CUET UG Biology Booster Test 2-Causes of Species Extinction -

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CUET UG Biology Booster Test 2-Causes of Species Extinction

⏱️ 30 Minutes

❓ 20 Questions

📌 Answers are locked once submitted — results and explanations appear at the end.

CUET UG Biology Booster Test 2-Causes of Species Extinction

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QUESTION 1 OF 20

Evaluate the following statements regarding 'The Evil Quartet':
I. It refers exclusively to the natural factors causing mass extinctions.
II. Habitat loss and fragmentation is considered the most important cause driving species to extinction.
III. Alien species invasions and co-extinctions form two of the four major causes. Which of the statements accurately describe the Evil Quartet?

Answer Review

1 Evaluate the following statements regarding 'The Evil Quartet':
I. It refers exclusively to the natural factors causing mass extinctions.
II. Habitat loss and fragmentation is considered the most important cause driving species to extinction.
III. Alien species invasions and co-extinctions form two of the four major causes. Which of the statements accurately describe the Evil Quartet?

A II and III only

B I and II only

C I and III only

D I, II, and III

💡 Short Explanation

The Evil Quartet describes anthropogenic, not natural, causes of extinction. Habitat loss is the primary driver. Alien species and co-extinctions are components of the four major causes.

✅ Correct Answer Explanation

The 'Evil Quartet' refers to anthropogenic (human-driven) causes of species extinction: Habitat loss, Over-exploitation, Alien species invasions, and Co-extinctions. Statement I is false because these are human-driven, not natural factors. Statements II and III are correct as they identify the primary cause and two of the secondary causes of the quartet respectively.

❓ Why Other Options Are Incorrect

Option B → Includes statement I, which is factually incorrect regarding the origin of the 'Evil Quartet'.
Option C → Includes statement I and omits the correct statement II.
Option D → Includes statement I, rendering it incorrect.

🎯 Strategy

Used: Elimination

Application: Eliminating statements that incorrectly define the nature of the quartet (anthropogenic vs. natural).

Final Logic: The quartet is anthropogenic; therefore, Statement I is false.

🧠 Memory Trick

"Quartet = Human-driven (Not natural)."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: The Evil Quartet

2 Which of the following scenarios does NOT directly represent one of the primary drivers under 'The Evil Quartet' causing accelerated species extinction?

A Breaking up large mammalian habitats into smaller territories.

B Harvesting commercially important fish beyond their recovery capacity.

C Increased solar energy availability in the tropics promoting speciation.

D Deliberate introduction of Nile perch into an isolated lake ecosystem.

💡 Short Explanation

Habitat fragmentation (A) is a driver. Over-exploitation (B) is a driver. Alien species introduction (D) is a driver. Solar energy and speciation (C) are natural evolutionary patterns, not extinction drivers.

✅ Correct Answer Explanation

The Evil Quartet consists of habitat loss, over-exploitation, alien invasions, and co-extinction. Option C describes the "Latitudinal Gradient" effect on biodiversity, which promotes speciation, not extinction. It is not a driver of accelerated species loss in the context of the Evil Quartet.

❓ Why Other Options Are Incorrect

Option A → Represents 'Habitat loss and fragmentation'.
Option B → Represents 'Over-exploitation'.
Option D → Represents 'Alien species invasions'.

🎯 Strategy

Used: Odd One Out

Application: Identifying that A, B, and D fit the Evil Quartet, while C describes a positive evolutionary phenomenon.

Final Logic: Speciation drivers are not extinction drivers.

🧠 Memory Trick

"Speciation is not Extinction."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: The Evil Quartet

3 Arrange the sequence of progressive habitat loss impacts from human intervention to species decline.
I. Large continuous habitats are broken into small fragments.
II. Human activities demand cultivation for soya beans or beef cattle.
III. Mammals and birds requiring large territories are badly affected.
IV. Severe population declines occur in the affected species.

A II → III → I → IV

B I → II → III → IV

C II → I → III → IV

D III → I → IV → II

💡 Short Explanation

Human demand (II) leads to clearing. Clearing causes fragmentation (I). Large territory species struggle (III). Struggles lead to population crashes (IV).

