13 public questions tagged with this topic.
r-selected species focus on rapid reproduction and minimal parental care, unlike K-selected species.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Parasitism and Commensalism
r-selected species typically have small body sizes, high reproductive rates, and little parental care.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Parasitism and Commensalism
K-selected species invest in high parental care, ensuring the survival of fewer but more competitive offspring.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Competition - Competitive Exclusion
r-selected species, like bacteria, reproduce rapidly with minimal parental care.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Life History Variations and Population Interactions - Overview
r-selected species, such as bacteria, reproduce quickly and produce many offspring with little parental care.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Attributes - Birth Death Sex Ratio Age Distribution
r-selected species reproduce rapidly, producing many offspring with little or no parental care.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Adaptations - Morphological Physiological Behavioural
r-selected species, like bacteria, reproduce rapidly with little parental care, while K-selected species, like elephants and whales, have slower reproduction.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Responses to Abiotic Factors - Regulate Conform Migrate Suspend
Rats exhibit an r-selected strategy, characterized by high reproductive rates, small body size, and minimal parental care.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Responses to Abiotic Factors - Regulate Conform Migrate Suspend
r-selected species reproduce quickly, grow rapidly, and do not exhibit delayed reproduction.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Organism and Environment - Major Biomes Abiotic Factors
“Density-independent” for in r-selected species, mortality is. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. 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. The remaining alternatives—“Density-dependent”, “Late-life driven”, “Genetically fixed”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Survivorship curves summarize age-specific mortality: Type I concentrates loss late in life, Type II approximates a constant hazard, and Type III concentrates loss early. They are empirical patterns, not rigid taxonomic rules. 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: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 12
“r-selected species” for in r-k selection, high reproductive rate and short lifespan are features of. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. 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. The remaining alternatives—“K-selected species”, “S-selected species”, “Ruderals”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Survivorship curves summarize age-specific mortality: Type I concentrates loss late in life, Type II approximates a constant hazard, and Type III concentrates loss early. They are empirical patterns, not rigid taxonomic rules. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit. Linking the wording to measurable consequences for fitness, abundance, or flux gives the conclusion its scientific meaning and prevents a purely mnemonic interpretation.
Ref: Plant Strategies and Vegetation Processes, Grime, 2nd Ed.
The keyed exception is “Strong density-dependent mortality.” In the context of which of the following traits is not characteristic of r-selected tree species, that statement differs from the governing ecological pattern and must be evaluated against the mechanism rather than accepted from wording alone. Interpretation must distinguish absolute population change from a per-capita rate and must state the time interval and population boundary. Age structure, dispersal, environmental variation, and delayed responses can all make observed trajectories depart from a simple model. The remaining alternatives—“High colonization capability”, “Thrive in ephemeral habitats”, “Low resource competition”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Mechanistic support comes from showing how resource limitation, enemies, mate availability, or physiological stress changes demographic performance. A descriptive association alone does not establish regulation or causation. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.
Ref: Campbell Biology, Urry et al., 12th Ed., Unit 8 Ecology
