As we move from the equator towards the poles, species diversity generally:
- Fluctuates completely randomly
- Remains strictly constant
- Generally decreases
- Generally increases
Explanation: Latitudinal gradients show that species diversity decreases as we move away from the equator towards the poles.
The technique of storing viable gametes of threatened species at ultra-low temperatures using liquid nitrogen is called:
- Cold maceration
- Tissue culture
- In vitro fertilization
- Cryopreservation
Explanation: Cryopreservation is an advanced ex-situ conservation method that freezes biological material at $-196^{\circ}\text{C}$ to maintain viability for years.
If the species-area relationship is analyzed across entire continents, the Z value ranges between:
- 2.0 to 3.0
- 0.1 to 0.2
- 0.6 to 1.2
- 1.5 to 2.0
Explanation: For very large areas like entire continents, the slope of the line becomes much steeper, with Z values ranging from 0.6 to 1.2.
The variation in reserpine concentration in Rauwolfia vomitoria is an example of:
- Genetic diversity
- Species diversity
- Ecosystem diversity
- Ecological diversity
Explanation: The medicinal plant Rauwolfia vomitoria growing in Himalayan ranges shows genetic diversity in the potency and concentration of the active chemical reserpine.
For smaller taxonomic groups within a specific region, the normal range of the Z value is:
- 1.0 to 1.5
- 1.5 to 2.0
- 0.6 to 1.2
- 0.1 to 0.2
Explanation: Ecologists have discovered that the value of Z generally lies in the narrow range of 0.1 to 0.2 for smaller areas, regardless of the taxonomic group.
Endemic species are biologically defined as those that are found:
- Only in zoos
- In one region
- In multiple continents
- Globally everywhere
Explanation: Endemism refers to species that are confined to a specific geographical region and are found nowhere else in the world.
The historic 'Earth Summit' (United Nations Conference on Environment and Development) held in 1992 took place in:
- Rio de Janeiro
- Paris
- Johannesburg
- Kyoto
Explanation: The Earth Summit was held in Rio de Janeiro in 1992, calling upon all nations to take appropriate measures for the conservation of biodiversity.
The 'Sixth Extinction' currently in progress is distinct from previous mass extinctions primarily due to its:
- Climatic impact
- Rate of extinction
- Geographic extent
- Taxonomic targets
Explanation: While mass extinctions have occurred before, the current 'Sixth Extinction' is unique because its rate is exceptionally fast and driven by human activity.
The dramatic decrease in the population of pollinating insects is a direct threat to which ecosystem service?
- Nutrient cycling
- Soil formation
- Crop pollination
- Climate regulation
Explanation: Pollination is a crucial ecosystem service provided by insects like bees and bumblebees, essential for the production of many crops.
Which of the following ecosystem services represents a 'broadly utilitarian' argument?
- Timber extraction
- Medicine derivation
- Oxygen production
- Bioprospecting
Explanation: Broadly utilitarian arguments focus on ecosystem services that nature provides, such as producing 20% of the Earth's oxygen via the Amazon rainforest.
Steller's sea cow, an extinct massive marine mammal, was originally native to:
- Russia
- Australia
- Africa
- Mauritius
Explanation: Steller's sea cow was found in the Bering Sea near Russia and was hunted to extinction within decades of its discovery.
The 'World Summit on Sustainable Development', which resulted in a pledge by 190 countries to reduce biodiversity loss by 2010, was held in 2002 in:
- New York
- Johannesburg
- Geneva
- Rio de Janeiro
Explanation: Held in Johannesburg, South Africa, this summit secured pledges to achieve a significant reduction in the current rate of biodiversity loss at global and regional levels.
Among the 'Evil Quartet', which is considered the most important cause driving animals to extinction?
- Co-extinctions
- Alien species invasions
- Overexploitation
- Habitat loss
Explanation: Habitat loss and fragmentation are the primary and most significant drivers of species extinctions globally.
The term 'Biodiversity' was popularized by which prominent sociobiologist?
- Edward Wilson
- Paul Ehrlich
- Alexander von Humboldt
- Robert May
Explanation: Edward Wilson popularized the term biodiversity to describe the combined diversity at all the levels of biological organization.
Among vertebrates, which taxonomic group exhibits the highest global species diversity?
- Mammals
- Fishes
- Birds
- Reptiles
Explanation: Fishes form the largest group among vertebrates, representing roughly half of all known vertebrate species.
The introduction of the Nile perch into Lake Victoria led to the extinction of over 200 species of:
- Cichlid fishes
- Tilapia fishes
- Lungfishes
- Catfishes
Explanation: The Nile perch, an invasive alien species, predated heavily on the endemic cichlid fishes of Lake Victoria, causing a mass local extinction.
The current rate of species extinction is estimated to be how many times faster than pre-human times?
- 100 to 1000
- 2 to 5
- 10 to 50
- 5000 to 10000
Explanation: Ecologists estimate that the current 'Sixth Extinction' rate is 100 to 1,000 times faster than the natural background extinction rates of the past.
According to the Critical Ecosystem Partnership Fund (CEPF) and recent ecological assessments, what is the total number of globally identified biodiversity hotspots?
Explanation: There are currently 36 recognized biodiversity hotspots globally according to the Critical Ecosystem Partnership Fund (CEPF). While Norman Myers initially identified 25 hotspots in 1999, the list has been periodically updated over the years to reflect new ecological data.
According to Robert May's global estimate, the total number of species on Earth is roughly:
- Fifty million
- Seven million
- Twenty million
- Ten million
Explanation: Robert May placed the global species diversity at about 7 million, a more conservative and scientifically sound estimate compared to earlier gross projections.
In the species-area relationship equation $S = CA^Z$, what does 'Z' represent?
- Area examined
- Species richness
- Y intercept
- Regression coefficient
Explanation: In the equation, Z represents the slope of the line, also known as the regression coefficient.
The 'Species-Area Relationship' was observed and proposed by the German naturalist:
- Charles Darwin
- Paul Ehrlich
- Alexander von Humboldt
- Robert May
Explanation: Alexander von Humboldt observed that within a region, species richness increased with increasing explored area, but only up to a limit.
Conservation of species within their natural ecosystem or habitat is termed:
- Ex situ conservation
- Cryopreservation
- Tissue culture
- In situ conservation
Explanation: In-situ (on-site) conservation protects endangered species in their natural habitats, such as in national parks and wildlife sanctuaries.
The extinction of Steller's sea cow and the passenger pigeon was directly caused by:
- Overexploitation
- Alien species
- Co-extinctions
- Habitat fragmentation
Explanation: These species became extinct in the last 500 years entirely due to overexploitation by humans for food and resources.
Sacred groves, which act as strict in-situ conservation refuges, are found in the Khasi and Jaintia Hills of:
- Rajasthan
- Maharashtra
- Madhya Pradesh
- Meghalaya
Explanation: Sacred groves in Meghalaya are tracts of forest set aside and venerated by local communities, providing refuge for rare and threatened plants.
The Thylacine, commonly known as the Tasmanian wolf, went extinct primarily in:
- Africa
- Australia
- South America
- Asia
Explanation: The Thylacine was a large carnivorous marsupial native to Tasmania, New Guinea, and the Australian mainland.
Which of the following strictly represents an 'ex-situ' conservation strategy for animals?
- Wildlife sanctuaries
- Biosphere reserves
- National parks
- Zoological parks
Explanation: Zoological parks (zoos) keep animals in captivity outside their natural habitats, making them an ex-situ conservation method.
India's share of global species diversity makes it one of the 12 mega diversity countries. What is this share?
- 8.1 percent
- 20.5 percent
- 2.4 percent
- 12.0 percent
Explanation: Despite having a small land area, India shares 8.1 percent of the global species diversity.
Which of the following is an exotic weed that became highly invasive and damaging in India?
- Parthenium
- Mangifera indica
- Nelumbo nucifera
- Ficus religiosa
Explanation: Parthenium (carrot grass), along with Lantana and water hyacinth, is an invasive weed species that poses a major threat to native biodiversity.
According to current IUCN Red List data regarding species conservation, what is the estimated percentage of all bird species globally facing the threat of extinction?
- 23 percent
- 31 percent
- 12 percent
- 32 percent
Explanation: Current IUCN Red List conservation metrics indicate that approximately 11.5% to 12% of all bird species globally face the threat of extinction. For broader context, updated assessments show that around 26-27% of mammals, 41% of amphibians, and 34% of conifers (gymnosperms) are currently threatened.
A severe loss of biodiversity in a region is most likely to lead to a decrease in:
- Pathogen attack
- Disease incidence
- Pest resistance
- Plant production
Explanation: Loss of biodiversity generally leads to a decline in plant production, lowered resistance to environmental perturbations, and increased variability.
