Answer:
radiometric dating methods
Explanation:
The oldest rock layer will be at the very bottom, and as time goes on, more layers will form making the top layer the youngest layer and the bottom layer the oldest. This method can determine the amount of radioactive decay of certain elements which can help them make a geologic time scale.
Answer:
Stem cells are currently being used to replace damaged cells or to treat some forms of cancer, usually taken from the adult hip (bone marrow)
The correct answer is - D. A drought kills all the plants in an area, leaving bare land.
If there's such a big drought that will manage to kill off all the vegetation in an area and leave bare land behind it, than the land will be degraded in no time. Once the land is left without its natural protection that the roots of the vegetation provide, the land will be exposed to high rates of and erosion. The erosion will be very quick and the top layers of the soil will be moved away with every wind and rainfall that will appear. That will degrade the land to a very high degree, making it totally unusable and it will need lot of time to eventually recuperate.
They need to create an unique name that would be recognized as belonging to one organism
<u>Answer:</u>
<em>In highly diverged lineages, the substitutions process will occur at sites that have been substituted previously</em>.
<u>Explanation:</u>
Molecular clock uses the mutation rate to reduce the time in prehistory when the life forms are diverged. <em>The molecular clock uses the sequence of amino acids and nucleotide sequence for the DNA.</em>
This clock does not measure any time but the number of mutations, and other changes over certain time. <em>Sometimes its useful property might be limited due to the highly diverged lineages.</em>