✅ Correct Answer Explanation

The logical progression is: Human demand (II) causes physical habitat destruction/fragmentation (I). This impacts sensitive species needing space (III), eventually resulting in their population decline (IV).

❓ Why Other Options Are Incorrect

Option A, B, D misarrange the causal chain leading from human activity to population loss.

🎯 Strategy

Used: Substitution

Application: Following the logical cause-and-effect chain described in the text.

Final Logic: Activity -> Habitat loss -> Niche impact -> Decline.

🧠 Memory Trick

"Demand -> Fragment -> Struggle -> Decline."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Habitat Fragmentation

📄 Passage

"The accelerated rates of species extinctions that the world is facing now are largely due to human activities. There are four major causes ('The Evil Quartet' is the sobriquet used to describe them). (i) Habitat loss and fragmentation: This is the most important cause driving animals and plants to extinction. The most dramatic examples of habitat loss come from tropical rain forests."

Based on the passage, the phrase 'The Evil Quartet' is used as a sobriquet to describe what specific phenomenon?

A The four types of ecosystems most resilient to human activities.

B The four major causes of the accelerated rates of species extinctions.

C The four most endangered tropical rain forests globally.

D The four groups of animals most vulnerable to habitat loss.

💡 Short Explanation

The passage defines 'The Evil Quartet' directly. It relates to "accelerated rates of species extinctions." It identifies the "four major causes."

✅ Correct Answer Explanation

The passage explicitly defines 'The Evil Quartet' as a sobriquet (nickname) used to describe the four major causes behind the world's current accelerated rate of species extinction.

❓ Why Other Options Are Incorrect

Option A, C, and D are incorrect definitions not supported by the passage text.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Directly matching the phrase in the passage to its definition.

Final Logic: Evil Quartet = 4 Causes of Extinction.

🧠 Memory Trick

"Quartet = 4 Extinction Causes."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: The Evil Quartet

📄 Passage

Why does the passage highlight tropical rain forests when discussing habitat loss and fragmentation?

A Because they are entirely immune to fragmentation.

B Because they currently cover more than 14 per cent of the land surface.

C Because they only contain animals that do not require large territories.

D Because they provide the most dramatic examples of habitat loss.

💡 Short Explanation

Passage explicitly cites tropical rain forests. They are "dramatic examples." Fragmentation is the specific concern.

✅ Correct Answer Explanation

The passage mentions that the "most dramatic examples of habitat loss come from tropical rain forests." This explains their significance in the discussion of habitat fragmentation.

❓ Why Other Options Are Incorrect

Option A → Tropical rain forests are highly susceptible to fragmentation.
Option B → They currently cover less than 6%, not more than 14%.
Option C → They harbor many species that do require large territories, making them vulnerable.

🎯 Strategy

Used: Substitution

Application: Directly recalling the reason provided in the passage.

Final Logic: Tropical forests = Dramatic examples.

🧠 Memory Trick

"Rain forest = Dramatic loss."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Habitat Loss

6 An ecologist notes that a specific mammal population is declining rapidly despite the total forested area remaining relatively stable, but a new highway network has divided the forest into multiple distinct grids. Which specific mechanism of the Evil Quartet is primarily at work?

A Alien species invasions

B Over-exploitation

C Habitat fragmentation impacting large territory requirements

D Co-extinction

💡 Short Explanation

Division into "distinct grids" = Fragmentation. "Mammal population declining" + "large territory" requirement = Classic fragmentation impact.

✅ Correct Answer Explanation

The highway system creating "distinct grids" is the definition of habitat fragmentation. Since large-territory mammals cannot move freely between these grids, their population declines as their functional home range is reduced.

❓ Why Other Options Are Incorrect

Option A, B, and D are different drivers of extinction not implied by the road construction scenario.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Identifying the described environmental change (roads/grids) as habitat fragmentation.

Final Logic: Road division = Fragmentation.

