Unit 2 Cell Review

Cells of different organisms are so diverse that it is impossible to come up with a law that would apply to all of them.

Because cells undergo change as mutations occur within them, developing anything beyond a cell theory would be impractical.

Scientific theories are well-tested explanations, while laws are well-tested descriptions of natural phenomena; one cannot become the other.

Scientific theories can only become laws if all possible cases can be tested; it would be impossible to test all living things to see if they have cells.

All living things are made of cells.

All cells come from other preexisting cells.

Cells form through spontaneous generation.

Cells are the basic structural and functional units of life.

Cells are produced from existing cells

Cells are the basic units of structure in living things

All cells have the same internal structure

All living things are made of cells

cell wall, ribosomes and nucleus

cell membrane, nucleus, mitochondria

cell membrane, cytoplasm and ribosomes

chloroplast, cell membrane and cytoplasm

Eukaryotic cells have a nucleus and membrane-bound organelles; prokaryotic cells lack these features.

Eukaryotic cells have fewer distinct parts than prokaryotic cells because they are less evolved.

Eukaryotic cells do not have cell walls or vacuoles; prokaryotic cells have both of these features.

Eukaryotic cells reproduce using DNA; prokaryotic cells use RNA only to reproduce.

Lysosome

Mitochondria

Nucleus

Ribosome

nucleus, mitochondria, chloroplasts

cell wall, mitochondria, Golgi apparatus

central vacuole, Golgi apparatus, nucleus

chloroplasts, cell wall, central vacuole

mitochondrion . . . cellular energy

ribosome . . . manufacture of proteins

lysosome . . . movement

central vacuole . . . storage

A

B

C

D

Passive transport does not require chemical energy to occur; active transport requires energy, such as ATP.

Passive transport happens only in the presence of water, while active transport does not require water to occur.

Passive transport moves larger substances through the cell membrane; smaller molecules must move by active transport.

Passive transport allows whole particles to move through the membrane, while active transport breaks particles down before they can pass through.

vacuole

cell membrane

nucleus

mitochondria

Active transport

Passive transport

Facilitated diffusion

Co-transport

perforated

semi-permeable

non-conductive

permeable