1. The cell wall has lignin (hard substance): to prevent the xylem vessel from collapsing and withstand high pressure.
2. The absence of protoplasm (nucleus + cytoplasm) and cross wall: to allow water to move through the lumen easily.
Hope it helped!
Answer:
Sea floor spreading-> <u><em>Oceanic ridge and Magma pushing two plates apart</em></u>
Continental drift-> <u><em>Concept of pangaea and Oceanic plates sliding under continental crust</em></u>
Explanation:
Due to the divergent plate movement, the magma come out to the surface, forming the mid oceanic ridge and this separation of plates on the sea floor is known as the sea floor spreading. The magma here pushes the two plates to move apart because of the convection current that generates in the mantle. One example of mid oceanic ridge is the Mid-Atlantic Ridge.
Continental drift refers to the slow and gradual movement of the lithospheric plates over the viscous asthenosphere layer. This motion of continents takes place because of the plate tectonic movement. Due to this plate motion, the denser plate gets subducts beneath the less denser plates. For example, the oceanic crust when collides with a continental crust, it gets subducted because of its higher density. The great supercontinent "pangaea" also formed and separated due to this plate motion.
In scientific inquiry, observations can be made in many ways. This includes by using the senses, or performing an experiment.
