When viewing a specimen through a light microscope, scientists use _________ to distinguish the individual components of cells.
- a beam of electrons
- radioactive isotopes
- special stains
- high temperatures
The ___________ is the basic unit of life.
- organism
- cell
- tissue
- organ
Which of these do all prokaryotes and eukaryotes share?
- nuclear envelope
- cell walls
- organelles
- plasma membrane
A typical prokaryotic cell __________________ compared to a eukaryotic cell.
- is smaller in size by a factor of 100
- is similar in size
- is smaller in size by a factor of one million
- is larger in size by a factor of 10
Which of the following is found both in eukaryotic and prokaryotic cells?
- nucleus
- mitochondrion
- vacuole
- ribosome
Which of the following is not a component of the endomembrane system?
- mitochondrion
- Golgi apparatus
- endoplasmic reticulum
- lysosome
Which plasma membrane component can be either found on its surface or embedded in the membrane structure?
- protein
- cholesterol
- carbohydrate
- phospholipid
The tails of the phospholipids of the plasma membrane are composed of _____ and are _______?
- phosphate groups; hydrophobic
- fatty acid groups; hydrophilic
- phosphate groups; hydrophilic
- fatty acid groups; hydrophobic
Water moves via osmosis _________.
- throughout the cytoplasm
- from an area with a high concentration of other solutes to a lower one
- from an area with a low concentration of solutes to an area with a higher one
- from an area with a low concentration of water to one of higher concentration
The principal force driving movement in diffusion is __________.
- temperature
- particle size
- concentration gradient
- membrane surface area
Active transport must function continuously because __________.
- plasma membranes wear out
- cells must be in constant motion
- facilitated transport opposes active transport
- diffusion is constantly moving the solutes in the other direction