ORGANISMS AND POPULATION MCQs for NEET UG BIOLOGY — Medium, Page 3

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Understanding +4 | -1

Newly developed pathogens are more damaging to host because host are called

View answer and explanation

Correct option: C

Instant pathogen

The correct answer is not explicitly defined in the options. However, the closest and most logical answer is C (Instant pathogen) because newly developed pathogens are immediately damaging to hosts.

Solution approach

Correct Answer + Core Reason: Instant pathogen. Newly developed pathogens are immediately damaging to hosts.

Step-by-Step Solution:

Step 1: Consider the context: Newly developed pathogens are more damaging because hosts lack immunity.

Step 2: Evaluate the options:
- Distant pathogen: Doesn't relate to the timing of development.
- Chronic pathogen: Implies long-term infection, not necessarily newness.
- Instant pathogen: Suggests immediate effect, aligning with the scenario.
- Genetic improved pathogens: Focuses on pathogen's evolution, not host's response to newness.

Step 3: The term "instant" best describes the immediate impact of a newly developed pathogen on a host lacking prior exposure or immunity.

Why other options are wrong:
- Option A (Distant pathogen): This term doesn't relate to the host's lack of immunity to a new pathogen.
- Option B (Chronic pathogen): This refers to long-term infections, not the initial impact of a new pathogen.
- Option D (Genetic improved pathogens): While genetic improvement can make pathogens more virulent, the question focuses on the host's response to a *new* pathogen, regardless of its genetic makeup.

Key Concepts:
- Pathogen
- Host immunity
- Virulence

Memory Aids:
- Think of "instant" as meaning "immediate impact".

Quick Tips:
- Consider the context of "newly developed" and "more damaging" when choosing the best fit.

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How much percentage of animals on this earth are regulators?

View answer and explanation

Correct option: D

0.01

Option D (0.01) is correct because only a very small percentage of animals are able to maintain a constant internal environment (regulators).

Solution approach

Correct Answer + Core Reason: Only about 0.01% of animals are regulators.

Step-by-Step Solution:

Step 1: Define Regulators: Regulators are organisms that maintain a constant internal environment regardless of external conditions.

Step 2: Explain the rarity of regulation: Maintaining a constant internal environment requires significant energy expenditure.

Step 3: State the percentage: Only a small fraction of animals are true regulators; the percentage is approximately 0.01%.

Why other options are wrong:
- Option A: 0.02 is too high a percentage.
- Option B: 0.03 is too high a percentage.
- Option C: 0.04 is too high a percentage.

Key Concepts:
- Regulation
- Conformation
- Homeostasis

Memory Aids:
- Regulators are rare!

Quick Tips:
- Most animals are conformers, not regulators.

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Assertion: Coral reefs are not found in the
regions from West Bengal to Andhra Pradesh
but are found in Tamil Nadu and on the East
coast of India.

Reason: Corals require low siltation, low fresh
water inflow by rivers, high salinity and optimal
temperature to colonize.

View answer and explanation

Correct option: A

If both Assertion and Reason are true and
Reason is the correct explanation of Assertion

Option A is correct because the assertion and reason are both true, and the reason correctly explains why coral reefs are not found in certain regions.

Solution approach

Correct Answer + Core Reason: If both Assertion and Reason are true and Reason is the correct explanation of Assertion. Coral reefs require specific environmental conditions that are not met in the regions mentioned in the assertion, as stated in the reason.

Step-by-Step Solution:

Step 1: Analyze the Assertion: The assertion states that coral reefs are not found in regions from West Bengal to Andhra Pradesh but are found in Tamil Nadu and on the East coast of India. This is generally true due to varying environmental conditions.

Step 2: Analyze the Reason: The reason states that corals require low siltation, low fresh water inflow by rivers, high salinity, and optimal temperature to colonize. This is also true; these are the key factors for coral reef development.

Step 3: Determine the relationship: The reason directly explains why the assertion is true. The areas mentioned in the assertion lack the optimal conditions described in the reason.

