<span>Variation among individuals in a species is real and important.</span>
Living things consists of the organisms like the plants, animals, fungi, protozoa and bacteria. These animals vary in the complexity of the body and have different number of cells in their body. Organisms like the plants and animals are made up of several different kinds of cells. These organisms are called multi-cellular organisms. On the other hand, organisms like the baker's yeast (a fungi) and a plethora of bacteria are single celled organisms. They are called unicellular organisms. Hence we can say that the living things are made up of at least one cell.
Answer:
Reproduction is the ability of living organisms to give rise to new individuals of the same species.
Respiratory system includes all the structures and organs of living organisms associated with the process of taking oxygen into the body and giving out carbon dioxide and water vapour into the environment.
B, hormones that serve as chemical messengers im not 100% sure though