Agricultural And Environmental Biotechnology

The Bt-brinjal is a genetically modified form of the traditional brinjal. The 'Bt' in Bt-brinjal stands for Bacillus thuringiensis, a bacterium that naturally produces a toxin that is harmful to certain pests. The gene from this bacterium is inserted into the brinjal, making it resistant to certain pests. This modification does not aim to improve its taste, make it drought-resistant, or extend its shelf-life. Therefore, the primary objective of developing Bt-brinjal is to make it pest-resistant.

**Statement 1 is correct:** UV radiation can effectively inactivate or kill various harmful microorganisms, such as bacteria, viruses, and protozoa, by damaging their genetic material. This makes it an effective method for disinfecting water and eliminating waterborne pathogens. **Statement 2 is incorrect:** UV radiation does not directly remove undesirable odours from water. Odour removal from water typically involves other treatment processes, such as activated carbon filtration, aeration, or chemical treatment. **Statement 3 is incorrect:** UV radiation does not have a direct effect on the sedimentation of solid particles, removal of turbidity, or improving the clarity of water. These aspects are typically addressed by other physical and chemical water treatment processes, such as coagulation, flocculation, and filtration.

Biopesticides are certain types of pesticides derived from natural materials such as animals, plants, bacteria, and certain minerals. Bacteria, fungi, and flowering plants all have species that are used as biopesticides. Bacteria like Bacillus thuringiensis produce proteins that are toxic to certain insects. Fungi can also be used as biopesticides as they can infect and kill insects. Flowering plants can produce compounds that are toxic to certain pests and can be used as biopesticides.

Statement 1 is incorrect: Bt brinjal is created by inserting a gene from a soil bacterium called Bacillus thuringiensis (Bt), not a fungus. Specifically, the Cry1Ac gene is used to provide resistance against the Brinjal Fruit and Shoot Borer (BFSB). Statement 2 is incorrect: Bt brinjal seeds are not "terminator seeds." While the developer (Mahyco) holds the intellectual property rights, the technology itself does not include a Genetic Use Restriction Technology (GURT) that prevents seeds from being reused. However, like many hybrids, the yield might decrease in subsequent generations, leading farmers to prefer buying new seeds. Statement 3 is correct: A major point of resistance from activists and health experts is the lack of long-term independent studies on human health. Apprehensions include potential allergenicity and changes in the nutritional profile. Statement 4 is correct: India is a center of origin and diversity for brinjal. Critics argue that cross-pollination between Bt brinjal and wild/local varieties could lead to genetic contamination, potentially wiping out indigenous biodiversity.

Lead is a toxic metal that can cause serious health problems if ingested or inhaled. It is found in various sources, even after its addition to petrol has been banned. Smelting units are one of the significant sources of lead exposure. During the smelting process, lead is released into the environment, which can be inhaled or ingested. Paints, especially those used in older houses, can contain lead. When the paint peels or cracks, lead dust can be released into the environment. However, pens and pencils, as well as hair oils and cosmetics, are not typically sources of lead poisoning. Therefore, the correct answer includes smelting units and paints.

Root hairs are extremely delicate, whether on a tree or a seedling. When transplanting young trees from a nursery to a woodland, damage to the roots and root hairs often leads to the death of a tree.

Aflatoxins are poisonous carcinogens that are produced by certain moulds (Aspergillus flavus and Aspergillus parasiticus), which grow in soil, decaying vegetation, hay, and grain.

**Statement 1 is correct:** Mycorrhizae: - Greatly increase the effective root surface area - Improve water absorption - Help plants withstand drought stress **Statement 2 is correct:** Mycorrhizal fungi help plants: - Grow in acidic or alkaline soils - Access nutrients even when pH reduces their availability **Statement 3 is correct:** Mycorrhizae offer bioprotection: - Compete with soil pathogens - Produce antibiotics - Strengthen plant immune responses

Fruits remain biologically active even after harvesting. They continue to undergo respiration, a metabolic process in which stored sugars are broken down to release energy. This respiration accelerates ripening and eventual spoilage. Cold storage works primarily by lowering temperature, which slows down enzymatic and metabolic processes inside the fruit. As temperature decreases, the rate of respiration decreases, delaying ripening and reducing microbial activity. This significantly increases the storage life of fruits.

