Q.Make a list of algae and fungi that have commercial value as source of food, chemicals, medicines and fodder.
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🔒 Start your 14-day free trial to unlock the full solution →Concept understanding — Economic Botany
Economic botany is simply the study of how plants are useful to people — the foods, fuels, medicines and industrial materials we draw from them. It is an everyday idea: think of how much of your day, from the sugar in your tea to the wood in your furniture, traces back to some plant. In the plant kingdom, almost every group turns out to earn its keep in this way, and listing those uses is a good habit because it makes an abstract group of organisms suddenly concrete and memorable.
Running through the major groups, the practical value shows up again and again:
- Algae are surprisingly important. Through photosynthesis they carry out at least half of all carbon dioxide fixation on Earth and raise the oxygen dissolved in water, and they are prime primary producers feeding aquatic food cycles. Many are eaten directly — about seventy species of marine algae, including kinds of Porphyra, Laminaria and Sargassum, are used as human food. Brown algae yield algin and red algae give carrageen, both water-holding hydrocolloids used commercially. Agar, from Gelidium and Gracilaria, is used to grow microbes in the laboratory and in making ice creams and jellies, while the protein-rich single-celled Chlorella serves as a food supplement, even for space travellers.
- Bryophytes have little direct economic value, yet Sphagnum moss yields peat, long burnt as fuel and, because it holds water so well, used as packing material for shipping living plants. Some mosses are food for animals, and mosses with lichens are pioneer colonisers that break down bare rock and, growing as dense mats, cushion raindrops and check soil erosion.
- Pteridophytes are used medicinally, act as soil-binders that hold the soil together, and are grown as ornamental plants. …
Algae and fungi with commercial value include the following, based on what is covered in this chapter:
- Diatoms (Chrysophytes) leave behind diatomaceous earth, a gritty deposit of their silica shells, used commercially in polishing and in filtering oils and syrups.
- Yeast (Saccharomyces), a unicellular fungus, is used in making bread and beer.
- Penicillium is a major source of antibiotics. …
Based on this chapter, commercially valuable algae and fungi include diatoms (diatomaceous earth), yeast, Penicillium and edible mushrooms.
Among the algae-like protists covered here, diatoms stand out commercially. Their silica-embedded, indestructible cell walls accumulate over long periods as diatomaceous earth, a gritty deposit that finds use in polishing and in filtering oils and syrups.
Among the fungi, several members are commercially significant:
- Yeast (Saccharomyces), though a fungus rather than a true multicellular mould, is unicellular and is used extensively in making bread and beer.
- Penicillium is a major source of antibiotics, giving it direct medicinal and commercial value.
- Agaricus, the common mushroom, is eaten as food, and morels and truffles are edible fungi regarded as delicacies. …
- AP EAPCET 2026Set ap-2026-05-19-FN1 markMCQQ.Charas is extracted from this plant (A) Opium poppy plant (B) Indian hemp plant (C) Coca plant (D) Tobacco plant
›Reveal solutionSolution
Charas is one of several cannabinoid drug products (with ganja, marijuana, hashish) derived from the Indian hemp plant, Cannabis sativa.
Concept and Intuition
Several socially and medically significant drugs are derived from Cannabis sativa (Indian hemp): different parts and preparations of the plant yield ganja, charas (resin), marijuana (dried leaves/flowers), hashish, and bhang. These act on cannabinoid receptors in the brain (CB1 receptors), producing altered perception. This is distinct from opium poppy (source of morphine/heroin/opium), coca plant (source of cocaine), and tobacco plant (source of nicotine).
Step-by-Step Solution
- Recall the plant source of charas: it is one of the resinous cannabis preparations from Cannabis sativa, the Indian hemp plant. …
- AP EAPCET 2026Set ap-2026-05-19-AN1 markMCQQ.Identify the medicinal plants among the following A) Datura B) Jatropa C) Arnica D) Azolla E) Chlorella F) Cinchona G) Tea H) Rice (A) A, B, D (B) B, F, H (C) E, F, G (D) A, C, F
›Reveal solutionSolution
Among eight plants, only Datura, Arnica and Cinchona are grown/valued specifically for medicinal compounds.