Step 4: Conclusion: Both the assertion and reason are true, and the reason is the correct explanation of the assertion.

Why other options are wrong:
- Option B: While both statements are true, the reason *does* explain the assertion.
- Option C: The assertion is true, so this option is incorrect.
- Option D: Both the assertion and reason are true, so this option is incorrect.

Key Concepts:
- Coral reef ecology
- Environmental factors affecting coral growth
- Assertion-Reason type questions

Memory Aids:
- Remember the key requirements for coral reef growth: low siltation, low freshwater inflow, high salinity, and optimal temperature.

Quick Tips:
- Carefully analyze both the assertion and reason independently before considering their relationship. Look for direct causal links between the two statements.

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How does a kangaroo rat cope with the North American desert environment?

View answer and explanation

Correct option: D

1 and 2

The correct answer is D (1 and 2) because kangaroo rats survive in the desert by oxidizing stored fat for water and minimizing water loss through excretion.

Solution approach

Correct Answer + Core Reason: 1 and 2. Kangaroo rats have adaptations for water conservation in the desert.

Step-by-Step Solution:

Step 1: Understand the desert environment: Deserts are characterized by scarcity of water.

Step 2: Consider kangaroo rat adaptations: Kangaroo rats are well-adapted to desert life.

Step 3: Analyze option 1: Internal oxidation of stored fat produces metabolic water, helping them survive without drinking water.

Step 4: Analyze option 2: They excrete highly concentrated urine to minimize water loss.

Step 5: Analyze option 3: Migration is not a primary strategy for kangaroo rats.

Step 6: Combine correct adaptations: Options 1 and 2 are both valid adaptations.

Why other options are wrong:
- Option A: This is only one of the adaptations. It's incomplete.
- Option B: This is only one of the adaptations. It's incomplete.
- Option C: Kangaroo rats do not primarily rely on migration to cope with the desert environment.

Key Concepts:
- Desert adaptations
- Water conservation
- Metabolic water
- Excretion

Memory Aids:
- Remember that desert animals need to conserve water.

Quick Tips:
- Consider multiple adaptations when answering questions about survival in extreme environments.

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Term ‘ecology’ was given by

View answer and explanation

Correct option: C

Haeckel

Option C (Haeckel) is correct because Ernst Haeckel coined the term 'ecology' in 1866.

Solution approach

Correct Answer + Core Reason: Haeckel. Ernst Haeckel coined the term ecology.

Step-by-Step Solution:

Step 1: Recall the History of Ecology: Ecology as a scientific discipline was formally defined in the late 19th century.

Step 2: Identify the Founder: Ernst Haeckel, a German biologist, is credited with coining the term "ecology" in 1866.

Step 3: Conclusion: The term 'ecology' was given by Haeckel.

Why other options are wrong:
- Option A (Reiter): Reiter is not generally credited with coining the term ecology.
- Option B (Cuvier): Cuvier was a prominent figure in paleontology and comparative anatomy, but not ecology.
- Option D (Malthus): Malthus is known for his work on population growth, but not for coining the term ecology.

Key Concepts:
- History of Ecology
- Ernst Haeckel
- Definition of Ecology

Memory Aids:
- Haeckel = Ecology (associate the names)

Quick Tips:
- Remember that Haeckel is the founder of ecology.

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In 2005, for each of the 14 million people present in a country, 0.028 were born and 0.008 died during the year. Using exponential equation, the number of people present in 2015 is predicted as:

View answer and explanation

Correct option: B

17 millions

Option B (17 millions) is correct because the exponential growth equation is used to project the population size in 2015 based on the birth and death rates in 2005. The calculation involves using the formula

N_t = N_0 * e^{rt}

, where

N_0

is the initial population,

r

is the intrinsic rate of increase,

t

is the time, and

N_t

is the population at time t.

Solution approach

Correct Answer + Core Reason: 17 millions. Exponential growth is calculated using the formula $N_t = N_0 * e^{rt}$ .

