the surface of the earth that's directly above the hypocenter.
