22 public questions tagged with this topic.
Gymnosperms do not produce flowers; flowers are a characteristic feature of angiosperms.
Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Gymnosperms - Characteristics and Life Cycle
Not all pteridophytes have macrophylls; some, like Selaginella, have small microphylls.
Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Pteridophytes - Structure and Life Cycle
In some pteridophytes like Selaginella and Equisetum, sporophylls form strobili or cones.
Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Pteridophytes - Structure and Life Cycle
Liverworts, such as Marchantia, reproduce asexually through specialized structures called gemma cups, which are absent in mosses.
Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Bryophytes - Liverworts and Mosses
Fungi are heterotrophic organisms, whereas green plants are autotrophic. Their cell walls also differ: fungal walls contain chitin, while plant cell walls are mainly cellulosic. These differences support their placement in separate kingdoms.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Five Kingdom Classification and Kingdom Plantae Animalia
Wheat is Triticum aestivum. It belongs to the genus Triticum, family Poaceae and order Poales.
Ref: NCERT Class 11 Biology Chapter 1: The Living World Taxonomical Aids - Zoological Parks and Keys
Mango is Mangifera indica. It belongs to the genus Mangifera, family Anacardiaceae and order Sapindales.
Ref: NCERT Class 11 Biology Chapter 1: The Living World Taxonomical Aids - Herbarium and Botanical Gardens
Coconut is classified as a drupe, with a fibrous mesocarp and a hard endocarp.
Ref: NCERT Class 11 Biology chapter - Morphology of flowering plants
In contemporary taxonomy, bryophytes are properly split into three distinct monophyletic phyla reflecting deep Precambrian divergences: Bryophyta includes true mosses, Hepatophyta or Marchantiophyta includes liverworts characterized by dorsiventral thalli, unicellular smooth or pegged rhizoids, absence of stomata on gametophyte and presence of membrane-bound oil bodies with terpenes, and Anthocerotophyta hornworts with unique sporophyte intercalary meristem. Pteridophyta is vascular seedless group belonging to tracheophytes. Recognizing Hepatophyta as liverwort lineage clarifies placement of genera Riccia, Marchantia and leafy Jungermanniales with incubous leaves.
Ref: Crandall-Stotler et al 2009 Hepatophyta classification; Goffinet Bryophyte Biology
Tracheophytes including pteridophytes, gymnosperms and angiosperms all contain lignified xylem tracheary elements with bordered pits facilitating efficient long-distance water transport under negative pressure and structural support enabling tall upright growth independent of turgor. Nonvascular plants lack true lignified xylem and phloem, instead possess hydroids lacking lignin and leptoids for conduction plus external capillary action, limiting size to few centimeters. Bryophytes constitute sole recognized extant group occupying nonvascular grade. Classifying bryophytes as nonvascular aligns with morphology, life cycle dominance, and molecular phylogeny distinguishing basal land plants.
Ref: Vanderpoorten & Goffinet Bryophyte Biology 2nd ed.; Campbell Ch 29: Nonvascular
Pteridophytes combine traits morphologically intermediate between bryophytes and spermatophytes illustrating evolutionary transition. Unlike non-vascular bryophytes lacking xylem lignification and true organs, they possess true tracheids with lignin, phloem sieve elements, enabling vertical growth and homoiohydry. Unlike gymnosperms and angiosperms forming seeds via heterospory plus integumented megasporangium and pollen, they remain seedless reproducing via free spores requiring external water for fertilization. Therefore botanical description as seedless vascular plants accurately captures vascular organization without seed habit, including ferns, horsetails, clubmosses and whisk ferns.
Ref: NCERT Class 11 Biology Ch 3: Pteridophytes; Campbell 12th Ch 30: Seedless vascular
Spermatophytes include all seed-bearing vascular plants derived from progymnosperm ancestors late Devonian about 385 million years ago, characterized by megasporangium retained and integumented forming ovule that after fertilization matures into seed containing diploid embryo, stored nutrients haploid triploid and protective testa derived from integuments. This lineage encompasses Gymnospermae naked seeds and Angiospermae enclosed seeds within fruits, surpassing bryophytes lacking true vascular tissue xylem phloem and pteridophytes homosporous spore-dispersed lacking seed habit protected embryo. Term Thallophyte obsolete grouping algae fungi lichens undifferentiated thallus lacking roots stems. Spermatophyte dominance stems from embryo protection dispersal capacity dormancy.
Ref: NCERT Class 11 Biology, Chapter 3: Spermatophytes seed plants gymnosperms angiosperms definition