Concept and Intuition
'Medicinal plants' in the NCERT/board sense are plants whose parts yield compounds used directly in treating disease, as opposed to plants valued for food, fuel, or ecological roles. Recognising each plant's primary economic use is the key discriminator here.
Step-by-Step Solution
- Datura (A): contains tropane alkaloids, used medicinally (e.g., in asthma cigarettes historically, and as a source of anticholinergic compounds) → medicinal.
- Jatropha (B): oil-seed crop used for biodiesel → not medicinal.
- Arnica (C): flowering herb used in topical anti-inflammatory/homeopathic preparations → medicinal.
- Azolla (D): a water fern used as a biofertiliser (nitrogen fixation via Anabaena symbiont) → not medicinal.
- Chlorella (E): a single-celled alga used as a protein/food supplement → not medicinal in the classic sense. …
- AP EAPCET 2025Set ap-2025-05-20-AN1 markMCQQ.Study the following list and match them List - I: A. Blue dye B. Sarasaparilla C. Yellow dye D. Chemical Mutagen List - II: I. Smilax zeylanica II. Butea monosperma III. Indigofera tinctoria IV. Tephrosia purpurea V. Colchicum autumnale (A) A-II, B-V, C-I, D-IV (B) A-III, B-I, C-II, D-V (C) A-III, B-II, C-IV, D-I (D) A-I, B-II, C-III, D-V
›Reveal solutionSolution
Indigo (blue dye) from Indigofera tinctoria, sarsaparilla from Smilax zeylanica,
yellow dye from Butea monosperma, and colchicine (chemical mutagen) from Colchicum
autumnale — giving A-III, B-I, C-II, D-V.
Concept and Intuition
This matches economically/pharmacologically important plant-derived products to their
source plants — a standard "economic botany" fact set:
- Indigofera tinctoria is the traditional source of indigo, the classic deep blue dye historically used for textiles.
- Smilax zeylanica (a climbing shrub) is the botanical source of sarsaparilla, used in traditional tonics/flavourings.
- Butea monosperma ("Flame of the Forest", Palash/Tesu) produces flowers that yield a bright yellow-orange dye, traditionally associated with the festival of Holi.
- Colchicum autumnale (autumn crocus) is the source of colchicine, a well-known chemical mutagen that inhibits spindle fibre formation during cell division, widely used to induce polyploidy in plant breeding.
Step-by-Step Solution
- A. Blue dye → Indigofera tinctoria (III).
- B. Sarsaparilla → Smilax zeylanica (I).
- C. Yellow dye → Butea monosperma (II). …
- AP EAPCET 2025Set ap-2025-05-20-FN1 markMCQQ.Choose the correct statements among the following I. Krishi Parasaram describes different types of forests. II. Hieroglyphics are related to the crop plants in the form of pictures. III. Jatropha and pongamia are rich in hydrocarbons. IV. C.G.K. Ramanujan studied the crystalization of enzyme urease. (A) I, II (B) II, III (C) III, IV (D) II, IV
›Reveal solutionSolution
The question tests knowledge of historical and scientific facts in agriculture and biochemistry. Only statements II and III are correct, so the answer is option (B).
This problem is a classic multiple-choice fact-checking exercise. It mixes history (Krishi Parasaram, hieroglyphics), botany (hydrocarbon-rich plants), and biochemistry (enzyme crystallization). The key is to recall or reason about each statement independently, then see which combination matches the options.
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Statement I: "Krishi Parasaram describes different types of forests."
Krishi Parasaram is an ancient Indian agricultural text attributed to the sage Parashara. It deals with farming practices, soil types, seasons, and crop cultivation — not forest classification. The description of forests is more associated with texts like the Arthashastra or Vrikshayurveda. Thus, this statement is false.
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Statement II: "Hieroglyphics are related to the crop plants in the form of pictures."
Hieroglyphics were the writing system of ancient Egypt, using pictorial symbols. Many of these symbols depicted crops like wheat, barley, and flax, representing agricultural life. So this statement is true.
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Statement III: "Jatropha and pongamia are rich in hydrocarbons."
