Tag: biodiversity: conservation
Questions Related to biodiversity: conservation
Wild varieties of plants must be conserved to
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Destroy ecosystem
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Feeding wild animals
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Future evolution
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Incorporate useful traits in future crop varieties
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 present in
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Somatic cells
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Growing points
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Reproductive cells
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Both (a) and (c)
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.
Cryopreservation is carried out at
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-10 to -20$^{0}$C
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-50 to -60$^{0}$C
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-196$^{0}$C
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-100$^{0}$C
Virus-free clones are obtained from
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Callus
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Embryoids
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Haploid culture
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Shoot tip culture
Shoot tip culture is the culture of terminal part of shoot to a plant in in-vitro condition or in lab called as shoot tip culture. Mostly the shoot tip culture used for obtain disease free plant without genetically changes. The plant which affected by any contaminant mostly by viruses have saved by shoot tip culture, because shoot tip of any affected plant is less or free from contamination (viruses, bacteria, fungus).
Dwarf variety of wheat was developed by
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M.S. Swaminathan
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Vavilov
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Borlaug
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Both A and C
Norman Borlaug developed a special breed of dwarf wheat that resisted a wide spectrum of plant pests and diseases and produced two to three times more grain than the traditional varieties. During the period from 1949-55, M S Swaminathan undertook research on potato, wheat, rice and jute genetics, after which he worked on Mexican dwarf wheat varieties.
The concept of "Centres of Origin of Cultivated Plants" was put forward by
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Swaminathan
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Mendel
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Vavilov
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Borlaug
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).
Genomic DNA library is
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Packing of donor DNA in a collection of vectors.
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A collection of gene vectors.
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Collection of organisms for extracting DNA.
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A collection of literature about DNA.
A genomic library is a collection of total genomic DNA from a single organism. This DNA is packed in a population of identical vectors for storage. Each vector contains a different insert of DNA.
Gene library consists of
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All fragments of a genome
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Frozen germplasm
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Tissue culture
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Living bacteria having clones of genes
A gene library can be defined as a collection of living bacteria colonies that have been transformed with different pieces of DNA from the organism. These DNA fragments are the sources of the genes of interest.
Genetic erosion is
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Deforestation
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Shifting cultivation
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Adopting genetically uniform varieties
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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. 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.
Vavilov collected............. varieties of Wheat
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26,000
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2,600
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4,600
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260
Vavilov collected not less than 26,000 varieties of wheat alone, were kept in cultivation at Leningrad. These collections formed the basis for new theories on the origin of cultivated plants and laid the foundation for the future improvement of crop plants and of one of the largest and oldest seed banks in the world today.