Cell division in the vascular cambium adds to the girth of a tree by adding new to the layer's interior and to the layer's exterior.

The idea of spontaneous generation was disproved by in a experiment involving jars of meat

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

What is it called when part of a cell membrane closes around a molecule to allow the molecule to enter the cell? a. passive transport b.diffusion c. endocytosis d. exocytosisc. endocytosis