Earth surface is curved, not flat. Due to the curved earth surface, some part of the earth surface gets direct and straight solar radiations than others.
For example, the regions located near equator get direct and straight solar radiations imparting them higher temperature. On the other hand, the regions near poles obtain slant solar radiations. This is the reason that polar regions have colder climatic conditions.
When stem cells grown on hard, rigid surface, then they became bone cells. Researchers demonstrate in Nature materials that human mesenchymal stem cells grown on a rigid substrate for some time become biased toward differentiating into bone-cell lineage, whereas cell grown on softer surfaces are just likely to eventually follow a bone or fat cell fate.
Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells
