Question

1. When you put aspirated spinach leaf disks in a beaker of sodium bicarbonate and place them in different colors of light, some disks float faster & more abundantly than others dependent on what color, if any, they were in. What made them able to float?

   	A.	The release of O2 from the process of respiration.
   	B.	The release of O2 from the process of photosynthesis.
   	C.	The green light condition/treatment.
   	D.	The release of CO2 from the process of photosynthesis.
   	E.	The sodium bicarbonate dissolving the cholorphyll in the leaf.

Answer 1

Photosynthesis is a process of energy production performed by chlorophyll-containing organisms such as plants. They use the sunlight( photon), water and carbon dioxide( source of carbon) to produce ATP or adenosine triphosphate and oxygen which is released by the leaves into the atmosphere.

The source of carbon dioxide is the atmosphere from where the leaves intake CO2.

Sodium bicarbonate is a chemical compound with the formula NAHCO₃. As it contains carbon atoms, therefore when spinach leave disks are dipped into the solution containing NAHCO3, this C acts as the carbon source for photosynthesis. As photosynthesis takes place, the leave disks absorb carbon and sink to the bottom of the beaker. When oxygen is produced as the by-product of the photosynthesis reaction, it is released by the stomata. This release of O2 provides the buoyancy which causes the leaves to float upwards i.e towards the surface of the beaker.

Hence, the correct answer choice is OPTION B.

** During aerobic respiration, Oxygen is absorbed to perform the reaction. Plants reflect green light and absorb red light more to perform photosynthesis. The effect of green light has no part in the floating of the leaves. However, if the leaves are placed under red light condition, the rate of photosynthesis will be higher and leaves will float faster. Sodium bicarbonate doesn't dissolve the chlorophyll, also NAHCO3, when used, resulting in the growth of plants which is observed in many types of research.