Because things take time to grow
Answer: For building amino acids, proteins and nucleic acids.
Explanation:
Living cells requires nitrogen because they are major part of amino acids. They form the building block of protein and nucleic acids such as DNA which carry the genetic information and is passed from generations to generations. Plants and animal need nitrogen for growth and survival. The protein is use for building and repairing muscles and it is a necessity for growth.
Bones consist of living cells embedded in a mineralized organic matrix. This matrix consists of organic components, mainly type I collagen – "organic" referring to materials produced as a result of the human body – and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate.
They are also called "Land Plants" that are non-vascular!
Hope this helps!
B because a new species adds more diversity to your ecosystem