Which of the following plants is not capable of manufacturing its own food by photosynthesis?

Introduction / Context:
This question tests your understanding of autotrophic and heterotrophic nutrition in biology. Green plants and some plant like organisms are capable of photosynthesis, using chlorophyll, sunlight, carbon dioxide, and water to make their own food. Other organisms lack chlorophyll and must obtain food from external sources. The question asks which listed organism cannot manufacture its own food, highlighting the difference between true plants and fungi.

Given Data / Assumptions:

• Options are algae, mushroom, carrot, and cabbage, with an additional None of the above choice.
• We assume normal, healthy examples of each organism.
• We use the standard definition of photosynthesis: conversion of light energy into chemical energy using chlorophyll.

Concept / Approach:
Algae, carrot plants, and cabbage are all photosynthetic organisms that contain chlorophyll in their green parts. Algae, though diverse, are generally considered autotrophic and capable of photosynthesis. Carrot and cabbage are typical green plants; their leaves produce food through photosynthesis, although the carrot root stores food. Mushrooms, however, belong to the kingdom Fungi. Fungi do not have chlorophyll and cannot photosynthesise; they obtain nutrients by decomposing organic matter or forming parasitic or symbiotic relationships. Thus, mushrooms cannot manufacture their own food and are heterotrophic.

Step-by-Step Solution:
Step 1: Evaluate algae: Most algae contain chlorophyll and live in water, performing photosynthesis like plants. Step 2: Evaluate carrot: The carrot plant has green leaves that photosynthesise; the orange root is a storage organ for food made by the leaves. Step 3: Evaluate cabbage: Cabbage leaves are green and rich in chlorophyll, so the plant manufactures its own food. Step 4: Evaluate mushroom: Mushrooms are fungi, lack chlorophyll, and cannot use sunlight to make food. Step 5: Conclude that mushroom is the only organism in the list that is not capable of manufacturing its own food.

Verification / Alternative check:
Biology textbooks classify organisms by their mode of nutrition. Autotrophs, such as green plants and algae, synthesise food using photosynthesis. Heterotrophs, including animals and fungi, rely on external organic sources. Mushrooms are regularly cited as classic examples of saprophytic fungi that decompose dead organic matter. Carrot and cabbage appear as typical garden vegetables and are always included among plants that produce their own food. This classification strongly supports mushroom as the correct answer.

Why Other Options Are Wrong:
Algae: Most algae are photosynthetic autotrophs and can manufacture their own food. Carrot: The carrot plant is a green plant; though the edible root is underground, the plant as a whole performs photosynthesis. Cabbage: A leafy vegetable with chlorophyll containing leaves that photosynthesise and produce food for the plant. None of the above: Incorrect because one listed organism, the mushroom, clearly cannot photosynthesise.

Common Pitfalls:
Some students may be misled by the fact that mushrooms grow from the ground like plants and are eaten as vegetables, causing them to overlook that mushrooms are fungi, not plants. Others might mistakenly think carrots cannot photosynthesise because the root is underground, forgetting that photosynthesis occurs in the leaves. To answer correctly, remember that green colour from chlorophyll is a strong indicator of photosynthesis, and fungi like mushrooms lack this pigment.

Final Answer:
The plant among the options that is not capable of manufacturing its own food is the mushroom, because it is a fungus and heterotrophic.