How many biodiversity hotspots globally encompass parts of India's high biodiversity regions?
Explanation: Three hotspots cover India's high biodiversity regions: Western Ghats and Sri Lanka, Indo-Burma, and Himalaya.
When a host fish species becomes extinct, its unique assemblage of parasites also disappears. This is an example of:
- Co-extinctions
- Habitat fragmentation
- Overexploitation
- Competitive exclusion
Explanation: Co-extinction occurs when a species relies on another obligately; the extinction of one inevitably leads to the extinction of the other.
According to IUCN data, which taxonomic group currently faces the highest global threat of extinction?
- Birds
- Mammals
- Gymnosperms
- Amphibians
Explanation: Amphibians face the highest threat of extinction, with approximately 32 percent of all amphibian species currently facing the threat of extinction.
The Dodo, a famously extinct flightless bird, was endemic to which island nation?
- Mauritius
- New Zealand
- Australia
- Madagascar
Explanation: The Dodo was a flightless bird native to the island of Mauritius in the Indian Ocean that was driven to extinction by human activities.
The 'narrowly utilitarian' argument for biodiversity conservation primarily focuses on:
- Aesthetic value
- Spiritual fulfillment
- Oxygen production
- Direct economic benefits
Explanation: The narrowly utilitarian argument focuses on the countless direct economic benefits humans derive from nature, such as food, firewood, fiber, and medicines.
On a logarithmic scale, the species-area relationship graphically appears as a:
- Straight line
- Rectangular hyperbola
- Sigmoid curve
- Parabolic curve
Explanation: While the relationship is a rectangular hyperbola on a linear scale, plotting it on a log-log scale results in a straight line described by the equation $\log S = \log C + Z \log A$.
Which of the following ecosystems harbors the greatest biodiversity on Earth?
- Amazon rainforest
- Alpine tundra
- Sahara desert
- Taiga biome
Explanation: The largely undisturbed Amazonian rainforests in South America contain the greatest biodiversity of any ecosystem on the planet.
To qualify as a 'Biodiversity Hotspot', a region must possess high species richness and high levels of:
- Extinction rate
- Mutation rate
- Migration rate
- Endemism
Explanation: Hotspots are regions with very high levels of species richness and high degree of endemism (species found strictly there and nowhere else).
The Quagga, a recently extinct mammal species resembling a zebra, was native to:
- Australia
- Africa
- South America
- North America
Explanation: The Quagga was a subspecies of the plains zebra that lived in South Africa until it was hunted to extinction in the late 19th century.
A species facing an extremely high risk of extinction in the wild in the immediate future is categorized as:
- Endangered
- Vulnerable
- Extinct
- Critically endangered
Explanation: The 'Critically endangered' category indicates the highest risk level for a wild species, just one step away from being extinct in the wild.
The ethical argument for biodiversity conservation emphasizes that every species possesses an:
- Intrinsic value
- Extrinsic value
- Utilitarian value
- Market value
Explanation: The ethical argument states that all species have an intrinsic value, even if they are not of current or any apparent economic value to humans.
According to the NCERT biology data, how many 'Biosphere Reserves' were established in India?
Explanation: India has a history of religious and cultural traditions that emphasize nature protection, establishing 14 biosphere reserves, 90 national parks, and 448 wildlife sanctuaries (as per older NCERT texts).
Clarias gariepinus (African catfish) introduced illegally for aquaculture poses a severe threat to indigenous:
- Catfishes
- Trout
- Salmon
- Carps
Explanation: The illegal introduction of the African catfish for aquaculture is threatening the native indigenous catfishes in Indian rivers.
While often colloquially referred to as the 'lungs of the Earth', what is the approximate net contribution of the Amazon rainforest to the Earth's total global atmospheric oxygen?
- Nearly 0 percent
- Roughly 20 percent
- Exactly 50 percent
- More than 75 percent
Explanation: It is a widespread myth that the Amazon produces 20% of the world's breathable oxygen. While it produces a large amount of oxygen through photosynthesis, the forest ecosystem (including microbes, plants, and animals) consumes almost all of it through respiration and decomposition. The net contribution to global atmospheric oxygen is near zero. The vast majority of Earth's atmospheric oxygen is produced by marine phytoplankton.
Which of the following is an invasive weed species causing severe environmental damage in India?
