The photosynthesis reaction of plants occurs in the presence of?

Appeared in: MNS 2015

Explanation

Photosynthesis is a process that converts light energy into chemical energy, requiring a photosensitive pigment to capture sunlight.
In plants, Chlorophyll is the primary pigment responsible for absorbing light energy, which is analogous to how pigments like rhodopsin function in human vision by absorbing light.
This captured energy drives the synthesis of glucose (food) from carbon dioxide and water within the plant's chloroplasts.
The presence of chlorophyll is the defining requirement for a plant to be able to perform the photosynthetic reaction.

Option A: Xanthophylls are accessory pigments in plants. While they do absorb light, they are not the primary pigment that drives the core reactions of photosynthesis; they transfer the absorbed energy to chlorophyll.
Option B: A truffle is a type of subterranean fungus. Fungi are heterotrophs, meaning they cannot produce their own food and lack the chlorophyll necessary for photosynthesis.
Option C: Yeast is a single-celled fungus. Like all fungi, it does not contain chlorophyll and cannot perform photosynthesis. It obtains energy through fermentation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain The primary pigment required for photosynthesis in plants as background academic context rather than a clinical decision trigger.
Photosynthesis is the foundational biological process that produces most of the oxygen in our atmosphere, which is essential for respiration in humans and animals.
It is the basis of nearly all food chains on Earth, as it converts inorganic materials into organic compounds that sustain life.
Understanding photosynthesis is crucial in fields like agriculture for optimizing crop yields and in environmental science for studying carbon cycles and climate change.

How to Approach the Question

First, identify the key process in the question stem: 'photosynthesis reaction of plants'.
Recall the basic definition and requirements of photosynthesis. It's the process where plants make their own food using sunlight.
Analyze the options provided in the context of this process.
Evaluate each option's role: Truffle and Yeast are fungi, which are known to be decomposers or parasites, not producers; they don't photosynthesize.
Differentiate between the remaining options: Xanthophylls and Chlorophyll are both plant pigments. Recall that chlorophyll is the primary green pigment responsible for capturing light energy.
Conclude that chlorophyll is the essential component in whose presence the reaction occurs, making it the correct answer.

Concept Tested & Keywords

QxN1YbVcOJiQrAO1pw7kOt

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 406-408

E6 Physiology Guyton 4SAE Part 3 p. 151-153

Practise the full MNS 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.