Flatworms absorb oxygen by diffusion mechanism through their
skin to the cells in their bodies. Since flatworms do not have a circulatory system,
their bodies' cells are positioned close to the skin to ease the uptake of
oxygen from surrounding fluids or water.
The term that best completes the statement is PROTISTA. It is the Kingdom protista that is considered heterogeneous because it both consists of eukaryotes that are unicellular and multicellular but these cannot be classified as either an animal or a plant.
Answer:
Horsetails vary in appearance, but they all lack leaves and have no close relatives. The most similar group of plants are the ferns. They use both their branches and their stems for photosynthesis, as opposed to having foliage. The stalks of the horsetails are almost hollow in the center.
Explanation:
