GK: Class 12 General Q&A · Page 153
3,658 free answers on GK (General) for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
Name the organelle of a plant cell where photosynthesis takes place.
Photosynthesis takes place in chloroplasts, the specialized organelles found in plant cells and some protists. These double-membrane-bound structures contain chlorophyll, the green pigment that captures light energy from the sun and converts it into chemical energy stored in glucose molecules. Chloroplasts are most abundant in the leaf cells of plants, particularly in the mesophyll tissue where maximum light exposure occurs. Inside chloroplasts, photosynthesis occurs in two main regio
- GeneralClass 12All
What do the chloroplasts contain?
Chloroplasts contain chlorophyll, the green pigment essential for capturing light energy during photosynthesis. Beyond chlorophyll, they also house other accessory pigments like carotenoids and xanthophylls, which help capture light at different wavelengths and protect the chloroplast from excessive light damage. These pigments are embedded in the thylakoid membranes, organized structures stacked into formations called grana. Additionally, chloroplasts contain their own DNA, ribosomes
- GeneralClass 12All
What are the units of inheritance in living organisms?
Genes are the units of inheritance in living organisms. These are specific segments of DNA that contain coded instructions for producing proteins or functional RNA molecules, thereby determining inherited characteristics and traits. Each gene occupies a particular position on a chromosome and carries information that is passed from parents to offspring during reproduction. Genes control everything from physical characteristics like eye color and height to biochemical processes like en
- GeneralClass 12All
What is 'Project Tiger'? What was the objective of this project?
Project Tiger is a wildlife conservation program launched by the Government of India in 1973 to protect the declining Bengal tiger population and its natural habitats. Initiated when tiger numbers had plummeted to approximately 1,800 individuals due to rampant poaching, habitat destruction, and human-wildlife conflict, this landmark initiative represented India's commitment to preserving its national animal and the ecosystems tigers represent. The project established dedicate
- GeneralClass 12All
The species P and Q of wild animals are found exclusively in a 'particular area'. The species R of wild animals is listed in Red Data Book of India whereas species S of wild animals no longer exists anywhere on the earth. (a) What name is given to species like P and Q? (b) What are the species like R known as? (c) Name one species like R. (d) What is the special name of species like S? (e) Name one species like S.
(a) Species like P and Q that are found exclusively in a particular area are called endemic species. These organisms have restricted geographical distributions and have evolved in isolation to adapt to specific local environmental conditions. Their limited range makes them particularly vulnerable to habitat loss, climate change, or human activities, requiring focused conservation efforts within their native regions. (b) Species like R
- GeneralClass 12All
By taking the example of snakes, explain how by killing small animals, we are actually harming ourselves.
Snakes play a crucial role in controlling rodent populations in agricultural and residential areas. Rats and mice are major pests that consume and contaminate stored grains, spread diseases like plague and leptospirosis, and cause significant economic losses to farmers. When people kill snakes out of fear or misunderstanding, rodent populations explode unchecked, leading to increased crop damage, food losses, and disease transmission. A single rat can consume approximately 15-20 kilograms of
- GeneralClass 12All
Consider the following animal species: Dodo, Yak, Deer, Black buck, Tiger, Crow, Kashmir stag, Dinosaur, Elephant, Lion-tailed macaque, Peacock, Snow leopard. Which of these animals are: (a) Endemic to mountain habitats? (b) Endangered species? (c) Extinct species?
(a) Endemic to mountain habitats:Yak, Kashmir stag (Hangul), and Snow leopard are endemic to mountain habitats. The yak is naturally found in the high-altitude Himalayan and Tibetan plateau regions, adapted to cold temperatures and low oxygen levels. The Kashmir stag is endemic to the mountainous forests of Kashmir, while the snow leopard inhabits the high mountain ranges of Central and South Asia, including the Himalayas, pe
- GeneralClass 12All
Explain how recycling of paper helps in the conservation of forests.
Paper is manufactured primarily from wood pulp obtained by cutting down trees, with approximately 24 trees required to produce one ton of paper. The global demand for paper products—including newspapers, books, notebooks, packaging materials, and office supplies—results in millions of trees being felled annually. When we recycle paper, we significantly reduce the need to harvest fresh timber from forests. Each ton of recycled paper can save approximately 17 trees, along with subst
- GeneralClass 12All
X is a human activity which will cause an increase in temperature of Earth's atmosphere leading to global warming. It can cause soil erosion making the soil infertile and lead to desertification. It can decrease rainfall but increase the flooding of rivers. It can also affect the water cycle and lead to the extinction of many wild species. What is X?
X is deforestation—the large-scale clearing of forests for agriculture, urbanization, logging, or infrastructure development. When trees are removed, the carbon they stored is released into the atmosphere as carbon dioxide, while the forest's capacity to absorb future CO₂ emissions is eliminated. This double impact significantly contributes to increased atmospheric carbon dioxide levels, strengthening the greenhouse effect and causing global warming. Trees also release
- GeneralClass 12All
1. What do you mean by the term conservation?
Conservation refers to the planned management and protection of natural resources, wildlife, ecosystems, and biodiversity to prevent their depletion, degradation, or extinction. It involves sustainable practices that balance human needs with environmental preservation, ensuring that forests, water bodies, soil, plants, and animals remain healthy and available for future generations. Conservation strategies include protecting habitats, regulating hunting and logging, controlling pollution, and
- GeneralClass 12All
. Which biosphere reserve is located in Assam?
