Which describes how the atoms in living things cycle? Multiple choice question.

A)
through living parts of ecosystems only

B)
in one direction from living to nonliving parts of the ecosystem

C)
in one direction from nonliving to living parts of the ecosystem

D)
repeatedly back and forth through living and nonliving parts of the ecosystem

D) repeatedly back and forth through living and nonliving parts of the ecosystem

Explanation:

Matter is contained in both living and non-living components of the Earth. An atom is the smallest indivisible component of every matter. This means that matter is made up of atoms.

In an ecosystem, organisms feed on one another in order to survive. However, as they do this, matter is transferred from one organism to another. This transfer of matter (atoms) occurs repeatedly repeatedly back and forth in a cyclical manner through living and nonliving parts of the ecosystem.

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!