Pioneer species such as lichen and moss inhabit an area after a major disturbance such as a volcanic eruption. Over time, other species are found in the disturbed area and the number of pioneer species decreases. Why does the number of pioneer species decrease? The amount of available sunlight is reduced. The pioneer species can no longer thrive. ⊝ The area has more soil to support complex plants. The competition increases between organisms. ⊝ The area is more susceptible to the wind. Seeds are captured in the pioneer plants and germinate at a higher rate. ⊝ The temperature is not as extreme as it was following the disturbance. Fewer of the pioneer species reproduce. ⊝ CLEAR ALL

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!

the answer is c a tornado