Cell Structure and Organization — Practice Quiz

All living organisms are made up of cells, Living cells arise from pre-existing cells, Cells contain nucleic acids DNA and RNA, Cells show transformation of energy

Modern cell theory includes several postulates: all living organisms are made of cells, cells arise from pre-existing cells, cells are structural and functional units, they contain DNA and RNA, and show energy transformation. Only plants being made of cells is incorrect as animals are also made of cells.

Fluid mosaic model

The fluid mosaic model proposed by Singer and Nicholson in 1972 explains cell membrane structure as a phospholipid bilayer with proteins embedded like icebergs in a sea of lipids. Other models are for different biological structures.

Ribosomes, Rough Endoplasmic Reticulum, Mitochondria, Nucleus

Ribosomes are the actual protein factories. Rough ER has ribosomes attached and is involved in synthesis of secretory proteins. Nucleus provides genetic information (mRNA) for protein synthesis. Golgi modifies proteins but doesn't synthesize them. Mitochondria are involved in energy production.

Can digest the cell's own components

Lysosomes are called suicide bags because they contain hydrolytic enzymes that can digest the cell's own components through autophagy when the cell is damaged or during programmed cell death. They form autophagic vesicles for this purpose.