Read the given passage and answer the following questions :
The narrowly utilitarian arguments for conserving biodiversity are obvious; humans derive countless direct economic benefits from nature- food (cereals, pulses, fruits), firewood, fibre, construction material, industrial products (tannins, lubricants, dyes, resins, perfumes) and products of medicinal importance. More than 25 percent of the drugs currently sold in the market worldwide are derived from plants and 25,000 species of plants contribute to the traditional medicines used by native peoples around the world. Nobody knows how many more medicinally useful plants there are in tropical rainforests waiting to be explored. With increasing resources put into ‘bioprospecting’ (exploring molecular, genetic and species-level diversity for products of economic importance), nations endowed with rich biodiversity can expect to reap enormous benefits. The broadly utilitarian argument says that biodiversity plays a major role in many ecosystem services that nature provides. The fast-dwindling Amazon forest is estimated to produce, through photosynthesis, 20 per cent of the total oxygen in the earth’s atmosphere. Pollination (without which plants cannot give us fruits or seeds) is another service, ecosystems provide through pollinators layer – bees, bumblebees, birds and bats. There are other intangible benefits – that we derive from nature–the aesthetic pleasures of walking through thick woods, watching spring flowers in full bloom or waking up to a bulbul’s song in the morning. The ethical argument for conserving biodiversity relates to what we owe to millions of plant, animal and microbe species with whom we share this planet. Philosophically or spiritually, we need to realise that every species has an intrinsic value, even if it may not be of current or any economic value to us.
Read the following statements about ex situ conservation:
A. Threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care.
B. Seeds of different genetic strains of commercially important plants can be kept for long periods in seed banks.
C. Plants can be propagated using tissue culture methods.
D. Gametes of threatened species can be preserved in viable and fertile condition for long periods in seed banks.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A, B and C only
In ex situ (off-site) conservation, threatened plants and animals, or their gametes, seeds and tissues, are kept and cared for outside their natural habitat. The book names zoological parks, botanical gardens, cryopreservation, in vitro fertilisation, tissue culture and seed banks.
A. Threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care. — True. This is the meaning of ex situ conservation; zoological parks, botanical gardens and wildlife safari parks serve this purpose.
B. Seeds of different genetic strains of commercially important plants can be kept for long periods in seed banks. — True. Seed banks store seeds of different genetic strains of commercially important plants for long periods.
C. Plants can be propagated using tissue culture methods. — True. Tissue culture is one of the newer ex situ methods for propagating plants.
D. Gametes of threatened species can be preserved in viable and fertile condition for long periods in seed banks. — False. Gametes are preserved for long periods by cryopreservation techniques. Seed banks store seeds, not gametes.
NCERT Extract:
How do we Conserve Biodiversity? – “… Ex situ Conservation– In this approach, threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care. Zoological parks, botanical gardens and wildlife safari parks serve this purpose. … In recent years ex situ conservation has advanced beyond keeping threatened species in enclosures. Now gametes of threatened species can be preserved in viable and fertile condition for long periods using cryopreservation techniques, eggs can be fertilised in vitro, and plants can be propagated using tissue culture methods. Seeds of different genetic strains of commercially important plants can be kept for long periods in seed banks.”