What is a closed system? A. A system that allows energy and mass to move in or out of it

B. A system that does not allow energy or mass to move in or out of
it
C. A system that allows mass to move in and out but not energy

D. A system that allows energy to move in and out but not mass

The climate of the continental united states is generally 1. tropical 2. temperate 3. arctic 4. highland

Which of these conditions most likely produces an unstable isotope?

What will most likely happen in the absence of a cell membrane? a) photosynthesis will not take place. b) the cell will not store food, water, nutrients, and waste. c) energy will not be released during cellular respiration. d) substances will pass in and out of the cell in an uncontrolled manner.