Explanation:
the name porifera means pore bearer in latin. a sponges body is covered by a skin, one cell thick. this skin has lots of small pores ad a few large openings. the small openings are the entrances to a complex system of channels. these collar cells pump water through the entire sponge and filter out food for the sponge cell to eat
Explanation:
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells.
cells are bigger than atoms. We can see cells with a microscope. Just as atoms have smaller parts called protons, neutrons, and electrons, cells have smaller parts, too. When you look at cells with a powerful microscope, you can clearly see hundreds of them.
Caused by sexual contact are more difficult to treat..
Photosynthesis is an example of how people and plants are dependent on each other.
