LD50 is used to express TOXICITY OF TOXINS AND POISONS.
LD50 stands for Lethal Dose 50. This is the standard measure of the toxicity of a material, which will kill half of the sample population of a particular test animal in a defined time period, when they are exposed to the material.
Plants produce oxygen that animals use for respiration
heart, arteries, and veins
Answer:
b.Their cell walls have very different biochemical properties.
Explanation:
Cellulose is a homopolysaccharide of glucose residues and is the main chemical component of the cell walls of the plant cells. The glucose residues in cellulose are linked together by beta 1-4 glycosidic bonds. Chitin is a linear homopolysaccharide of glucose residues and is the main structural component of the fungal cell wall. On the other hand, peptidoglycan is the major structural component of the bacterial cell walls. Peptidoglycan is a heteropolysaccharide of two different residues. These are N-acetylglucosamine and N-acetylmuramic acid. Therefore, the chemical components and that make the cell walls in plants, fungi and bacteria differ significantly from each other imparting them distinct chemical features.
The answer would be sandstone
