Biology · Biodiversity and Conservation · NEET
It is WITHIN a single species. Genetic diversity means one species shows genetic variation over its range. All three NCERT examples are single species: Rauwolfia vomitoria is one species, rice (Oryza sativa) is one species, and mango (Mangifera indica) is one species. The many strains or varieties are all the SAME species with different genes. Variation BETWEEN different species is species diversity, not genetic diversity.
Because the plant Rauwolfia vomitoria growing in different Himalayan ranges has genetic variation. NCERT says this variation shows up as differences in the potency and concentration of the active chemical reserpine that the plant produces. Same species, but the genes differ across its distributional range, so the medicinal chemical output differs. This is the textbook proof of genetic diversity.
NCERT states India has more than 50,000 genetically different strains of rice and 1,000 varieties of mango. Learn these exact numbers: 50,000 rice, 1,000 mango. These are examples of genetic diversity because all the strains are one species of rice and all the varieties are one species of mango - the difference is in their genes.
Rauwolfia vomitoria, a medicinal plant that grows in different Himalayan ranges. Its active chemical is reserpine (used to lower blood pressure). Remember the pairing: Rauwolfia goes with genetic diversity and reserpine. Do not confuse it with the Western Ghats amphibians, which is the example for species diversity.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Genetic diversity is the difference in genes found within one single species over the area where it lives. The species stays the same, but individuals or populations carry different genes.
Reserpine. NCERT says the genetic variation in Rauwolfia vomitoria across the Himalayan ranges shows up as differences in the potency and concentration of reserpine.
Genetic diversity. All 50,000 strains belong to the same species of rice; only their genes differ. Different species would be needed for species diversity.
A strain or variety is a genetically different group within the SAME species (genetic diversity). A species is a distinct kind of organism. Rice strains and mango varieties are within-species, so they show genetic diversity, not species diversity.
NCERT lists it as the first of the three levels of biodiversity, and NTA often asks you to match the correct example (Rauwolfia, rice, mango) to the correct level. Getting the level right earns easy marks.
