Part 5 — Lichens (Q101–Q125)
Part 5 — Lichens (Q101–Q125)
25 MCQs on structure, symbiotic partners, types of lichens, ecological roles, and use as bioindicators.
Q101. Lichens are a symbiotic association between:
- A. Algae and fungi
- B. Bacteria and fungi
- C. Virus and algae
- D. Bacteria and algae
Answer: A
- A: Correct — lichens consist of a fungal partner (mycobiont) and algal partner (phycobiont).
- B: Incorrect — bacteria are not primary partners.
- C: Incorrect — viruses are not involved.
- D: Incorrect — not the usual association.
Q102. The algal partner in lichen provides:
- A. Minerals
- B. Protection
- C. Organic food by photosynthesis
- D. Water only
Answer: C
- A: Incorrect — minerals absorbed by fungus.
- B: Incorrect — fungus provides protection.
- C: Correct — algae photosynthesize and provide carbohydrates.
- D: Incorrect — water absorbed by fungus.
Q103. The fungal partner in lichen provides:
- A. Carbohydrates
- B. Water and mineral absorption + shelter
- C. Nitrogen fixation
- D. Pigments
Answer: B
- A: Incorrect — carbohydrates are from algae.
- B: Correct — fungi absorb minerals, retain water, and protect algae.
- C: Incorrect — nitrogen fixation is by cyanobacteria.
- D: Incorrect — pigments not the main function.
Q104. Lichens are sensitive to:
- A. Carbon dioxide
- B. Sulphur dioxide
- C. Oxygen
- D. Nitrogen
Answer: B
- A: Incorrect — they tolerate normal CO₂.
- B: Correct — lichens are pollution indicators, very sensitive to SO₂.
- C: Incorrect — oxygen not harmful.
- D: Incorrect — nitrogen not main factor.
Q105. Which type of lichen appears leafy?
- A. Crustose
- B. Foliose
- C. Fruticose
- D. Squamulose
Answer: B
- A: Incorrect — crustose form thin crusts.
- B: Correct — foliose lichens are leaf-like.
- C: Incorrect — fruticose are shrubby/branched.
- D: Incorrect — squamulose intermediate forms.
Q106. Crustose lichens are characterized by:
- A. Leaf-like body
- B. Crust tightly attached to substrate
- C. Shrub-like branches
- D. Loose thallus
Answer: B
- A: Incorrect — foliose.
- B: Correct — crustose are thin, crusty, adherent.
- C: Incorrect — fruticose.
- D: Incorrect.
Q107. Fruticose lichens are:
- A. Crust-like
- B. Shrub-like, branched
- C. Leafy
- D. Filamentous
Answer: B
- A: Incorrect.
- B: Correct — fruticose lichens are branched, bushy.
- C: Incorrect.
- D: Incorrect.
Q108. Which of the following is a common algal partner in lichens?
- A. Nostoc
- B. Oscillatoria
- C. Volvox
- D. Euglena
Answer: A
- A: Correct — cyanobacterium Nostoc often partners.
- B: Incorrect.
- C: Incorrect.
- D: Incorrect.
Q109. Lichens reproduce mainly by:
- A. Seeds
- B. Soredia and isidia
- C. Binary fission
- D. Conjugation
Answer: B
- A: Incorrect — not seed plants.
- B: Correct — small fragments containing both partners (soredia, isidia).
- C: Incorrect — fission in bacteria.
- D: Incorrect.
Q110. Economic importance of lichens includes:
- A. Dyes, perfumes, food
- B. Nitrogen fixation only
- C. Antibiotics only
- D. None
Answer: A
- A: Correct — lichens used as dyes (litmus), perfumes, food.
- B: Incorrect.
- C: Incorrect — some antibiotic value but not only.
- D: Incorrect.
Q111. Lichens are pioneer species in:
- A. Forests
- B. Deserts
- C. Bare rocks
- D. Oceans
Answer: C
- A: Incorrect.
- B: Incorrect.
- C: Correct — lichens colonize bare rocks, produce soil.
- D: Incorrect.
Q112. Phycobiont in lichen is generally:
- A. Algae
- B. Fungus
- C. Bacteria
- D. Protozoa
Answer: A
- A: Correct — algal component.
