The answer is; D
The plasticity of rock in the mantle and the convection currents in the region are responsible for tectonic plate movements. The hot molten rock from deep in the mantle rise and is replaced by the cooler rock at the upper mantle. These convections are similar to those of water in a boiling pot. As the tectonic plates move (as they are dragged by these convections) and collide, earthquakes are caused. In addition, at subductions zones (where two plates collide) there occurs high volcanic activity.
Prokaryotes- lack a cell nucleus, unicellular, in the bacteria and archaea domain, lack mitochondria and chloroplast, microscopic
eukaryotes- contains a cell nucleus, multicellular, only in the eukarya domain, contains mitochondria and chloroplast, not microscopic
answer of the question: B
How would removing your umbrella in a rainstorm affect your ability to stay dry? The definition of a keystone species is a species that has a crucial role in an ecosystem. Removing one gear from a clock would stop the clock from working. Removing/changing a major contributer to a balance and natural ecosystem can potentially collapse the entire system altogether.