Both Jatropha curcas and Pongamia pinnata (also called karanj) produce seeds with high oil content. Their oils are rich in triglycerides (hydrocarbon-based compounds) and are used for biodiesel production. Hence, this statement is true.
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Statement IV: "C.G.K. Ramanujan studied the crystallization of enzyme urease." …
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- AP EAPCET 2025Set ap-2025-05-20-FN1 markMCQQ.Match the following List-I / List-II A) Berry - I) Indian Rose wood B) Medicine - II) Allium C) Spice - III) Solanum D) Timber - IV) Ashwagandha (A) A-III, B-IV, C-II, D-I (B) A-I, B-III, C-IV, D-II (C) A-IV, B-II, C-I, D-III (D) A-III, B-I, C-II, D-IV
›Reveal solutionSolution
Matching plant-use categories to genus examples: Berry–Solanum, Medicine–Ashwagandha, Spice–Allium, Timber–Indian Rosewood, giving A-III, B-IV, C-II, D-I, option (A).
Concept and Intuition
Economically important plants are grouped by the plant part/product humans use. Recognizing a genus's typical economic role (fruit type, medicinal, culinary spice, or wood) is a recurring memorisation-based question type.
Step-by-Step Solution
- A) Berry → III) Solanum: tomato and brinjal (both Solanum species) are classic true berries — fleshy pericarp with embedded seeds, no stone.
- B) Medicine → IV) Ashwagandha (Withania somnifera): a well-known medicinal plant used in Ayurveda.
- C) Spice → II) Allium: onion and garlic (genus Allium) are used as spices/flavouring agents. …
- AP EAPCET 2023Set ap-2023-05-23-AN1 markMCQQ.Match the following List I: I) Makoi, II) Red dragon, III) Sarasaparilla, IV) Night queen List II: A) Dracaena aungustifolia, B) Smilax zeylanica, C) Cestrum nocturnum, D) Solanum nigrum (A) I C, II A, III D, IV B (B) I B, II D, III A, IV C (C) I C, II D, III A, IV B (D) I D, II A, III B, IV C
›Reveal solutionSolution
This tests recall of common (vernacular) plant names matched to their correct scientific (binomial) names.
Concept and Intuition
Many ornamental and medicinal plants are far better known by regional/common names than by their Latin binomials; connecting the two is a standard taxonomy exercise.
Step-by-Step Solution
- Makoi is the common (Hindi) name for black nightshade, scientifically Solanum nigrum. So I → D.
- Red dragon refers to a Dracaena species (dragon plant), matching Dracaena angustifolia. So II → A.
- Sarsaparilla is the common name for Smilax zeylanica, a climbing shrub used medicinally. So III → B.
- Night queen ("Raat ki Rani") is the fragrant night-blooming Cestrum nocturnum. So IV → C. …
- AP EAPCET 2021Set ap-2021-09-03-AN1 markMCQQ.Assertion (A): Petro plants yield Bio-diesel Reason (R): Jatropa is rich in hydrocarbons (A) A is correct but R is wrong (B) Both A and R are correct and R is the correct explanation for A (C) A is wrong but R is correct (D) Both A and R are correct and R is not the correct explanation for A
›Reveal solutionSolution
This assertion-reason tests knowledge of petro-crops/energy plantations. Both statements are true, and the hydrocarbon-rich nature of Jatropha's oil is exactly why it is processed into bio-diesel.
Concept and Intuition
"Petro-plants" or "petro-crops" is the name given to plants explored as renewable substitutes for fossil fuels because their oil/latex is rich in long-chain hydrocarbon-based compounds. Jatropha curcas is the flagship Indian example — its seeds yield a non-edible oil that is chemically rich in hydrocarbon (fatty-acid) chains, which makes it an excellent feedstock for bio-diesel production.
Step-by-Step Solution
- Assertion: "Petro plants yield bio-diesel" — true; this is precisely the economic/ecological rationale for growing petro-crops like Jatropha.
- Reason: "Jatropha is rich in hydrocarbons" — true; its seed oil's hydrocarbon-rich composition is what allows it to be converted into a diesel substitute. …
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