- B: Incorrect — fungus is mycobiont.
- C: Incorrect.
- D: Incorrect.
Q113. Mycobiont in lichen is usually:
- A. Cyanobacterium
- B. Fungus
- C. Green alga
- D. Protozoan
Answer: B
- A: Incorrect.
- B: Correct — fungal partner.
- C: Incorrect.
- D: Incorrect.
Q114. Which type of lichen forms colorful patches on rocks?
- A. Foliose
- B. Crustose
- C. Fruticose
- D. Squamulose
Answer: B
- A: Incorrect.
- B: Correct — crustose often form colorful crusts.
- C: Incorrect.
- D: Incorrect.
Q115. The ecological role of lichens includes:
- A. Bioindicators of air pollution
- B. Soil formation
- C. Primary colonizers
- D. All of these
Answer: D
- A: Correct.
- B: Correct.
- C: Correct.
- D: Correct — all roles.
Q116. Lichens are absent in:
- A. Polluted urban areas
- B. Tundra
- C. Deserts
- D. Forests
Answer: A
- A: Correct — they die in SO₂-polluted air.
- B: Incorrect — lichens survive in tundra.
- C: Incorrect.
- D: Incorrect.
Q117. Reindeer moss (Cladonia) is actually a:
- A. Bryophyte
- B. Lichen
- C. Fern
- D. Gymnosperm
Answer: B
- A: Incorrect.
- B: Correct — Cladonia rangiferina is fruticose lichen.
- C: Incorrect.
- D: Incorrect.
Q118. The algal partner in lichens is also called:
- A. Mycobiont
- B. Phycobiont
- C. Sporophyte
- D. Gametophyte
Answer: B
- A: Incorrect — fungus.
- B: Correct — algal partner.
- C: Incorrect.
- D: Incorrect.
Q119. The fungal partner in lichens is also called:
- A. Mycobiont
- B. Phycobiont
- C. Sporophyte
- D. Zygote
Answer: A
- A: Correct — fungal partner = mycobiont.
- B: Incorrect.
- C: Incorrect.
- D: Incorrect.
Q120. Lichens are resistant to:
- A. Extreme cold and drought
- B. Air pollution
- C. Sulphur dioxide
- D. Industrial smoke
Answer: A
- A: Correct — lichens tolerate extreme cold/drought.
- B: Incorrect — they are sensitive to air pollution.
- C: Incorrect — SO₂ is lethal.
- D: Incorrect.
Q121. Lichens are considered as:
- A. Autotrophs only
- B. Heterotrophs only
- C. Composite organisms
- D. Saprophytes
Answer: C
- A: Incorrect.
- B: Incorrect.
- C: Correct — combination of fungus + alga.
- D: Incorrect.
Q122. In lichens, photosynthesis is carried out by:
- A. Fungal partner
- B. Algal partner
- C. Both partners
- D. Neither
Answer: B
- A: Incorrect.
- B: Correct — algae or cyanobacteria photosynthesize.
- C: Incorrect.
- D: Incorrect.
Q123. Some lichens fix nitrogen because:
- A. Algal partner is green algae
- B. Fungal partner is basidiomycete
- C. Algal partner is cyanobacterium
- D. Fungal partner is zygomycete
Answer: C
- A: Incorrect.
- B: Incorrect.
- C: Correct — cyanobacteria like Nostoc fix nitrogen.
- D: Incorrect.
Q124. Lichens help in rock weathering by:
- A. Mechanical penetration
- B. Secreting acids
- C. Both A and B
- D. None
Answer: C
- A: Partly correct.
- B: Partly correct.
- C: Correct — both mechanisms operate.
- D: Incorrect.
Q125. Which statement about lichens is true?
- A. They cannot grow in extreme cold
- B. They serve as pollution indicators
- C. They are parasites on algae
- D. They contain only fungi
Answer: B
- A: Incorrect — lichens survive in Arctic/Antarctic.
- B: Correct — sensitive to SO₂, used as bioindicators.
- C: Incorrect — not parasitic.
- D: Incorrect. (more…)