🧠 Memory Trick

"Grid = Fragment."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Habitat Fragmentation

7 If a conservationist argues that human dietary and agricultural trends are directly destroying the 'lungs of the planet', which specific activities mentioned in the text support this claim?

A Overharvesting of marine fish and coral mining

B Cultivating soya beans and raising beef cattle

C Introducing Nile perch and African catfish

D Cultivating medicinal plants and orchids

💡 Short Explanation

"Lungs of the planet" = Amazon. Deforestation drivers = Soya + Beef. These are the specific agricultural activities mentioned in the chapter.

✅ Correct Answer Explanation

The chapter explicitly links the destruction of the Amazon rainforest ("lungs of the planet") to clearing land for soya bean cultivation and converting forests into grasslands for beef cattle.

❓ Why Other Options Are Incorrect

Option A, C, and D are other environmental issues discussed, but they do not specifically relate to the clearing of the Amazon rainforest in the provided text.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Retrieving the causes of Amazon deforestation from the text.

Final Logic: Amazon = Soya/Beef.

🧠 Memory Trick

"Amazon = Soya/Beef."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Amazon Deforestation

8 Match the cause of ecosystem degradation with its specific outcome or target.

Column 1	Column 2
1. Conversion to grasslands	P. Degradation of many habitats threatening species survival
2. Pollution	Q. Cutting and clearing the Amazon rain forest
3. Cultivating soya beans	R. Raising beef cattle in the Amazon
4. Unintentional introduction	S. Turning an alien species into an invasive threat

A 1-R, 2-Q, 3-P, 4-S

B 1-Q, 2-S, 3-R, 4-P

C 1-P, 2-R, 3-S, 4-Q

D 1-R, 2-P, 3-Q, 4-S

💡 Short Explanation

Grassland conversion = Beef cattle (R). Pollution = Habitat degradation (P). Soya cultivation = Amazon clearing (Q). Unintentional = Invasive threat (S).

✅ Correct Answer Explanation

Conversion to grasslands (1) is specifically used for beef cattle in the Amazon (R). Pollution (2) is a broader driver of habitat degradation (P). Soya bean cultivation (3) is the mechanism for clearing the Amazon (Q). Unintentional introduction (4) creates invasive threats (S).

❓ Why Other Options Are Incorrect

Other options mismatch the specific outcomes or drivers provided in the chapter.

🎯 Strategy

Used: Option Grouping

Application: Matching cause to the correct textbook-defined outcome.

Final Logic: 1-R, 2-P, 3-Q, 4-S.

🧠 Memory Trick

"Beef-Grassland, Soya-Amazon."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Amazon Deforestation

9 Which of the following historical extinctions or declines is NOT attributed to the transition of human behavior from 'need' to 'greed'?

A Disappearance of the passenger pigeon

B Extinction of Steller's sea cow

C Overharvesting of marine fish populations

D Decline of indigenous cichlid fish in Lake Victoria

💡 Short Explanation

Need to Greed relates to over-exploitation. Steller's, Pigeon, and Marine fish are over-exploitation. Cichlid fish decline is due to Alien Species Invasion (Nile perch).

✅ Correct Answer Explanation

The decline of cichlid fish in Lake Victoria was caused by the introduction of an invasive species (the Nile perch), not by over-exploitation driven by human greed.

❓ Why Other Options Are Incorrect

Options A, B, and C are classic examples of over-exploitation (Greed) in the textbook.

🎯 Strategy

Used: Elimination

Application: Categorizing each event as either "Over-exploitation" or "Alien Invasion."

Final Logic: Cichlid = Alien species.

🧠 Memory Trick

"Cichlid = Alien, Pigeon = Greed."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Resource Over-Exploitation

10 Analyze the following statements about commercially important fish harvesting:
I. It represents a form of over-exploitation by humans.
II. It endangers the continued existence of several marine populations around the world.
III. It leads directly to the co-extinction of plant-pollinator mutualisms. Which statements are logically supported by the text?

A II and III only

B I and II only

C I and III only

D I, II, and III

💡 Short Explanation

Overharvesting is Over-exploitation (I). Overharvesting endangers species (II). Co-extinction (III) is a separate category and not related to fishing.

