• (a) (i)  Narrowly utilitarian - related examples like derive economic benefits from nature food (cereals, pulses, fruits) / firewood / fibre / construction materials / industrial products (tannins, Iubricants, dice, resins, perfumes) / product of medicinal importance / drugs.
• Broadly utilitarian - 20% of total O₂ from Amazon forests / pollination / aesthetic pleasures. 
• Ethical - millions of species (plants, animals, microbes) share this planet / we need to realise that every species has an intrinsic value (even if it may not current or any economic value to us) / we have a moral duty to care for their well being and pass on our biological legacy to future generations.
• (ii) In situ conservation / biosphere reserves/ national parks / sanctuaries / sacred groves.
• Ex situ conservation / zoological parks / botanical gardens i wild life safari parks / cryopreservation / seed banks / tissue culture (eggs in vitro) 

(b) Hot spots : regions with high level of species richness, high degree of endemism. 

Sacred groves : tracts of forest containing tree / wild life were venerated and given total protection // to protect last refuses for a large number of rare, and threatened plants.

Detailed Answer:

(a) We should conserve bio-diversity because of the following reasons : 

(i) Humans derive countless economic benefits from nature like 

(1) Food (cereals, pulses, fruits) 

(2) Wood, fibre, construction material, industrial products (tannins, lubricants, dyes, resins, perfumes) and 

(3) Products of medicinal importance.

(ii) Biodiversity plays a major role in many ecosystem services that nature provides. Such as production of oxygen and pollination. 

(iii) It is our moral duty to care for well being and pass on our biological legacy in good order to future generations. 

We can conserve biodiversity by following ways : 

(i) In situ conservation : It is the conservation of genetic resources within natural or human-made ecosystems in which they occur. e.g., protected areas such as national parks, sanctuaries, biosphere reserves, cultural landscapes, natural monuments. 

(ii) Ex situ conservation (off site) : It is the conservation of organisms outside their habitats, e.g., genetic resource centres, zoological parks, botanical gardens, gene banks, etc. 

(b) Biodiversity hotspots and sacred groves are the regions that are rich in biodiversity. A system with greater biodiversity is more stable and has greater productivity. Hence, biodiversity is related with overall health of our ecosystem and the survival of human race on the earth.