A transgenic crop is a genetically modified organism (GMO). Transgenic indicates that a transfer of genes has occurred using recombinant DNA technology. Generally, a transgenic crop contains one or more genes that have been inserted artificially either from an unrelated plant or from different species altogether. **Technique 1 is incorrect:** Budding and grafting in fruit plants does not include genetic editing or modification. Thus, option 1 is eliminated. **Technique 2 is correct:** Cytoplasmic male sterility (CMS) is a condition where plants cannot produce viable pollen. It is typically controlled by genes in the cytoplasm. While CMS can occur naturally, it can also be introduced or manipulated using genetic engineering techniques to create transgenic lines for more efficient hybrid seed production. **Technique 3 is correct:** Gene silencing technique uses engineered genetic material to specifically suppress the expression of certain genes in a plant. This allows scientists to modify the plant's characteristics at the genetic level, which is the hallmark of transgenic crops. Thus, the right answer is option 'B'.

**Statement 1 is correct:** Plants produced by vegetative propagation are exact copies of the parent plant, as they're produced from a single parent. **Statement 2 is incorrect:** Vegetative propagation may not eliminate viruses. If a virus is present in the parent plant, it will likely be passed on to the new plants as well. **Statement 3 is correct:** Vegetative propagation can be practised most of the year.

The Genetic Engineering Appraisal Committee (GEAC) is the apex body constituted in the Ministry of Environment and Forests under Rules for Manufacture, Use, Import, Export and Storage of Hazardous Microorganisms/Genetically Engineered Organisms or Cells 1989, under the Environment Protection Act, 1986. - The GEAC is responsible for the appraisal of proposals involving the release of genetically engineered organisms and products into the environment including experimental field trials.

Neem-coated Urea dissolves more slowly compared to normal Urea, which helps prevent leaching and ensures a gradual release of nitrogen into the soil. Neem has inhibitory properties that reduce nitrogen loss at multiple stages, including volatilization and denitrification. By slowing down the conversion of Urea into nitrate, it minimizes excess nitrate accumulation, reducing denitrification losses and improving nitrogen use efficiency in crops. To curb misuse and diversion of highly subsidized Urea to the chemical industry, the Government of India made it mandatory for all Urea manufacturers to Neem-coat 100% of their production. This move not only ensures that Urea is used exclusively for agriculture but also enhances soil fertility and crop productivity by improving nitrogen retention.

Scientists from the Botanical Survey of India (BSI) have discovered a new species of banana, Musa indandamanensis, in the remote tropical rainforests of Little Andaman Island. This remarkable species stands out for its exceptional height, reaching up to 11 meters, nearly three times taller than common banana plants. Located 16 km inside the Krishna Nalah forest, this species is globally distinct due to its unique green flowers, an unusually large fruit bunch axis (lux) thrice the size of regular banana species, and cylindrical-shaped flowers instead of the typical conical form. Additionally, the fruit pulp is orange, differing from the usual white or yellow found in common bananas. This discovery adds significant value to botanical research and biodiversity conservation, highlighting the unique flora of the Andaman Islands.

**Pair 1 is correct:** Lead is a heavy metal that has been found in some lipstick formulations, which is concerning due to its potential toxic effects. **Pair 2 is correct:** Brominated vegetable oils (BVOs) are a type of food additive used in some soft drinks to help distribute flavours. BVOs have been controversial and banned in many countries due to potential health concerns. **Pair 3 is correct:** Monosodium glutamate (MSG) is a flavour enhancer commonly used in Chinese and other Asian cuisines, including fast food. There have been concerns about the potential side effects of MSG consumption. Therefore, all three pairs are correctly matched.

Dhara Mustard Hybrid-11, otherwise known as DMH - 11, is a genetically modified hybrid variety of the mustard species Brassica juncea. **Statement 1 is incorrect.** The GM mustard developed in India does not have the property of pest-resistance. It has been genetically modified for hybridization and increased yield, not for pest-resistance. **Statement 2 is correct.** The GM mustard has been developed with genes that allow it to cross-pollinate, leading to hybridization and increased yield. **Statement 3 is incorrect.** The GM mustard was developed by scientists at Delhi University’s Centre for Genetic Manipulation of Crop Plants (CGMCP), not by the IARI and Punjab Agricultural University. So, only statement 2 is correct. 

Steel slag can be used for several purposes, and all of the options listed are valid applications. **Statement 1 is correct.** Steel slag is a common and cost-effective material for use in road base construction due to its high durability, strength, and drainage properties. **Statement 2 is correct.** Crushed steel slag can be used as an amendment for agricultural soil. It can improve drainage, provide some essential nutrients, and even help suppress weeds. **Statement 3 is correct.** Steel slag can be partially substituted for some raw materials in cement production, reducing the need for quarrying and lowering the environmental impact of cement manufacturing. Therefore, the correct answer is 1, 2, and 3.

