4 public questions tagged with this topic.
Thorns are a morphological defense that protect plants from herbivores by deterring feeding.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Predation and Herbivory
Associational resistance occurs when a plant suffers less herbivory because of the identity, abundance, or arrangement of neighboring plants. An unpalatable or chemically defended neighbor may mask host odors, visually conceal the focal plant, repel herbivores, reduce landing probability, or support predators and parasitoids that attack herbivores. The protected plant need not possess the neighbor’s defensive compound; reduced damage emerges from community context. This differs from chemical defense produced by the focal plant itself and from camouflage based solely on matching an abiotic background. It is also not necessarily mimicry, because the focal plant need not evolve resemblance to the unpalatable species. Associational effects can reverse: a highly attractive neighbor may concentrate herbivores and produce associational susceptibility, or a shared herbivore may spill over between hosts. Experiments test the mechanism by manipulating neighborhood composition while controlling focal plant density and measuring herbivore arrival or damage. The concept therefore demonstrates that plant resistance is partly an emergent property of local vegetation, not only an intrinsic trait of individual plants.
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 8-13
Go with B — Analgesic. Under Phytohormone ALL, this is the standard explanation you’d use in class: it names the real driver or definition, while the rest are nearby but wrong. Not these: A) Growth promoter; C) Ethylene inhibitor; D) Auxin analog. When two options sound similar, choose the one that matches the textbook definition most tightly.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.
Answer: B) UV radiation. For PLANT SEC METABOLITES, remember the key idea and you’ll land on this option; the distractors usually swap cause and effect or confuse similar terms. Avoid: A) Herbivores; C) Pathogens; D) Salinity. Name the process first, then pick the option that describes it — don’t reverse cause and effect.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.
