5 public questions tagged with this topic.
The competitive exclusion principle states that two species cannot coexist indefinitely if they compete for the same limiting resource.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Competition - Competitive Exclusion
In predation, the predator benefits while the prey is harmed or killed.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Predation and Herbivory
Predation helps regulate prey populations and maintain ecological balance, preventing overpopulation.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Responses to Abiotic Factors - Regulate Conform Migrate Suspend
Several biophysical methods probe protein interactions, but only Förster Resonance Energy Transfer exhibits steep distance dependence in 1-10 nanometer range. Efficiency proportional to inverse sixth power of separation imposes strict proximity requirement; beyond approximately 10 nm efficiency becomes negligible. SPR detects refractive index changes at surface, not molecular ruler scale; phage display selects binders; Co-IP isolates complexes regardless of distance. FRET therefore serves as spectroscopic ruler for conformational changes, domain interactions, and complex assembly within macromolecular dimensions near Förster radius.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
In social-evolution terminology, spite describes an action that imposes a fitness cost on both the actor and the recipient. Its direct payoff is therefore (−, −), unlike altruism, which costs the actor but benefits the recipient, or mutualism, which benefits both. Spite can evolve only under restricted conditions because an allele that simply harms its bearer should be eliminated. Indirect fitness can make such behavior favorable when harm is directed preferentially toward individuals less related than the population average and thereby benefits the actor’s relatives through reduced competition. Limited dispersal, kin discrimination, or “green-beard” recognition can create this assortment. Competition also often reduces both participants’ performance, but it is a broad ecological interaction rather than a social act defined by actor and recipient consequences. Examples proposed as spite must distinguish genuine costly harm from selfish interference that provides the actor an immediate resource benefit. Hamilton’s rule can be extended using negative relatedness to explain when recipient harm compensates for the actor’s cost through inclusive-fitness effects.
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 8-13
