Circulatory and Respiratory systems working together to provide body with oxygen.
A DNA mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people. Mutations range in size; they can affect anywhere from a single DNA building block (base pair) to a large segment of a chromosome that includes multiple genes. DNA mutations can affect an offspring can result in abnormal protein products. Mutations can also introduce new alleles into a population of organisms and increase the population's genetic variation.
Answer:
In plants and algae, which developed much later, photosynthesis occurs in a specialized intracellular organelle—the chloroplast. Chloroplasts perform photosynthesis during the daylight hours. The immediate products of photosynthesis, NADPH and ATP, are used by the photosynthetic cells to produce many organic molecules.
I'd say C. an allergic reaction. Mainly because lots of people are allergic to many things and many people intend to have seasonal allergies cause by plants. Hope it helps!