The Dibru-Saikhowa Biosphere Reserve is located in Assam, situated in the floodplains of the Brahmaputra River in the northeastern region of India. This reserve, designated in 1999, encompasses unique wetland ecosystems, tropical forests, and grasslands that support diverse wildlife including the endangered white-winged wood duck, hoolock gibbons, and wild horses (feral horses). The reserve covers approximately 765 square kilometers and represents one of the most important conservation areas
- GeneralClass 12All
Name a biosphere reserve that contains other protected areas in it.
The Nilgiri Biosphere Reserve contains multiple protected areas within its boundaries, including the Mudumalai Wildlife Sanctuary, Bandipur National Park, Nagarhole National Park, Mukurthi National Park, Silent Valley National Park, and parts of Wayanad Wildlife Sanctuary. Established in 1986, this biosphere reserve spans across the states of Tamil Nadu, Karnataka, and Kerala in the Western Ghats mountain range, covering approximately 5,520 square kilometers. This design reflects the core pri
- GeneralClass 12All
What is meant by extinct species?
Extinct species are those that have completely disappeared from Earth, with no living individuals remaining anywhere in the wild or in captivity. Extinction represents the permanent loss of a species, meaning it can never be recovered or restored naturally. Famous examples include the dodo bird, passenger pigeon, Tasmanian tiger (thylacine), and numerous dinosaur species. Once extinction occurs, the unique genetic information, ecological role, and evolutionary history of that species are lost
- GeneralClass 12All
What is reforestation?
Reforestation is the process of replanting trees in areas where forests previously existed but were cleared, degraded, or destroyed through logging, agriculture, fire, or other disturbances. Unlike afforestation (planting forests in areas that were never forested), reforestation aims to restore forest cover to lands that historically supported forests. This practice helps rebuild ecosystems, restore biodiversity, replenish timber resources, and reverse environmental damage caused by deforesta
- GeneralClass 12All
. Why some animals migrate?
Animals migrate primarily to access better resources, escape harsh environmental conditions, and enhance their survival and reproductive success. Migration involves regular, seasonal movements between different regions, typically driven by the availability of food, water, and suitable breeding grounds. Many bird species, for instance, fly thousands of kilometers from cold winter regions to warmer areas where insects, seeds, and nesting sites are abundant. Similarly, terrestrial animals like w
- GeneralClass 12All
How does the fertility of soil decreases due to deforestation?
Deforestation dramatically reduces soil fertility by disrupting the natural nutrient cycling processes that forests maintain. In healthy forests, fallen leaves, branches, fruits, and dead organisms decompose on the forest floor, continuously releasing nitrogen, phosphorus, potassium, and other essential nutrients back into the soil. Tree roots also help break down rocks and minerals, making nutrients accessible to plants. When trees are removed, this nutrient recycling system collapses—
- GeneralClass 12All
What will happen if the top layer of soil is exposed?
When the top layer of soil (topsoil) is exposed without protective vegetation cover, it becomes highly vulnerable to rapid erosion by wind and water, leading to severe land degradation. Topsoil contains the highest concentration of organic matter, nutrients, beneficial microorganisms, and the root systems that support plant growth—it is the most fertile and biologically active soil layer. Once exposed to direct sunlight, rain, and wind, this precious layer quickly washes away during rai
- GeneralClass 12All
In what way some tribals depend on forests?
Many tribal communities have deep, multi-dimensional dependencies on forests that span their food security, livelihoods, shelter, medicine, culture, and identity. Forests provide tribals with diverse food sources including fruits, roots, tubers, honey, mushrooms, edible leaves, and wild game—these forest products supplement or sometimes constitute their primary diet. They collect fuelwood for cooking and heating, timber and bamboo for building homes and crafting tools, and various plant
- GeneralClass 12All
Write four main reasons for which trees in the forest are cut?
Trees in forests are cut primarily for four major reasons that drive global deforestation. First, agricultural expansion represents the largest cause—forests are cleared to create farmland for growing crops like soybeans, palm oil, coffee, and cocoa, or to establish pastures for cattle ranching. As human populations grow and demand for food increases, vast forest areas are converted to agricultural land, particularly in tropical regions. Second, commercial logging for timber and wood pr
- GeneralClass 12All
What is the difference between afforestation and reforestation?
Afforestation and reforestation both involve planting trees, but they differ fundamentally in the historical land use of the target areas. Afforestation refers to establishing forests on land that has not been forested in recent history—typically barren land, deserts, degraded grasslands, or areas that have been non-forested for at least 50 years or more. This practice creates entirely new forests where none previously existed, expanding overall forest cover beyond historical levels. Ex