Step-by-Step Solution:
Step 1: Identify the initial population ( $N_0$ ): 14 million.
Step 2: Calculate the intrinsic rate of increase (r): $r = birth\ rate - death\ rate = 0.028 - 0.008 = 0.02$
Step 3: Identify the time period (t): 2015 - 2005 = 10 years.
Step 4: Apply the exponential growth equation: $N_t = N_0 * e^{rt} = 14 * e^{(0.02 * 10)}$
Step 5: Calculate $e^{0.2} \approx 1.2214$
Step 6: Calculate $N_t = 14 * 1.2214 \approx 17.1$
Step 7: Round to the nearest million: 17 million.

Why other options are wrong:
- Option A: 25 millions is an overestimate. It likely involves an incorrect calculation or misunderstanding of the exponential growth formula.
- Option C: 20 millions is an overestimate. It likely involves an incorrect calculation or misunderstanding of the exponential growth formula.
- Option D: 18 millions is an overestimate. It likely involves an incorrect calculation or misunderstanding of the exponential growth formula.

Key Concepts:
- Exponential growth
- Intrinsic rate of increase
- Population dynamics

Memory Aids:
- $N_t = N_0 * e^{rt}$ (Remember the formula for exponential growth)

Quick Tips:
- Be careful with the units and time period. Ensure you use the correct intrinsic rate of increase.

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Conformers are inactive in adverse conditions due to

View answer and explanation

Correct option: C

Inability to maintain homeostasis

Option C (Inability to maintain homeostasis) is correct because conformers do not regulate their internal environment and are thus inactive in adverse conditions.

Solution approach

Correct Answer + Core Reason: Inability to maintain homeostasis. Conformers lack the ability to regulate their internal environment, making them vulnerable in adverse conditions.

Step-by-Step Solution:

Step 1: Define conformers.\nConformers are organisms that do not actively regulate their internal environment; their internal conditions vary with external conditions.

Step 2: Relate conformers to homeostasis.\nHomeostasis is the ability to maintain a stable internal environment despite external changes.

Step 3: Determine the impact of adverse conditions.\nIn adverse conditions, the inability to maintain homeostasis leads to inactivity or death in conformers.

Why other options are wrong:
- Option A: Inability to move might be a consequence of not maintaining homeostasis, but it's not the primary reason for inactivity.
- Option B: Inability to digest properly might be a consequence of not maintaining homeostasis, but it's not the primary reason for inactivity.
- Option D: Ability to maintain homeostasis is the opposite of what conformers can do.

Key Concepts:
- Conformers
- Regulators
- Homeostasis
- Environmental adaptation

Memory Aids:
- Conform = Change with the environment
- Regulate = Maintain a constant internal environment

Quick Tips:
- Understand the difference between conformers and regulators.

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Human liverfluke (a trematode parasite) depends on which two intermediate hosts I. Snail II. Fish III. Pig IV. Mosquito Choose the correct combination

View answer and explanation

Correct option: A

I and II

Option A (I and II) is correct because the human liver fluke requires a snail and a fish as intermediate hosts.

Solution approach

Correct Answer + Core Reason: The liver fluke uses snails and fish as intermediate hosts.

Step-by-Step Solution:

Step 1: Describe the life cycle of the liver fluke: The human liver fluke has a complex life cycle involving multiple hosts.

Step 2: Identify the intermediate hosts: The first intermediate host is a snail, and the second intermediate host is a fish.

Step 3: Confirm the answer: The correct combination is snail (I) and fish (II).

Why other options are wrong:
- Option B: Fish is an intermediate host, but pig is not.
- Option C: Neither pig nor mosquito are intermediate hosts for the liver fluke.
- Option D: Mosquito is not an intermediate host for the liver fluke.

Key Concepts:
- Parasite life cycle
- Intermediate host
- Liver fluke

Memory Aids:
- Remember the snail and fish in the liver fluke's life cycle.

