AP BIOLOGY

Detailed explanation-1: -Cell – a membrane covered structure that contains all the materials necessary for life – the smallest unit / the building blocks of life. Plant cells are eukaryotic and contain three extra organelles (chloroplasts, cell walls and vacuoles).

Detailed explanation-2: -A cell is a membrane-covered structure that contains all of the materials necessary for life. Cells are the smallest unit of life, which means they are the smallest structures that can perform life functions.

Detailed explanation-3: -The plasma membrane is the outer covering of cells. they are necessary for cells because : They form a barrier between the cell and outer environment, thus keeping it safe for long. They are selectively permeable in nature, thus keeps a check on the movement of substances from in and out of the cell.

Detailed explanation-4: -The plasma membrane, or the cell membrane, provides protection for a cell. It also provides a fixed environment inside the cell, and that membrane has several different functions. One is to transport nutrients into the cell and also to transport toxic substances out of the cell.