Question

which of the following are differences between photosynthesis and cellular respiration?
select all that apply
a photosynthesis and cellular respiration use the same sequence of chemical reactions.
b photosynthesis uses sunlight as an energy source, while cellular respiration uses glucose.
c both processes occur only during the day.
d photosynthesis produces glucose and oxygen, while cellular respiration produces carbon dioxide and water.
e photosynthesis occurs in the chloroplasts, while cellular respiration occurs in the mitochondria.

Explanation:

• Option a: Photosynthesis and cellular respiration have different chemical reaction sequences. Photosynthesis is \(6CO_2 + 6H_2O

ightarrow C_6H_{12}O_6+6O_2\) (using light energy), while cellular respiration is \(C_6H_{12}O_6 + 6O_2
ightarrow6CO_2+6H_2O+\text{energy}\). So, this option is incorrect.

• Option b: Photosynthesis uses sunlight (light energy) to convert \(CO_2\) and \(H_2O\) into glucose (\(C_6H_{12}O_6\)) and \(O_2\). Cellular respiration breaks down glucose (chemical energy) to produce \(CO_2\), \(H_2O\), and ATP. This is a valid difference.
• Option c: Photosynthesis occurs during the day (needs light), but cellular respiration occurs all the time (day and night). So, this option is incorrect.
• Option d: As per the chemical equations above, photosynthesis products (\(C_6H_{12}O_6\) and \(O_2\)) are different from cellular - respiration products (\(CO_2\) and \(H_2O\)). This is a valid difference.
• Option e: Chloroplasts are the site of photosynthesis (contain chlorophyll for light absorption). Mitochondria are the site of (aerobic) cellular respiration (have enzymes for the Krebs cycle and electron - transport chain). This is a valid difference.

Answer:

B. Photosynthesis uses sunlight as an energy source, while cellular respiration uses glucose.
D. Photosynthesis produces glucose and oxygen, while cellular respiration produces carbon dioxide and water.
E. Photosynthesis occurs in the chloroplasts, while cellular respiration occurs in the mitochondria.