Conservation of biodiversity - class-XI

Gene banks are a type of biorepository, which preserve genetic material. For plants, this could be by freezing cuttings from the plant, or stocking the seeds (e.g., in a seed bank). For animals, this is the freezing of sperm and eggs in zoological freezers until further need. With corals, fragments are taken which are stored in water tanks under controlled conditions.
Plant genetic material in a 'gene bank' is preserved at $-196^0$C in liquid nitrogen as mature seed (dry).

A biosphere reserve is an ecosystem with plants and animals of unusual scientific and natural interest. It is a title given by UNESCO to help protect the sites. The plan is to promote management, research and education in ecosystem conservation. This includes the 'sustainable use of natural resources'. 
In situ conservation is on-site conservation or the conservation of genetic resources in natural populations of plant or animal species, such as forest genetic resources in natural populations of tree species.

Genetic erosion is a process whereby an already limited gene pool of an endangered species of plant or animal diminishes even more, when individuals from the surviving population die off without getting a chance to meet and breed with others in their endangered low population. 

Germplasm is a term used to describe living genetic resources, such as seeds or tissue, maintained for the purpose of breeding, preservation, and other research uses. These resources may take the form of seed collections stored in seed banks, trees growing in nurseries, animal breeding lines maintained in animal breeding programs or gene banks, etc. Germplasm collections can range from collections of wild species to elite, domesticated breeding lines that have undergone extensive human selection.

Genetic diversity refers to the variety of genes within a species. Each species is made up of individuals that have their own particular genetic composition. Within a species there may also be discrete populations with distinctive genes. Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook was the first to coin the term 'speciation' for the splitting of lineages or "cladogenesis," as opposed to "anagenesis" or "phyletic evolution" occurring within lineages.
More diversity will be introduced to gene pool when speciation occurs; as a result of which more and more species will be produced.

Genetic diversity refers to the total number of genetic characteristics in the genetic makeup of the species. Genetic diversity serves as a way for populations to adapt to changing environments.
In order to capture the maximum genetic diversity of a species, recent, old, wild - all kind of varieties will be considered and taken into account and searched.
Thus, the correct answer is option (D),  'All of the above'.

Genetic erosion is a process whereby an already limited gene pool of an endangered species of plant or animal diminishes even more when individuals from the surviving population die off without getting a chance to meet and breed with others in their endangered low population. Low genetic diversity in a population of wild animals and plants leads to a further diminishing gene pool, inbreeding and a weakening immune system and fast tracks that species towards eventual extinction. 

Wild varieties of plants must be conserved because they are of utmost value to plant breeders for producing improved and favourable varieties of plants by selecting useful genes from a wide range of their wild relatives. In other words, new and improved varieties of crops are derived from their wild relatives by genetic modification. Useful traits are like high yielding, disease resistant, stress resistant etc.

Germplasm is a living tissue from which new plants can be grown. It can be a seed or another plant part like a leaf, a piece of stem, pollen or even just a few cells that can be turned into a whole plant. Germplasm contains the information for a species genetic makeup, a valuable natural resource of plant diversity. 

Vavilov worked on global genetic diversity of cultivated plants throughout his life, from which he developed several major theories that have played an important role in the development of botany, genetics and plant breeding. One such theory among several is "Theory of centres of origin of cultivated plants" (1920).

Genetic erosion is a process, whereby an already limited gene pool of an endangered species of plant or animal diminishes even more when individuals from the surviving population die off without getting a chance to meet and breed with others in their endangered low population. The term is sometimes used in a narrow sense, such as when describing the loss of particular alleles or genes, as well as being used more broadly, as when referring to the loss of varieties or even whole species.
Genetic erosion occurs because each individual organism has many unique genes which get lost when it dies without getting a chance to breed. Low genetic diversity in a population of wild animals and plants leads to a further diminishing gene pool inbreeding and a weakening immune system can then "fast track" that species towards eventual extinction.

Ecological hot spots are large areas of Earth's land surface which have high concentrations of plant endemism and also experience high rates of habitat loss. In India, 4 ecological hot spots are presently identified. The Himalayas, the Western Ghats, the Indo-Burma region and the Sundaland constitute the biodiversity hot spots in our country. One of the major features of these places is the presence of numerous endemic species.

• A biodiversity hotspot is an area which has lost at least 70 per cent of its primary native vegetation 

• It contains at least 1,500 species of vascular plants which are endemic.

• There are currently 36 recognized biodiversity hotspots.

• These are Earth’s most biologically rich yet threatened terrestrial regions.

• The hotspots provide crucial ecosystem services for human life, such as provision of clean water, pollination and climate regulation.
  

• Conservation in the hotspots promotes sustainable management of these essential natural resources and supports economic growth, which also reduces drivers of violent conflict.
  

• So, the answer is in-situ conservation.

• A biodiversity hotspot is a biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction.
• The term biodiversity hotspot specifically refers to biologically rich areas around the world that have lost at least 70 per cent of their original habitat.
• There are 34 biodiversity hot spots across the globe, among which three occur in India such as the Western Ghats & Sri Lanka, Indo-Burma (North East India) and the Himalayas.
  
• Hence Western ghats & Sri Lanka, Indo Burma and Himalaya are Hot Spots of biodiversity in India.ervo
• So, the correct answer is 'The Western Ghats & Sri Lanka, Indo Burma and Himalaya'.

Ecological hot spots are large areas of Earth's land surface which have high concentrations of plant endemism and also experience high rates of habitat loss. In India, 4 ecological hot spots are presently identified. The Himalayas, the Western Ghats, the Indo-Burma region and the Sundaland constitute the 4 biodiversity hot spots in our country. One of the major features of these places is the presence of numerous endemic species.