Indian Biodiversity - Flora

Pair I – Cassava: Woody shrub → Correct Cassava (also called tapioca or manioc) is indeed a woody shrub cultivated for its starchy tuberous roots.

Pair II – Ginger: Herb with pseudostem → Correct Ginger is a herbaceous perennial with a pseudostem formed by leaf sheaths; the edible part is the rhizome.

Pair III – Malabar spinach: Herbaceous climber → Correct Malabar spinach (Basella alba) is a soft, herbaceous twining climber, commonly grown as a leafy vegetable.

Pair IV – Mint: Annual shrub → Incorrect Mint (Mentha spp.) is not a shrub; it is a perennial herb with soft stems, spreading by stolons.

Pair V – Papaya: Woody shrub → Incorrect Papaya (Carica papaya) is a herbaceous tree (giant herb), not a woody shrub—it has a soft, hollow stem.

Out of the listed plants, the following are nitrogen-fixing plants: 1. Alfalfa 3. Chickpea 4. Clover These plants have a symbiotic relationship with bacteria called rhizobia. The bacteria colonize nodules in the plant's roots and fix atmospheric nitrogen into a usable form (nitrates) that the plant can absorb.


The other options are not nitrogen-fixing plants: 2. Amaranth 5. Purslane (Kulfa) 6. Spinach These plants require nitrogen from the soil but cannot fix it themselves. They rely on soil nitrogen content or applied fertilizers. Remember: Purslane is a weed. If you would have known this piece of information, the question could have been easily solved by simple elimination.

Therefore, the correct answer is (1, 3, 4).

* The Himalayan nettle, also known as Girardinia diversifolia, is a plant species native to the Himalayan regions of India, Nepal, and parts of China. It grows at high altitudes and is known for its long fibres that can be extracted from the stem.

* These fibres are some of the longest in the plant world and are used in the production of textiles.

* Therefore, the Himalayan nettle is found to be a sustainable source of textile fibre.

* Prosopis juliflora, commonly known as mesquite or thorn mimosa, frequently appears in discussions about invasive species due to its significant impact on ecosystems and biodiversity.

* Originally native to Central and South America, Prosopis juliflora was introduced to various parts of Africa, Asia, and Australia for purposes like afforestation, erosion control, and fuelwood supply.

* However, due to its rapid growth rate, tolerance for harsh conditions, and prolific seed production, it can become invasive.

* It can outcompete native plants, disrupt ecological balances, and form dense thickets that hinder other vegetation growth.

* In states like Tamil Nadu, Prosopis juliflora has been labelled an invasive species causing ecological damage. Efforts are underway to remove it from certain areas to restore native ecosystems.

Statement 1 is correct. Red Sanders, also known as Red Sandalwood or Pterocarpus santalinus, is indeed a tree species native to the southern Eastern Ghats mountain range of India.

Statement 2 is incorrect. It is one of the most important trees in the tropical rainforest areas of South India. Red Sanders is not typically found in tropical rainforests. It grows in drier semi-arid regions of the Eastern Ghats.

Statement 1 is correct: Neem oil is a well-known natural pesticide and has been shown to be effective in controlling some insect and mite populations.

Statement 2 is incorrect: While there might be some research into using neem seeds for biofuels, it's not a widespread application in 2014 when the question was asked by the UPSC. Hospital detergents typically use stronger and more regulated chemicals.

Statement 3 is correct: Neem oil does have applications in the pharmaceutical industry. It has been used in traditional medicine for centuries, and some of its properties are being explored in modern medicine for their anti-bacterial, anti-inflammatory, and other potential benefits.