Quick Tips:
- Understand the life cycles of common parasites.

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Ecology is basically concerned with how many levels?

View answer and explanation

Correct option: C

Four

Option C (Four) is correct because ecology is concerned with four levels of biological organization: organism, population, community, and ecosystem.

Solution approach

Correct Answer + Core Reason: Four. Ecology is concerned with four levels: organism, population, community, and ecosystem.

Step-by-Step Solution:

Step 1: Recall the Levels of Ecological Study: Consider the different levels at which ecological studies are conducted.

Step 2: List the Levels: The four basic levels are:
- Organism
- Population
- Community
- Ecosystem

Step 3: Conclusion: Ecology is basically concerned with four levels.

Why other options are wrong:
- Option A: One is incorrect because ecology studies more than just individual organisms.
- Option B: Three is incorrect because ecology studies more than just three levels (organism, population, community, and ecosystem).
- Option D: Five is incorrect because while there are more levels in the overall biological hierarchy (e.g., biome, biosphere), ecology primarily focuses on these four levels.

Key Concepts:
- Levels of Ecological Organization
- Organism
- Population
- Community
- Ecosystem

Memory Aids:
- Remember the order: Organism, Population, Community, Ecosystem. Think of it as building from the smallest to the largest.

Quick Tips:
- Focus on the core levels of ecological study.

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Behavioural adaptation to environment in desert lizards are
I. Burrowing soil
II. Losing heat during high temperature
III. Active during morning and evening
IV. Insulating body due to thick fatty dermis
Select the correct pair

View answer and explanation

Correct option: A

I and III

Option A (I and III) is correct because burrowing in soil and being active during morning and evening are behavioral adaptations to avoid extreme desert temperatures.

Solution approach

Correct Answer + Core Reason: I and III. Burrowing and being active during cooler times are behavioral adaptations to avoid heat.

Step-by-Step Solution:

Step 1: Analyze each statement in the context of desert lizard adaptations.

Step 2: Evaluate each statement:
- I. Burrowing soil: Allows lizards to escape extreme heat by staying underground.
- II. Losing heat during high temperature: This is a physiological response, not a behavioral adaptation. Lizards try to *avoid* high temperatures.
- III. Active during morning and evening: Lizards are often active during cooler parts of the day (crepuscular) to avoid midday heat.
- IV. Insulating body due to thick fatty dermis: This is a physiological adaptation, not behavioral.

Step 3: Identify the behavioral adaptations: I and III.

Why other options are wrong:
- Option B (III and IV): IV is a physiological adaptation, not behavioral.
- Option C (I and II): II is incorrect as lizards try to avoid losing heat during high temperatures by avoiding those temperatures altogether.
- Option D (II and IV): Both II and IV are physiological adaptations, not behavioral.

Key Concepts:
- Behavioral adaptation
- Physiological adaptation
- Desert adaptations

Memory Aids:
- Behavioral adaptations are actions the animal *does* to survive.

Quick Tips:
- Distinguish between behavioral (actions) and physiological (internal processes) adaptations.

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Assertion: It drains off oxygen from water and
is seen growing in standing water with respect
to Eichorrnia.

Reason: It is an indigenous species of our
country.

View answer and explanation

Correct option: C

If Assertion is true but Reason is false

Option C is correct because the assertion is true (Eichhornia drains oxygen from water), but the reason is false (Eichhornia is not an indigenous species).

Solution approach

Correct Answer + Core Reason: If Assertion is true but Reason is false. Eichhornia (water hyacinth) is an invasive species that depletes oxygen, but it's not native to the country.

Step-by-Step Solution:

Step 1: Analyze the Assertion: Eichhornia crassipes (water hyacinth) is known for its rapid growth and ability to cover water surfaces. This dense coverage blocks sunlight and reduces oxygen levels in the water, harming aquatic life. Therefore, the assertion is true.

