#spores

BOTANY

Which of the following pteridophytes produces both microspores and megaspores?

Salvinia is a heterosporous pteridophyte that produces both microspores (male) and megaspores (female). This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Biology Textbook - Latest Edition for Academic Session 2026-27 (Botany section, Rationalized Textbook for Class XI and XII), Chapter: Biology - Botany portion (Latest NCERT Textbooks for Academic Session 2026-27 -

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Dictyostelium

Dictyostelium fruiting bodies primarily consist of:

Mature sorocarps consist of two cell types with opposite fates. Prestalk cells, after depositing cellulose tube, swell vacuoles, synthesize thick walls, and die, forming rigid stalk that supports sorus above substratum. Dead stalk provides mechanical strength and prevents desiccation without competing for germination resources. Spores remain alive, encapsulated, dehydrated, containing trehalose and heat-shock proteins for longevity. Structure composed of live stalk plus spores would collapse and consume nutrients. Therefore stalk sacrifice representing altruism illustrates kin selection where

Ref: Principles of Development, Lewis Wolpert, Chapter 3: Dictyostelium fruiting body - altruistic stalk cell death.

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Angiosperms and Plant Life Cycles - Alternation of Generations

Which term describes the direct development of a new plant from a vegetative cell without spore formation?

Apospory is the formation of a gametophyte directly from sporophytic cells without spore formation.

Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Angiosperms and Plant Life Cycles - Alternation of Generations

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Pteridophytes - Structure and Life Cycle

Which of the following pteridophytes produces two types of spores (heterospory)?

Selaginella is a heterosporous pteridophyte, producing both microspores and megaspores.

Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Pteridophytes - Structure and Life Cycle

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Pteridophytes - Structure and Life Cycle

Which type of spores are produced by homosporous pteridophytes?

Homosporous pteridophytes produce spores that are morphologically similar but may develop into bisexual gametophytes.

Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Pteridophytes - Structure and Life Cycle

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Five Kingdom Classification and Kingdom Plantae Animalia

A plant life cycle alternates between a diploid phase that produces spores and a haploid phase that produces gametes. Wh

The diploid sporophytic phase and the haploid gametophytic phase alternate in plant life cycles. Their relative duration and dependence vary among different plant groups.

Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Five Kingdom Classification and Kingdom Plantae Animalia

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Protista - Euglenoids Slime Moulds Protozoans

Which statement correctly describes the spores of slime moulds?

Slime-mould spores possess true walls, are extremely resistant and can survive for many years under adverse conditions. They are dispersed by air currents.

Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Euglenoids Slime Moulds Protozoans

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Bacteria - Structure and Economic Importance

What may some bacteria produce under unfavourable conditions?

Bacteria reproduce mainly by fission, but under unfavourable conditions some of them produce spores. These spores help them persist when environmental conditions are unsuitable.

Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Bacteria - Structure and Economic Importance

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Bacteria - Structure and Economic Importance

Bacteria normally reproduce by fission. Under different circumstances, some form spores while others transfer DNA betwee

Bacteria reproduce mainly by fission. Some produce spores under unfavourable conditions, while a primitive type of sexual reproduction may occur through the transfer of DNA from one bacterial cell to another.

Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Bacteria - Structure and Economic Importance

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Bacteria - Structure and Economic Importance

Bacteria normally reproduce by fission, but two additional observations are made: some form spores during adverse condit

Bacteria reproduce mainly by fission. Under unfavourable conditions, some produce spores, while a primitive type of sexual reproduction may occur through the transfer of DNA from one bacterial cell to another.

Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Bacteria - Structure and Economic Importance

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Kingdom Monera - Archaebacteria and Eubacteria

A fungus has branched, septate mycelium, generally lacks asexual spores and forms four spores externally after karyogamy

The features identify a Basidiomycete. Karyogamy and meiosis occur in the basidium, generally producing four basidiospores externally. The basidia are arranged in fruiting bodies called basidiocarps.

Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Kingdom Monera - Archaebacteria and Eubacteria

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Plant Classification

Thick spore walls in land plants mainly protect against

Land plant spores possess complex wall stratification including innermost intine cellulosic, middle exine rich in chemically inert sporopollenin highly resistant polymer derived from lipid metabolism, and outer perispore. Primary adaptive value involves preventing desiccation during prolonged airborne dispersal across dry air, fluctuating humidity and high temperatures, maintaining protoplast viability until germination on moist substrate. While sporopollenin confers resistance against pathogens, chemical degradation and UV, desiccation resistance drives major selection. Herbivory and mechanic

Ref: Wellman et al. Sporopollenin wall, J Micropalaeontology; Campbell Ch 29: Spore

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