Answer:
The fossils in the lower layers are older than the fossils in the upper layers.
Explanation:
I think it is b because it is a result of an environmental influence
Answer:
If a DNA molecule has 30% Adenine the percentage of the other bases is Thymine: 30% Cytosine: 20% Guanine: 20%.
Explanation:
When the percentage that a base has in a DNA molecule is given, the percentage of the other bases can be known using the Chargaff's base pair rule.
A DNA molecule has the information of the genome of a living being, according to a specific sequence of its nitrogenous bases adenine, guanine, cytosine and thymine.
Chargaff was able to establish that in a DNA molecule the ratio of purine : pyrimidine of 1:1, so there must be the same amount of thymine as adenine and a similar amount of guanine for the cytosine, taking into account the complementarity of bases.
Taking into account the law of the base pair, if in a DNA chain there is 30% of Adenine, in the molecule there is:
- <em>Adenine 30%.
</em>
- <em>Thymine 30%.
</em>
- <em>Cytosine 20%.
</em>
- <em>Guanine 20%.
</em>
- <em>Total ..... 100%
</em>
In this case, the <u>Chargaff rule is useful to determine the percentage of nitrogenous bases that exist in a DNA molecule, knowing the percentage of a single base</u>.
Instead of burning coal to power our country we could use solar panels. As long as we have the sun we will have "free" energy.
Instead of continuing to mine for metals, we could recycle metals and then less greenhouse gases would be released into Earth's atmosphere.
A fossil would from through mineral replacement by replacing the existing material of the animals bones with minerals, to become petrified. The Minerals will keep the fossil preserved longer.
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