Step 2: Analyze the Reason: Eichhornia is *not* an indigenous species of most countries where it is a problem. It is native to South America and has been introduced to many other regions, where it has become an invasive species. Therefore, the reason is false.

Step 3: Determine the relationship: The assertion and reason are not directly related. The fact that Eichhornia drains oxygen from the water is independent of its origin.

Why other options are wrong:
- Option A: This is incorrect because the reason is false.
- Option B: This is incorrect because the reason is false.
- Option D: This is incorrect because the assertion is true.

Key Concepts:
- Invasive species: Species that are introduced to a new environment and cause harm.
- Environmental impact of invasive species.
- Oxygen depletion in aquatic ecosystems.
- Eichhornia crassipes (water hyacinth)

Memory Aids:
- Remember that Eichhornia is an invasive species, not a native one.

Quick Tips:
- Be aware of common examples of invasive species and their impacts.

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If ‘8’ Drosophila in a laboratory population of ‘80’ died during a week, the death rate in the population is ___________ individuals per Drosophila per week.

View answer and explanation

Correct option: B

0.1

Option B (0.1) is correct because the death rate is calculated by dividing the number of deaths by the total population size (8/80 = 0.1).

Solution approach

Correct Answer + Core Reason: 0.1. The death rate is the number of deaths divided by the total population.

Step-by-Step Solution:
Step 1: Identify the number of deaths: 8 Drosophila.
Step 2: Identify the total population: 80 Drosophila.
Step 3: Calculate the death rate: $Death\ Rate = \frac{{Number\ of\ Deaths}}{{Total\ Population}}$
Step 4: Substitute the values: $Death\ Rate = \frac{{8}}{{80}}$
Step 5: Calculate the death rate: $Death\ Rate = 0.1$

Why other options are wrong:
- Option A: Zero is incorrect because there were deaths in the population.
- Option C: 10 is the reciprocal of the death rate, not the death rate itself.
- Option D: 1 is incorrect. It's not a logical calculation based on the given data.

Key Concepts:
- Death rate
- Population dynamics

Memory Aids:
- Death Rate = Deaths / Population

Quick Tips:
- Ensure you are dividing the number of deaths by the correct total population size.

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…A… regulators are able to maintain homeostasis by means which ensures constant body temperature, constant osmotic concentration, etc. All …B… and …C…. and is very few lower vertebrate and invertebrate species are indeed capable of such regulation (thermoregulation and osmoregulation)
Evolutionary biologists believe that the ‘success’ of mammals is largely due to their ability to maintain a constant body …D… and thrive whether they live in Antarctica or in the Sahara desert
Choose the correct option for A, B, C and D

View answer and explanation

Correct option: C

A-Physiological, B-bird, C-mammals, D-temperature

Option C (A-Physiological, B-bird, C-mammals, D-temperature) is correct because physiological regulators maintain homeostasis, and birds and mammals are known for thermoregulation.

Solution approach

Correct Answer + Core Reason: A-Physiological, B-bird, C-mammals, D-temperature. Physiological mechanisms enable homeostasis in birds and mammals, maintaining constant body temperature.

Step-by-Step Solution:

Step 1: Analyze the context of the passage.\nThe passage discusses homeostasis and thermoregulation/osmoregulation.

Step 2: Identify the type of regulation.\nHomeostasis is maintained by physiological processes, not behavioral ones.

Step 3: Identify the organisms capable of thermoregulation/osmoregulation.\nBirds and mammals are well-known for their ability to regulate body temperature.

Step 4: Identify the parameter being regulated.\nThe passage explicitly mentions constant body temperature.

Why other options are wrong:
- Option A: Behavioral regulation is a component of homeostasis, but the blank requires the primary type of regulation. Also, vertebrates and invertebrates is too broad.
- Option B: Behavioral regulation is a component of homeostasis, but the blank requires the primary type of regulation.
- Option D: Behavioral regulation is a component of homeostasis, but the blank requires the primary type of regulation. Morphology is not the parameter being regulated.

