When elongation of the root stops, you can see that cells begin to take on different functions and have different shapes. what explains this phenomenon?
elongation
germination
differentiation
alternation

The correct answer is "Differentiation".

Differentiation is a process by means of which cells start to form groups and become specialized to perform a particular task. The process of differentiation increases the efficiency of a tissue to accomplish a particular task. Due to differentiation, the structure and shape of cells also changes according to the type of work they are destined to do. It happens in higher organisms where complex body structures exist. Cells differentiate to form tissue and start to show division of labor. A group of tissues further forms organ & organs form organ system. An organ system is specialized to perform only one task with great efficiency. For example, in plants, cells form a group to become xylem tissue which is specialized in only transport of water and does not indulge in any other work.

the answer is b: 1.4 km/hr

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.