Hey pizzalover! The answer from this question would be
a. oxygen
Hope it helps
<span> A </span>test cross<span>, involves the breeding of an individual with a phenotypically recessive individual.
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Answer and Explanation: So the plant/algae take nitrogen from the topsoil by captivating through roots, such as the Glutaminic Acids, ammonium ions, or nitrate ions. Plants can't necessarily get nitrogen from instant air, however, plants obtain nitrogen through a natural process.
Hope this helps! :-)
One solution have a nice day please