✅ Correct Answer Explanation

Overharvesting is the standard definition of over-exploitation (I) which puts species at risk (II). Co-extinction is a distinct mechanism in the Evil Quartet, unrelated to commercial fishing; therefore, statement III is logically unsupported.

❓ Why Other Options Are Incorrect

Options including III are incorrect because they conflate unrelated categories of the Evil Quartet.

🎯 Strategy

Used: Elimination

Application: Identifying that Statement III is scientifically and textually distinct from fish over-exploitation.

Final Logic: Fishing = Over-exploitation, not Co-extinction.

🧠 Memory Trick

"Fish = Over-exploitation (Not Co-extinction)."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Resource Over-Exploitation

11 Match the historically extinct animal with its native region or cause of extinction.

List I	List II
1. Dodo	P. Australia
2. Quagga	Q. Russia / Overexploitation
3. Thylacine	R. Mauritius
4. Steller's Sea Cow	S. Africa

A 1-R, 2-S, 3-P, 4-Q

B 1-S, 2-R, 3-Q, 4-P

C 1-R, 2-P, 3-S, 4-Q

D 1-P, 2-S, 3-R, 4-Q

💡 Short Explanation

Dodo (R) = Mauritius. Quagga (S) = Africa. Thylacine (P) = Australia. Steller's (Q) = Russia/Overexploitation.

✅ Correct Answer Explanation

Dodo was endemic to Mauritius (R). The Quagga was from Africa (S). The Thylacine (Tasmanian tiger) was from Australia/Tasmania (P). Steller's sea cow was from the North Pacific/Russia and is a famous case of overexploitation (Q).

❓ Why Other Options Are Incorrect

Incorrect matches of geographic regions and extinction cases.

🎯 Strategy

Used: Option Grouping

Application: Mapping extinct species to their historical range.

Final Logic: 1-R, 2-S, 3-P, 4-Q.

🧠 Memory Trick

"Dodo = Mauritius."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Historical Extinction Examples

12 Sequence the steps that generally lead to the over-exploitation of species like the passenger pigeon.
I. Extinction of the heavily utilized species.
II. Humans depend on nature for basic food and shelter.
III. Human 'need' transitions into commercial 'greed'.
IV. Over-exploitation of the specific natural resource occurs.

A IV → III → II → I

B III → II → I → IV

C II → IV → III → I

D II → III → IV → I

💡 Short Explanation

Need (II). Becomes Greed (III). Leads to Over-exploitation (IV). Leads to Extinction (I).

✅ Correct Answer Explanation

The text describes the process as: Humans initially have a 'need' for nature (II). This need transitions into 'greed' (III), which drives them to over-exploit the resource (IV), eventually causing the extinction of the species (I).

❓ Why Other Options Are Incorrect

Other sequences break the logical chain of human motivation and ecological outcome.

🎯 Strategy

Used: Substitution

Application: Creating a chronological flow based on the "Need vs. Greed" concept in the textbook.

Final Logic: Need -> Greed -> Over-exploit -> Extinct.

🧠 Memory Trick

"Need, Greed, Exploit, Gone."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Resource Over-Exploitation

13 The extinction of over 200 species of cichlid fish in Lake Victoria demonstrates that isolated ecosystems are exceptionally vulnerable to which specific threat?

A Habitat fragmentation

B Over-exploitation

C Deliberate introduction of alien species

D Cultivation of soya beans

💡 Short Explanation

Nile perch = Alien species. Lake Victoria = Isolated ecosystem. Extinction of 200+ cichlids.

✅ Correct Answer Explanation

The introduction of the Nile perch into Lake Victoria is the definitive textbook example of how the "deliberate introduction of alien species" leads to mass extinction in isolated aquatic ecosystems.

❓ Why Other Options Are Incorrect

Options A, B, and D were not the primary cause of the cichlid extinctions in Lake Victoria.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Linking the "Nile perch" example to the category "Alien Species Invasions."

Final Logic: Intro of Nile perch = Alien species.

