Answer:
A DNA marker
Explanation:
also known as a size standard or a DNA ladder) is loaded into the first well of the gel. The fragments in the marker are of a known length so can be used to help approximate the size of the fragments in the samples.
When a scientist say's organisms have the same universal genetic code it mainly means that the
"organisms use the same four nucleotide bases." Now <span>organic molecules that serve as the monomer units for forming the nucleic acid polymers.
Hope this helps!
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- keystone species is the correct answer.
<u>keystone species</u> which keeps the number of other animal population in
control and low in the entire ecosystem. They play an important role
through this process and helps the food chain effectively.
dominant species - most common species; found often in the ecosystem.
invasive species - which fights for itself survival and can cause harm to
ecosystem. non-native to an ecosystem