- Azadirachta indica
- Ficus religiosa
- Water hyacinth
- Mangifera indica
Explanation: Eichhornia (Water hyacinth), along with Parthenium and Lantana, is an invasive alien weed that aggressively overtakes native aquatic ecosystems.
The IUCN Red List (2004) documents the extinction of how many species in the last 500 years?
- 350 species
- 784 species
- 500 species
- 1000 species
Explanation: According to the IUCN Red List (2004), 784 species (including 338 vertebrates, 359 invertebrates, and 87 plants) have gone extinct in the last 500 years.
In the Rivet Popper Hypothesis, the popping of a 'key rivet' on the airplane wing represents the loss of a:
- Migratory species
- Redundant species
- Keystone species
- Pioneer species
Explanation: Loss of a keystone species (a key rivet on the wing) poses a much more immediate and severe threat to the ecosystem's structural integrity than losing a redundant species.
The term 'Lungs of the planet', harboring massive biodiversity, refers to the:
- Congo basin
- Taiga forests
- Coral reefs
- Amazon rainforest
Explanation: The Amazon rainforest is often called the 'lungs of the planet' because it produces a significant portion of the world's oxygen and houses immense biodiversity.
Which of the following represents an 'Ex-situ' conservation strategy?
- Wildlife sanctuaries
- National parks
- Seed banks
- Biosphere reserves
Explanation: Ex-situ (off-site) conservation involves protecting species outside their natural habitats, such as in seed banks, zoological parks, and botanical gardens.
Exploring molecular, genetic, and species-level diversity for products of economic importance is known as:
- Bioremediation
- Bioprospecting
- Biomagnification
- Biofortification
Explanation: Bioprospecting involves searching biological resources for useful products, which nations with rich biodiversity can exploit economically.
According to standard NCERT biology data, how many 'National Parks' were present in India?
Explanation: Historically referenced in NCERT texts, India protected its biodiversity through 90 national parks and numerous wildlife sanctuaries.
David Tilman's long-term ecosystem experiments using outdoor plots demonstrated that increased species diversity led to:
- Increased variability
- Higher productivity
- Lower productivity
- Total collapse
Explanation: Tilman found that plots with more species showed less year-to-year variation in total biomass and generally contributed to higher productivity.
The 'Rivet Popper Hypothesis', used to explain the importance of biodiversity, was proposed by:
- Robert May
- Paul Ehrlich
- David Tilman
- Edward Wilson
Explanation: Stanford ecologist Paul Ehrlich used the rivet popper hypothesis to analogize ecosystems to airplanes and species to the rivets holding them together.
Biosphere reserves structurally differ from national parks primarily because they permit:
- Exotic species introduction
- Limited human activity
- Unlimited sport hunting
- Total habitat destruction
Explanation: Biosphere reserves have a zoned approach (core, buffer, transition) that allows for sustainable human activity and research in the outer zones.
The term 'Evil Quartet' is used by ecologists specifically in the context of:
- Biodiversity loss
- Climate change
- Population growth
- Ozone depletion
Explanation: The 'Evil Quartet' refers to the four major causes of biodiversity loss: habitat loss, overexploitation, alien species invasions, and co-extinctions.
India accounts for what percentage of the world's total land area?
- 15.0 percent
- 2.4 percent
- 8.1 percent
- 12.5 percent
Explanation: India has only 2.4 percent of the world's land area, yet it contributes an impressive 8.1 percent to global species diversity.
Among all the recorded animal species globally, the most species-rich taxonomic group is:
- Crustaceans
- Insects
- Fishes
- Molluscs
Explanation: Insects make up more than 70 percent of all the total recorded animal species, making them the most species-rich taxonomic group.
The concept of 'Biodiversity Hotspots' was first developed and introduced by:
- Edward Wilson
- Robert May
- Paul Ehrlich
- Norman Myers
Explanation: Norman Myers introduced the concept of biodiversity hotspots in 1988 to identify regions with high endemism and exceptional habitat loss.
Which of the following is a recently extinct subspecies of the tiger?
- Javan
- Bengal
- Siberian
- Sumatran
Explanation: The Bali, Javan, and Caspian tigers are three subspecies of the tiger that have gone extinct in recent history.
The Western Ghats having a greater amphibian species diversity than the Eastern Ghats illustrates:
- Species diversity
- Genetic diversity
- Ecological diversity
- Biome diversity
Explanation: Species diversity refers to the variety of species within a region, such as the high amphibian richness in the Western Ghats.