Answer: genetic engineering
Explanation
Genetic engineering is the modification of an organism's phenotype by manipulating its genetic material. Some genetic engineering uses the principle of recombination. Recombination is the process through which a new gene is inserted into a bacterial DNA "The plasmid".
Answer:
Yes, your answer, nitrogen, is correct (the most appropriate option). However, oxygen is also a correct option.
Explanation:
Nitrogen exists on its own as a diatomic gas. However, it exists as organic nitrogen in nucleic acids such as DNA and RNA (as part of their nitrogenous bases) and in the amino (--
) group of amino acids.
Do note that a case can also be made for oxygen as a right option: like nitrogen, it exists as a diatomic gas and can be found in both nucleic acids and in the carboxylic group of amino acids.
Sulfur is not an appropriate option as nitrogenous bases (and nucleic acids) to the best of my knowledge do not contain sulphur although some amino acids like cysteine do.
Carbon is not also an appropriate option because elemental carbon does not exist in gaseous form even though it can be found in both nucleic acids and amino acids.
I believe that most mature soils have three soil horizons. That is Horizon A, Horizon B, and Horizon C. Horizon A, also called the top soil contains a mixture of mineral matter and organic matter, as well as many insects, fungi, and microorganisms. Horizon B, also called the sub soil, contains fine clay particles washed out of horizon A. Horizon C contains partially weathered parent material.
Because it is direct contact of the molecules in the air and the land that are touching.