Key Concepts:
- Homeostasis
- Thermoregulation
- Osmoregulation
- Physiological regulation

Memory Aids:
- Physiological = Internal processes
- Behavioral = Actions

Quick Tips:
- Pay attention to the context of the passage to determine the correct answer.

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Root cap is not found in

View answer and explanation

Correct option: C

Hydrophytes

Option C (Hydrophytes) is correct because root caps are often reduced or absent in hydrophytes due to the readily available water.

Solution approach

Correct Answer + Core Reason: Hydrophytes. Root cap is not found in Hydrophytes.

Step-by-Step Solution:

Step 1: Define root cap.\nA root cap is a protective layer of cells covering the tip of a root.

Step 2: Explain the function of root cap.\nThe root cap protects the apical meristem from damage as the root grows through the soil.

Step 3: Root cap in hydrophytes.\nHydrophytes, plants that grow in water, often have reduced or absent root caps because the roots don't need as much protection in the soft, watery environment.

Why other options are wrong:
- Option A: Mesophytes typically have well-developed root caps.
- Option B: Xerophytes typically have well-developed root caps to aid in water absorption in dry conditions.
- Option D: Halophytes, plants that grow in saline conditions, typically have root caps.

Key Concepts:
- Root cap
- Plant adaptations
- Hydrophytes
- Mesophytes
- Xerophytes
- Halophytes

Memory Aids:
- Hydrophytes live in water, so their roots don't need as much protection.

Quick Tips:
- Consider the environment in which the plant grows when determining the presence or absence of a root cap.

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Introduced plants in new localities must show adaptations called

View answer and explanation

Correct option: B

Acclimatization

Option B (Acclimatization) is correct because acclimatization refers to the physiological adjustments that organisms make to new environmental conditions, allowing them to survive in new localities.

Solution approach

Correct Answer + Core Reason: Acclimatization. This is the process of an organism adjusting to a new environment.

Step-by-Step Solution:
Step 1: Define the terms: Selection (natural selection leading to adaptation over generations), Acclimatization (short-term physiological adjustments), Modification (general term for changes), Propagation (reproduction).
Step 2: Consider introduced plants in a new locality. They need to adjust to the immediate environmental conditions to survive.
Step 3: Acclimatization is the process that allows them to make these immediate adjustments.

Why other options are wrong:
- Option A: Selection is a long-term evolutionary process, not an immediate adaptation to a new environment.
- Option C: Modification is a general term and doesn't specifically refer to the physiological adjustments needed for survival in a new environment.
- Option D: Propagation refers to reproduction, not the initial adaptation to a new environment.

Key Concepts:
- Acclimatization
- Adaptation

Memory Aids:
- Acclimatization = Adjustment to Climate

Quick Tips:
- Think of acclimatization as the \"first aid\" an organism needs in a new environment.

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Population is said to be mature or stable, when

View answer and explanation

Correct option: B

Growth rate being almost zero

Option B (Cattle and cattle egret – Mutualism) is the wrong match because the relationship between cattle and cattle egret is commensalism, not mutualism. The egret benefits by feeding on insects stirred up by the cattle, while the cattle are neither helped nor harmed.

Solution approach

Correct Answer + Core Reason: Cattle and cattle egret – Mutualism. This is a commensal relationship, not mutualistic.

Step-by-Step Solution:

Step 1: Define Commensalism: One organism benefits, and the other is neither harmed nor helped.

Step 2: Define Mutualism: Both organisms benefit.

Step 3: Define Amensalism: One organism is harmed, and the other is unaffected.

Step 4: Define Competition: Both organisms are harmed.

Step 5: Clownfish and sea anemone: Commensalism (clownfish gets protection, anemone is unaffected).

Step 6: Penicillium and Staphylococcus: Amensalism (Penicillium inhibits Staphylococcus growth).

Step 7: Abingdon tortoise and goat: Competition (both compete for the same resources).

