Biology A
Cells Test Review Answer Key
Pp. 197-198: problems 1-10, 12, 14-16, 19, 21-23, 28, 32.
1)D2) B3) B4) B5) C 6) A7) D8) C9) D10) A
12) Prokaryotic and Eukaryotic cells are similar in the fact that they both contain cytoplasm, DNA, and ribosomes. They are different in the fact that the Prokaryotic cell does NOT have a nucleus nor organelles, while a Eukaryotic cell DOES have a nucleus and organelles.
14) Ribosomes assemble proteins
15) The ER is responsible for modifying and shipping proteins throughout the cell.
16) The Golgi Apparatus is used to transport materials out of the cell.
19) The cell membrane is composed of two layers of phospholipids. The sizes of the membrane pores, accessory and carrier proteins will allow certain materials to enter and exit the cell while keeping others out.
21) Diffusion is the process in which molecules move from an area of high concentration toward an area of lower concentration. Once the concentration of molecules is even across an area it is said to be at equilibrium.
22) Osmosis and diffusion both involve materials crossing cell membranes. Diffusion is the movement of solute molecules, whereas by definition, osmosis is the diffusion of water.
23) A cell would be in an isotonic sugar solution if the concentration of sugar were the same both in the internal cellular solution as well as the solution that surrounds the cell. If the surrounding solution had more sugar than the cell, it would be hypertonic. If it had less solute than the cell it would be hypotonic.
28) If red blood cells were placed in a hypotonic solution, water would flood the cell. This is because the cell has more solute inside of it than the surrounding solution.
32) The cell factory:
Nucleus: This would be the supervisor, foreman, or central office. It controls the happenings in the factory.
Endoplasmic Reticulum: This would be a forklift or conveyor belt for transporting things inside the factory.
Ribosome: This would be like the assembly line in the factory.
Golgi Apparatus: This would be like the packaging and shipping center that ships things out of the factory.
Vacuole: This would be like a warehouse or other storage facility.
Mitochondria: This would be like the power generator or power plant that makes energy.
Cell membrane: This would be like the security gate surrounding the factory. It controls what enters and exits the factory.
Lysosome: This would be like the custodians, trash compactor, incinerator etc. It gets rid of waste materials.