Afood chain in an ecosystem flows from green algae, to freshwater snails, to small fish, and finally to large fish. which organism is the primary consumer? large fish small fish green algae freshwater snails

freshwater snails

Explanation:

The food chains are basically divided into three categories, producers, primary consumers, and secondary consumers. The primary consumers in the food chain are the ones that feed upon the producers, thus they are herbivores. In this case, we the green algae as a producer and base of the ecosystem, and the freshwater snail as a primary consumer as it is feeding upon the green algae. Further, the primary consumer is food for the secondary consumers, which are the organisms that are preying on other organisms.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!