Q.59
Genetics & Plant Breeding - ICAR JRF/SRF 2024
MCQ (Single Correct) +4 −1
Van Valen's (1976) Ecological species concept explains that a species taxon as a lineage of organisms is maintained and segmented by ecological forces. Accordingly, the species integrity is maintained by:
  • Van Valen's Ecological Species Concept (1976): Leigh Van Valen defined a species as a lineage (an ancestral-descendant sequence of populations) that occupies an adaptive zone minimally different from that of any other lineage in its range and evolves separately from all lineages outside its range.
  • Mechanism of Maintenance: The cohesive integrity of the lineage is maintained primarily by stabilizing ecological selection, while disruptive selection driving ecological divergence into distinct niches leads to the formation of new species. (Correct answer: Option 1)
Explanation not matching this question? क्या व्याख्या इस प्रश्न से मेल नहीं खा रही? Report
Want to practice this paper in exam conditions? क्या आप परीक्षा जैसे माहौल में अभ्यास करना चाहते हैं? Test yourself in 5-question batch format with timer and hidden answers. 5-प्रश्नों के बैच फॉर्मैट, टाइमर और छिपे उत्तरों के साथ खुद को परखें।
Start Practice Mode → प्रैक्टिस टेस्ट मोड शुरू करें →

Genetics & Plant Breeding Subjects

Browse all chapters by subject

Official PYQ Papers

Previous Year Papers of Genetics & Plant Breeding

Practice official shift-wise question papers with answer keys and detailed explanations on the actual exam pattern.

1
Total Available Previous Papers

Choose Exam

Exam Directory

Browse official Previous papers and mock tests

10 Major Agriculture Exams Available