Question

When a photosynthetic plant is transferred to an atmosphere of enriched O$_2$ its rate of
A. Photosynthesis would increase
B. Photosynthesis would decrease
C. Respiration would decrease
D. Osmosis would increase

Answer 1

Hint: It is essential to know that out of the many factors that have an effect on chemical change once the quantity of O$_2$ within the atmosphere will increase the speed of chemical change is reduced. When O$_2$ concentration is more in atmosphere photosynthesis rate increases in C$_3$ plants.

Complete answer: There are several variables that are the limiting factors of photosynthesis suggested by Blackman. When the photosynthetic plant is moved to a more oxygen-concentrated atmosphere, the rate of photosynthesis will decrease. Optimum levels of elements are favorable for chemical change. Oxygen is required for photorespiration in C$_3$ plants and therefore the by-product of photorespiration is carbonic acid gas that is important for chemical change. Also, the energy generated throughout the element respiration is required for the method of chemical change similarly. However, a rise within the element levels on the far side of the optimum for the plant ends up in inhibition of chemical change. This is as a result of an element that tends to interrupt down the intermediaries that are a unit shaped in a chemical change. Element additionally completes with carbonic acid gas to mix with RuBisCO that is a neighborhood of the dark reaction of chemical change and photorespiration. Therefore, Blackman’s Principle of Limiting Factors principle states that once a method is ruled by quite one factor, the speed of the method is ruled by that factor that is nearest to its minimum value.
Hence, the correct answer is option B-Photosynthesis would decrease.

Note: The accrued levels of O$_2$ would mean that RuBisCO can mix with O$_2$ to initiate photorespiration and chemical change can block. For example, if a leaf is exposed to an explicit quantity of sunshine intensity with constant temperature however the dioxide offered is a smaller amount, the speed of chemical change won't increase with a rise within the strength. Therefore, in this case, dioxide is the limiting issue.