4 public questions tagged with this topic.
Plants account for about 22% of all described species, whereas animals constitute more than 70%.
Ref: NCERT Class 12 Biology Chapter 13: Biodiversity and Conservation Patterns of Biodiversity - Latitudinal Gradients
Gynodioecious breeding system populations consist of two distinct plant types female individuals producing only pistillate flowers lacking stamens and hermaphrodite individuals producing bisexual flowers with both whorls, maintained by interplay of nuclear genes and cytoplasmic male sterility. Contrasts with androdioecious male plus hermaphrodite, monoecious both sexes on same plant, and solely bisexual homogeneously. Gynodioecy enhances outcrossing because females are obligately outcrossed, hermaphrodites may self but suffer inbreeding depression. Examples include Thymus vulgaris, Fragaria vesca biotypes and Silene acaulis. Female frequency reflects balancing selection involving pollen limitation and seed fitness advantage.
Ref: Richards, Plant Breeding Systems; Campbell Biology, Gynodioecy evolution male sterility
“Lantana camara” for which species is known for its allelopathic properties. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Ecological interpretation requires separating the immediate process from its broader consequence. A mechanism operating through physiology or behavior can scale up to alter survival, reproduction, abundance, distribution, and community structure. The remaining alternatives—“Eichhornia crassipes”, “Parthenium hysterophorus”, “Tabebuia rosea”—refer to different states, processes, or scales and therefore do not express the same causal relationship. The inference is strongest when the relevant variables, spatial boundary, and time scale are explicit. Context can alter the magnitude of an effect without changing the definition of the focal concept. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors.
Ref: NCERT Biology Class 12, Ch. 15 Biodiversity and Conservation
“Elephant” for which species likely shows all three extremes: growth, survival, fecundity. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Selection favors the schedule that increases lifetime reproductive success under local mortality and resource conditions. Body size, development time, fecundity, parental investment, and generation length consequently tend to covary. The remaining alternatives—“Annual grass”, “Banana”, “None”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Life-history traits reflect allocation among growth, maintenance, survival, and reproduction. Energy invested in many offspring cannot simultaneously be invested in large offspring, prolonged care, or future breeding, creating measurable trade-offs. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation. Field observations could test this account by measuring the proposed driver and the demographic or ecosystem response while controlling plausible confounding factors.
Ref: Plant Strategies and Vegetation Processes, Grime, 2nd Ed.