🧠 Memory Trick

"Lake Victoria = Nile Perch = Alien."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Alien Species Invasions

14 Assess the following statements regarding alien species invasions:
I. They can be introduced unintentionally or deliberately.
II. All introduced alien species eventually turn invasive.
III. The recent illegal introduction of Clarias gariepinus poses a threat to indigenous river catfishes. Which statements are correct?

A I and II only

B II and III only

C I and III only

D I, II, and III

💡 Short Explanation

Intro can be intentional or unintentional (I). NOT all become invasive (II). Clarias is a known threat (III).

✅ Correct Answer Explanation

Alien species are introduced either deliberately (like the Nile perch) or unintentionally (like weeds). However, not all alien species become "invasive" (which refers to species that spread uncontrollably and cause damage); therefore, statement II is false. Statement III accurately reflects the status of Clarias gariepinus.

❓ Why Other Options Are Incorrect

Any option containing II is wrong.

🎯 Strategy

Used: Elimination

Application: Identifying that Statement II is an overgeneralization.

Final Logic: Alien ≠ Always Invasive.

🧠 Memory Trick

"Alien can be harmless."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Alien Species Invasions

15 Which of the following is NOT an indigenous species that is currently threatened or has been driven to extinction by alien invasions?

A Indigenous cichlid fish in Lake Victoria

B Indigenous catfishes in Indian rivers

C Parthenium and Eicchornia

D Native plant species outcompeted by Lantana

💡 Short Explanation

Parthenium and Eichhornia are the invasive weeds. A, B, and D are the native species being threatened. Question asks for the "NOT" (i.e., the invader itself).

✅ Correct Answer Explanation

Parthenium and Eichhornia are the invasive alien weeds, not the native/indigenous species being threatened by alien invasions. The other options list indigenous species impacted by invasive ones.

❓ Why Other Options Are Incorrect

Options A, B, and D are correctly identified as indigenous species negatively impacted by invasive ones.

🎯 Strategy

Used: Odd One Out

Application: Distinguishing between "Invasive Invader" and "Threatened Native."

Final Logic: Invasive species are not native.

🧠 Memory Trick

"Weed = Alien, Not Native."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Alien Species Invasions

16 The proliferation of carrot grass and water hyacinth in native habitats exemplifies how invasive weeds cause environmental damage. This falls under which consequence of the 'Evil Quartet'?

A Alien species causing a decline of indigenous species

B Over-exploitation of commercial flora

C Degradation of habitats by chemical pollution

D Obligatory co-extinction of parasitic weeds

💡 Short Explanation

Weeds = Alien species. Proliferation = Decline of native species. This is exactly the "Alien Species Invasions" category.

✅ Correct Answer Explanation

Invasive alien species (like weeds) spread and outcompete native (indigenous) species, leading to their decline. This is the textbook definition and consequence of "Alien Species Invasions."

❓ Why Other Options Are Incorrect

Options B, C, and D describe other categories or processes not relevant to the proliferation of invasive alien weeds.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Linking the "Invasive Weed" example to its category in the Evil Quartet.

Final Logic: Invasive Weeds = Alien Species Category.

🧠 Memory Trick

"Invasive = Alien."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Alien Species Invasions

17 In which of the following scenarios is co-extinction NOT expected to occur automatically?

A When a highly specific host fish species goes extinct, its specific parasites also die.

B When a plant species in an obligatory coevolved mutualism goes extinct, its pollinator dies.

C When a mammalian species loses its large territory but successfully adapts to a new fragmented habitat.

D When a pollinator goes extinct, the obligate plant species that depends solely on it goes extinct.

💡 Short Explanation

Co-extinction = Obligatory dependency. Adaptation (C) is a survival strategy, not an obligatory dependency extinction. Options A, B, and D describe perfect examples of obligatory co-extinction.

✅ Correct Answer Explanation

Co-extinction occurs only when species have an obligatory association. In Option C, a mammal adapting to habitat fragmentation describes an ecological shift or resilience, not a case where one species is biologically forced to go extinct because its partner did.