Step 8: Cattle and cattle egret: Commensalism (egret benefits by eating insects stirred up by cattle; cattle are unaffected).

Why other options are wrong:
- Option A: Clown fish and sea anemone is a correct example of commensalism.
- Option C: Penicillium and Staphylococcus is a correct example of amensalism.
- Option D: Abingdon tortoise and goat is a correct example of competition.

Key Concepts:
- Commensalism
- Mutualism
- Amensalism
- Competition

Memory Aids:
- Commensalism: \"one benefits, other is so-so\".
- Mutualism: \"both benefit, it's a win-win\".

Quick Tips:
- Understand the different types of species interactions and examples of each.

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Niche overlap indicates

View answer and explanation

Correct option: C

Sharing of one or more resources between the two species

Option C (Sharing of one or more resources between the two species) is correct because niche overlap occurs when two or more species utilize the same resources, leading to potential competition.

Solution approach

Correct Answer + Core Reason: Sharing of one or more resources between the two species. Niche overlap indicates resource sharing.

Step-by-Step Solution:

Step 1: Define Niche. An ecological niche is the role and position a species has in its environment.

Step 2: Define Niche Overlap. Niche overlap occurs when two or more species use the same resources (e.g., food, habitat) in the same area.

Step 3: Analyze the options:
- A. Active cooperation between two species: This describes mutualism, not niche overlap.
- B. Two different parasites on the same host: This is a specific type of interaction, but not the general definition of niche overlap.
- C. Sharing of one or more resources between the two species: This is the correct definition of niche overlap.
- D. Mutualism between two species: This is a different type of interaction where both species benefit.

Why other options are wrong:
- Option A: Cooperation is mutualism, not niche overlap.
- Option B: Parasitism is a specific interaction, not the general definition of niche overlap.
- Option D: Mutualism is a different type of interaction where both species benefit.

Key Concepts:
- Niche: The role and position a species has in its environment.
- Niche Overlap: Sharing of resources between species.

Memory Aids:
- Think of two people trying to occupy the same seat - they are overlapping in their "niche".

Quick Tips:
- Niche overlap often leads to competition between species.

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Choose the wrong statements
I. Two species may not live in same habitat
II. The more dissimilar the niches of two species the stronger is their competition
III. Two species can occupy the same niche in geographical area
IV. No two species may occupy the same ecosystem
The correct option is

View answer and explanation

Correct option: B

II, III and IV

Option B (II, III and IV) is correct because statements II, III, and IV are incorrect. Two species *can* live in the same habitat, the more dissimilar the niches the *weaker* the competition, two species *cannot* occupy the same niche, and two species *can* occupy the same ecosystem.

Solution approach

Correct Answer + Core Reason: II, III and IV. These statements are incorrect regarding species interactions and niches.

Step-by-Step Solution:

Step 1: Analyze Statement I. Two species may not live in same habitat. This statement is incorrect. Many species share the same habitat.

Step 2: Analyze Statement II. The more dissimilar the niches of two species the stronger is their competition. This statement is incorrect. The more similar the niches, the stronger the competition.

Step 3: Analyze Statement III. Two species can occupy the same niche in geographical area. This statement is incorrect. This violates the competitive exclusion principle.

Step 4: Analyze Statement IV. No two species may occupy the same ecosystem. This statement is incorrect. Many species can occupy the same ecosystem, but they usually have different niches.

Step 5: Identify the wrong statements. Statements II, III, and IV are incorrect.

Why other options are wrong:
- Option A: Includes statement I, which is correct.
- Option C: Includes statement I, which is correct.
- Option D: Only includes statements III and IV, missing statement II.

Key Concepts:
- Habitat: The natural environment where an organism lives.
- Niche: The role and position a species has in its environment.
- Competitive Exclusion Principle: Two species cannot occupy the same niche in the same area.

Memory Aids:
- Remember that species can share habitats but not niches.

Quick Tips:
- Understand the competitive exclusion principle and its implications for species interactions.

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