The blade is the flattened portion of the leaf. These expanded blades are called lamina which are attached to the plant stem by the petiole. They come in diverse shapes, sizes, and other characteristics. The other choices are just supporting structures of this structure of the plant.
Three<span> major </span>types of RNA<span> are mRNA, or messenger </span>RNA<span>, that serve as temporary copies of the information found in DNA; rRNA, or ribosomal </span>RNA<span>, that serve as structural components of protein-making structures known as ribosomes; and finally, tRNA, or transfer </span>RNA<span>, that ferry amino acids to the ribosome to be assembled</span>
Half of the number of the chromosomal numbers of the diploid cell.
I believe it's A. because the bone matrix is where it goes, therefore the bone matrix is already there. it just maintains it