5 public questions tagged with this topic.
A population consists of individuals of the same species inhabiting a particular area, sharing resources, and interbreeding.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Mutualism and Amensalism
A bell-shaped age pyramid indicates a stable population with birth and death rates in balance.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Attributes - Birth Death Sex Ratio Age Distribution
Balancing selection reflects key principle in quiz on section e solved pyqs, where evolutionary mechanisms shape genetic variation and adaptation. In this context, Balancing selection aligns with experimental and theoretical evidence from population genetics, behavioral ecology and molecular phylogeny. Textbooks like Campbell Biology, Futuyma Evolution and Hartl Principles illustrate supporting data. Understanding why Balancing selection fits helps integrate natural selection, environment.
Ref: Futuyma, Evolution, Variation, Drift, and Speciation Concepts.
In ecology and population genetics, population represents group of individuals belonging to single species occupying same geographic area and time interval, capable of interbreeding and sharing gene pool. It is not simply assemblage of different species or random collection; it implies reproductive interaction, common gene exchange, and similar selective pressures. Population size, density, age structure, and gene frequencies change over generations due to evolution. Understanding population concept underlies Hardy-Weinberg law, genetic drift, migration, and conservation genetics, where allele dynamics track within species-specific groupings.
Ref: Hartl & Clark, Principles of Population Genetics, 4th ed., Chapter 1: Population Definition; Griffiths, Chapter 20
Clumped dispersion occurs when individuals are concentrated in groups or habitat patches rather than spaced independently or evenly. It is the most common broad pattern in nature because resources such as water, nutrients, shelters, hosts, or breeding sites are often spatially heterogeneous. Limited dispersal can keep offspring near parents, and social processes such as flocking, schooling, colony formation, or cooperative defense can further promote aggregation. In quadrat data, clumping typically produces variance greater than the mean: many units contain few or no individuals, while a small number contain high counts. Random dispersion has variance near the mean and arises when positions are independent; uniform dispersion has variance below the mean and reflects repulsion or regular spacing. “Mixed” is not a standard primary category for this diagnostic. A clumped pattern does not necessarily mean direct attraction among organisms, because all individuals may independently select the same favorable patches. Determining mechanism therefore requires environmental and behavioral evidence in addition to the observed spatial distribution.
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 9