❓ Why Other Options Are Incorrect

Options A, B, and D are classic examples of obligatory co-extinction.

🎯 Strategy

Used: Elimination

Application: Differentiating between obligatory dependency (co-extinction) and general habitat survival (resilience).

Final Logic: Co-extinction = Obligatory reliance only.

🧠 Memory Trick

"Obligatory = Co-extinction."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Co-extinction

18 Why does the extinction of a specific host fish invariably lead to the extinction of its parasite assemblage?

A Because the parasites have an obligatory association with that specific host.

B Because the parasites are hunted by the same predators.

C Because the parasites are over-exploited by humans for aquaculture.

D Because the host fish actively protected the parasites from alien species.

💡 Short Explanation

Obligatory association = Absolute reliance. Host gone = Food/Shelter for parasite gone. Result = Parasite dies.

✅ Correct Answer Explanation

Parasites in this context are specialized to live on or within a specific host. Because this is an obligatory association (the parasite cannot survive on any other host), the death of the host automatically seals the fate of the parasite.

❓ Why Other Options Are Incorrect

Option B, C, and D provide explanations that are not biologically relevant to host-parasite obligate relationships.

🎯 Strategy

Used: Substitution

Application: Applying the definition of "obligatory association."

Final Logic: Obligatory = Host-specific survival.

🧠 Memory Trick

"Parasite = Host-dependent."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Co-extinction

19 Match the species interaction with its likelihood of co-extinction as described in the text.

List 1	List 2
1. Coevolved plant-pollinator mutualism	P. Extinction of one invariably leads to extinction of the other
2. Alien predator (Nile perch) and native prey	Q. Introduction leads to extinction of the native prey
3. Host fish and unique parasite assemblage	R. Overharvesting by one endangers the continued existence of the other
4. Humans and commercially important marine fish	S. Extinction of the host seals the same fate for the assemblage

A 1-R, 2-Q, 3-P, 4-S

B 1-S, 2-P, 3-Q, 4-R

C 1-P, 2-R, 3-S, 4-Q

D 1-P, 2-Q, 3-S, 4-R

💡 Short Explanation

Plant-pollinator (P) = Invariable co-extinction. Nile perch (Q) = Predator/Prey extinction. Parasites (S) = Host-extinction fate. Humans/Fish (R) = Overharvesting effect.

✅ Correct Answer Explanation

Plant-pollinator mutualism (1-P) is an obligatory co-extinction. Alien predator-prey interaction (2-Q) leads to the prey's extinction. Host and parasite (3-S) represent co-extinction upon host loss. Humans and marine fish (4-R) exemplify over-exploitation.

❓ Why Other Options Are Incorrect

Mismatched categories and definitions.

🎯 Strategy

Used: Option Grouping

Application: Matching the interaction to its ecological outcome.

Final Logic: 1-P, 2-Q, 3-S, 4-R.

🧠 Memory Trick

"P-Mutualist, S-Parasite."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Co-extinction/Over-exploitation

20 What ecological principle explains the extreme vulnerability of specialized species, such as a plant that relies exclusively on a single insect species for pollination?

A Obligatory co-extinction dynamics

B Species-area relationship

C Latitudinal gradient diversity

D Alien species invasion resistance

💡 Short Explanation

Exclusivity = Obligatory. Reliance = Dependency. Extinction of one = Extinction of the other.

✅ Correct Answer Explanation

When a species is specialized (obligatory mutualist), it cannot survive if its partner species is lost. This precise vulnerability is the foundational concept of "Obligatory co-extinction dynamics."

❓ Why Other Options Are Incorrect

Option B, C, and D are separate ecological concepts unrelated to the extinction risk caused by obligatory mutualism.

🎯 Strategy

Used: Elimination

Application: Connecting the specific example (pollination reliance) to the correct "Evil Quartet" category.

Final Logic: Reliance = Co-extinction.

🧠 Memory Trick

"Obligatory = Dependent."

📚 Class XII – Biology – Chapter: Biodiversity and Conservation – Topic: Co-extinction

CUET UG Biology Booster Test 2-Causes of Species Extinction

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