Biotechnology: UPSC Previous Year Questions (Science and Technology)

Explanation

Mycorrhizae is a symbiotic association between a fungus and a plant. The term ‘mycorrhiza’ refers to the role of the fungus in the plant’s rhizosphere, its root system. Mycorrhiza plays important roles in plant nutrition, soil biology and soil chemistry.

Statement 1 is correct: Trees host mycorrhizal fungus in their roots so they can absorb nutrients from the ground and resist the drought condition. These fungi exchange the carbon from the tree for vital nutrients including nitrogen, phosphate, and potassium from the soil.

Statement 2 is correct: Mycorrhizal plants can withstand unfavourable soil conditions, high pH levels, droughts, and poisonous heavy metals.

Statement 3 is correct: Mycorrhizae are symbiotic relationships between plant roots and specific soil fungi that are important for the ecosystem’s nutrient cycling and that help shield plants from environmental and cultural stress. Additionally, mycorrhizal fungi’s synthesis of oxalic acid contributes to disease suppression.

Explanation

Recombinant DNA technology entails changing genetic material outside of an organism to produce living organisms or their products with improved and desired traits. Using the appropriate vectors, this approach entails inserting DNA fragments from a number of sources that have the desired gene sequence. Manipulation in an organism’s genome is carried out either through the introduction of one or several new genes and regulatory elements or by decreasing or blocking the expression of endogenous genes through recombining genes and elements. Recombinant DNA technology, also known as genetic engineering, enables the transfer of genes across different species, including:

Across different species of plants: Genes can be transferred between various plant species to introduce desirable traits. From animals to plants: Animal genes can be introduced into plants to confer new characteristics. From microorganisms to higher organisms: Microbial genes can be inserted into higher organisms, such as plants or animals, to impart beneficial properties.