Si la corteza terrestre estuviera expuesta sólo a los procesos de erosión, toda la superficie del globo fuera una superficie. ¿De dónde procede la energía que permite la producción de
estructuras nuevas en nuestro globo terráqueo?

A. Energía hidráulica
B. Energía potencial
C. Energía geotermal
D. Energía de superficie

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.

lichens that colonize bare rock secrete acids that break down the rock and start the soil-production process. so they expose rocks