Bollgard I and Bollgard II technologies are mentioned in the context of developing genetically modified (GM) cotton plants resistant to insect pests. * **Bollgard I:** This was India's first commercially approved GM crop technology introduced in 2002. It incorporates a single gene (Cry1Ac) from the bacterium Bacillus thuringiensis (Bt) into cotton plants. This Bt gene produces an insecticidal protein that targets and kills certain insect pests, particularly the American Bollworm (Helicoverpa armigera). * **Bollgard II:** This is a more advanced technology introduced in mid-2006. It incorporates two genes (Cry1Ac and Cry2Ab) from Bt into cotton. This provides broader resistance against a wider spectrum of insect pests, including lepidopteran caterpillars like the Spodoptera species, in addition to the American Bollworm.

The Lemongrass plant is known to be an excellent mosquito repellant. According to a study conducted in 2011, around 95% of mosquitos from a specific range of species were either killed or completely repelled due to the intense odour of lemongrass oil. Commonly known as Citronella oil, the impact of the essential oil from Lemongrass is known to last for around two and a half hours. For some species of mosquitos, it is even more.

* **Statement 1 is correct:** Biofilms are a major concern in healthcare. They can form on implanted devices like catheters, heart valves, and artificial joints within human tissues. These biofilms can harbour bacteria that are difficult to eradicate with antibiotics, leading to chronic infections and potential implant failure. * **Statement 2 is correct:** Biofilms can also form on food and food processing surfaces. This can contaminate food with bacteria and contribute to spoilage. Biofilms on these surfaces are also challenging to remove due to their protective matrix. * **Statement 3 is correct:** Bacteria within biofilms can exhibit increased resistance to antibiotics. The biofilm matrix acts as a barrier, making it harder for antibiotics to reach and kill the bacteria. Additionally, bacteria within biofilms can communicate and share genetic material, potentially promoting the spread of antibiotic resistance genes. All three statements are correct.

- Ants are well-known as cultivators of fungi. Certain ant species, particularly those in the tribe Attini, have evolved a symbiotic relationship with specific fungi. These ants cultivate the fungus within their nests, providing it with food and a controlled environment. In return, the fungus provides the ants with nutrients. This is a fascinating example of mutualism in nature. - Cockroaches are omnivores and scavengers. They do not cultivate fungi. - Crabs are primarily scavengers or predators. They are not known to cultivate fungi. - Spiders are predators and capture their prey (insects) in webs. They do not cultivate fungi.

**Statement 1 is correct:** The Guchhi mushroom is a species of fungus in the Morchellaceae family of the Ascomycota. It exhibits a pale yellow colouration with large pits and ridges on the surface of the cap, which is elevated on a large white stem. **Statement 2 is correct:** This mushroom is cultivated in the foothills of the Himalayas, specifically in regions such as Himachal Pradesh, Uttaranchal, and Jammu and Kashmir. **Statement 3 is incorrect:** These mushrooms cannot be cultivated on a commercial scale and instead grow naturally in conifer forests across various temperature regions. It takes months for villagers to gather sufficient quantities of these mushrooms, dry them, and transport them to the market.

All three plants—Groundnut, Horse-gram, and Soybean—belong to the pea family, scientifically known as **Leguminosae or Fabaceae.** This family is characterized by plants that produce legumes (pods containing seeds). Here's a breakdown of each: **Groundnut (Arachis hypogaea):** * Groundnut, also known as peanut, belongs to the Leguminosae family. It produces peanuts, which grow underground in pods, typical of legumes. * It is part of the subfamily Faboideae, a major division within the pea family. **Horse-gram (Macrotyloma uniflorum):** * Horse-gram is another plant in the Leguminosae family. It is commonly cultivated in tropical regions and is known for its high protein content and use in animal feed and food. * It belongs to the subfamily Faboideae as well. **Soybean (Glycine max):** * Soybean, one of the most important leguminous crops, also belongs to the Leguminosae family. It is widely grown for its edible beans and oil extraction. * Soybean is part of the subfamily Faboideae too. All three plants are legumes, characterized by their pod-like fruit and ability to fix nitrogen from the atmosphere through a symbiotic relationship with bacteria in their root nodules.