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.
Which of these do all prokaryotes and eukaryotes share?
- nuclear envelope
- cell walls
- 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?
Which of the following is not a component of the endomembrane system?
- Golgi apparatus
- endoplasmic reticulum
Which plasma membrane component can be either found on its surface or embedded in the membrane structure?
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 __________.
- 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