Answer:
The invention of the electron microscope allowed them to see organelles and other structures smaller than cells. There is variation in cells, but all cells have a plasma membrane, cytoplasm, ribosomes, and DNA. These similarities show that all life on Earth has a common ancestor in the distant past
Answer:
B. Allows for specialized regions with specialized functions
Explanation:
Where the complete digestive system has different specialized regions to perform specialized functions, the gastrovascular cavity is the primary organ of digestion and circulation in two major animal phyla: the Cnidaria (including jellyfish and corals) and Platyhelminthes (flatworms).
In comparison they both show feeding relationship in an ecosystem.
In contrast, a food chain is a simple linear feeding relationship while a food web is a complex feeding relationship.
2) The arrows is to show the direction of the feeding relationship