Answer:
The immune, lymphatic, and circulatory systems work together in protecting the body.
Robert Hooke built his own compound microscope to examine tree bark.
Hormones because if you think about it. Vertebrates must have backbones and mammals have them. And, humans are basically mammals. And the glands secrete hormones.
<span>Lakes and ponds are inland bodies of standing or slowly moving water. Although lakes and ponds cover only 2 percent of the world's land surface, they contain most of the world's fresh water. Individual lakes and ponds range in area from a few square meters to thousands of square kilometers. In general, ponds are smaller than lakes, though regional idiosyncrasies of naming abound—Henry David Thoreau's famous Walden Pond in Massachusetts has a surface area of 64 acres. Lakes and ponds are an important source of fresh water for human consumption and are inhabited by a diverse suite of organisms.</span>
Answer:
the food chain
Explanation:
every species in the ecosystem eats or gets eaten
