They develop into the cell wall and cell membrane
I would say D because mechanical weathering is the breaking up of rocks by physical forces
The correct option is A.
Proactive interference refers to the tendency of the knowledge that one had learned previously to prevent one from subsequent learning. Thus, proactive interference is the difficulty that comes with learning new things due to the stuffs that one had learned before. For instance, an individual may find it difficult to learn Spanish because he has previously learn German.<span />
Plants get their required nutrients from the soil.
The correct answer is an accumulation of microorganisms in deep marine environments.
Chalk rock refers to a pure form of limestone produced in tropical and warm seas about 100 million years ago in the Cretaceous period. The microscopic marine algae known as coccoliths thrived in the ancient seas. Their shells were comprised of calcite. With the death of the algae, their bodies sunk to the floor of the sea and sediment of chalk got deposited.
Over many years layers of chalk sediment got deposited and resulted in compaction of loose sediment into solid chalk rock.
