Biogeography & Ecosystems

Oxygen on Earth mainly comes from photosynthesis, especially by phytoplankton (marine organisms), and oxygen levels differ between air and water. ❌ Statement I is incorrect:
* Oceans (phytoplankton) produce more oxygen than rainforests. ✅ Statement II is correct:
* Marine phytoplankton and photosynthetic bacteria produce about 50% of the world’s oxygen. ❌ Statement III is incorrect:
* Atmospheric air has much more oxygen than surface water; water does not contain several folds higher oxygen than air. So, the correct answer is: B

1. Carabid beetles: Many carabid beetles are predatory, and some species are known to be parasitoids, particularly of other insects.  2. Centipedes: Centipedes are predatory arthropods and not parasitoids. They hunt and kill their prey. 3. Flies: The order Diptera (flies) includes a large number of parasitoid species. For example, Tachinid flies are parasitoids of various insects. 4. Termites: Termites are not parasitoids. They are social insects that primarily feed on wood and other plant matter. 5. Wasps: The order Hymenoptera (wasps, bees, ants) has numerous parasitoid species. Many wasp species are parasitoids, laying their eggs on or in other insects. _Therefore, parasitoid species are found in Carabid beetles, Flies, and Wasps._

Fig-Wasp Mutualism: Figs and fig wasps share an obligate mutualistic relationship, meaning they are entirely dependent on each other for survival and reproduction. Fig wasps are the only insects that can pollinate fig trees, and fig trees are the sole source of food and shelter for developing fig wasps. Highly Specialized Pollination: The fig fruit (technically a syconium) has its flowers enclosed within. Female fig wasps enter the syconium through a tiny opening called the ostiole. They lay eggs inside and pollinate the flowers in the process. Coevolution: This intricate relationship is a classic example of coevolution, where two species have evolved together over millions of years, with each species' adaptations influencing the other's. _The other options are incorrect:_ * Mahua (B): It is pollinated by various insects and even bats. Mahua (Madhuca indica) is found in the dry deciduous type of forests like the Forests of Chhattisgarh and Jharkhand. * Sandalwood (C): It is primarily pollinated by bees and flies. Sandalwood is a dry deciduous forest species native to China, India, Indonesia, Australia, and the Philippines. Sandalwood is listed as Vulnerable in the IUCN Red list. Sandalwood grows as a partial or hemiparasite, relying on the presence of four or five other trees nearby. Beneath the ground, its roots develop a haustorium, an octopus-like structure that attaches to the host tree's roots, drawing water and nutrients from them.  * Silk cotton (D): It is pollinated by bats and birds. The Silk Cotton Tree is a tropical deciduous tree native to the Indian subcontinent and other parts of Southeast Asia. It produces a capsule that, when ripe, contains white fibres like cotton.

Congo Basin Peatlands: The Congo Basin in Central Africa is home to the world's largest tropical peatland complex. This vast peatland stores an immense amount of carbon, estimated to be equivalent to about three years of global fossil fuel emissions.  Importance of Peatlands: Peatlands are a critical carbon sink. They store more carbon than all the world's forests combined. When peatlands are drained or degraded, this stored carbon is released into the atmosphere, contributing to climate change. The Republic of Congo, the Democratic Republic of Cong and Indonesia are parties to the Brazzaville Declaration, aimed at protecting the Cuvette Centrale region in the Congo Basin, the world’s largest tropical peatlands, from unregulated land use and preventing its drainage and degradation.  _Other Options:_  * Amazon Basin: While the Amazon is known for its vast rainforests, it is not the primary location of the world's largest tropical peatland. * Kikori Basin: The Kikori Basin is located in Papua New Guinea and contains significant peatlands, but not the largest tropical peatland complex. * Rio de la Plata Basin: This basin in South America is primarily known for its grasslands and is not associated with major peatland areas.

1. Brazil - Indri: Indris are _lemurs_ found only in Madagascar, not Brazil. So, this pair is incorrect. 2. Indonesia - Elk: Elks are found in North America, Europe, and Asia, but not in Indonesia. This pair is incorrect. 3. Madagascar - Bonobo: Bonobos are found in the Democratic Republic of Congo, not Madagascar. This pair is also incorrect. Therefore, none of the pairs are correctly matched.

* Cashew: Originally native to Brazil, cashew was brought to India by Portuguese traders in the 16th century.  * Papaya: Papaya also originated in the Americas, specifically in southern Mexico and Central America.  * Red Sanders: This tree, known for its valuable reddish wood, is endemic to India. It is found in the Eastern Ghats, particularly in Andhra Pradesh. Therefore, only Red Sanders is native to India.

* Statement 1 is incorrect: This is typically done using X-ray scanners or advanced imaging technologies like millimeter wave scanners, not traditional radar. * Statement 2 is correct: Radars, specifically weather radars, are commonly used to monitor precipitation. They can detect rain, snow, and other weather conditions by bouncing radio waves off precipitation particles. * Statement 3 is correct: Radars can be used to track the migration of birds and other animals. They are often used in ornithological studies to monitor bird migration patterns.

* Statement I is correct: Marsupials, which are a type of mammal characterised by the presence of a pouch (marsupium) for carrying their young, are not naturally found in India. Marsupials are primarily native to the Americas and Australia.  * Statement II is incorrect: Marsupials can thrive in a variety of habitats, not just montane grasslands without predators. Many marsupial species are found in a wide range of ecosystems, including forests, savannas, and even urban areas, and can coexist with a variety of predators. Therefore, the correct answer is: Statement-I is correct, and Statement II is incorrect.

* Statement I is incorrect: The soil in tropical rainforests is not rich in nutrients. The heavy rainfall in these regions washes away the nutrients from the soil, preventing them from accumulating. * Statement II is correct: In tropical rainforests, high temperature and humidity help dead plants and animals decompose quickly. The warmth and moisture create the perfect conditions for bacteria and fungi, which are tiny organisms that break down dead material. These decomposers work faster in such an environment, turning dead matter into nutrients that go back into the soil to support new plant growth. Therefore, Statement-I is incorrect but Statement-II is correct.

Methane and nitrous oxide emissions from rice farms could have the same long-term warming impact as about 600 coal plants. Rice cultivation emits methane and nitrous oxide due to flooded fields and nitrogen-based fertilizers. Flooding creates anaerobic conditions, producing methane released through rice plants. Fertilizers poorly absorbed by rice lead to soil microbes converting nitrogen into nitrous oxide.