B. Cell membrane
Remember cell membrane is the structure aka “wall of the house” is the clear boundary between the cells internal and external environments:))
Hope this helps
Nitrogen Fixation. Good luck :)
Answer: Genetic variation within a species can result from a few different sources. Mutations, the changes in the sequences of genes in DNA, are one source of genetic variation. ... As a result, the tree-colored moths are more likely to survive, reproduce, and pass on their genes.
Explanation:
Copernicus' model: "Sun-centered," or "heliocentric"
Copernicus thought that the planets orbited the Sun, and that the Moon orbited Earth. ... Copernicus was correct about some things, but wrong about others. The Sun is not in the center of the universe, and it does move, as do the stars.
The decay of uranium isotopes is used to provide information about the age of Earth.
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Explanation:</h3>
Isotopes of Uranium U-232, U-233 , U-234 , U-235 , U-236 , U-238 are used as fuel in nuclear reactors or as explosives for nuclear weapons. Uranium 238 is not very radioactive and it constitutes for nearly 99.3% of natural uranium on Earth and has the longest lifetime: its period is 4.5 billion years, about the age of Earth.
Use of radiometric dating techniques help in defining the age of substances (natural or man-made) using the known decay rates of radioactive elements. Each element has an individual decay rate and half life time.
Two Uranium isotopes (U-238 and U-235) are used for radiometric dating. Both the isotopes have different decay rates and half life period. Both are unstable and radioactive. Since two different isotopes produce two different decay clocks (one as a reference to other), it is beneficial in accurately determining the age of samples. The age of earth (rocks or other natural elements) can be easily determined using Uranium isotopes.
