CUET UG Biology Booster Test 3 Evidences for Biological Evolution -

🚀

CUET UG Biology Booster Test 3 Evidences for Biological Evolution

⏱️ 30 Minutes

❓ 20 Questions

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

CUET UG Biology Booster Test 3 Evidences for Biological Evolution

1 / 20

QUESTION 1 OF 20

Consider the following analytical statements regarding paleontological evidence:
I. Fossils in deeper, older sedimentary layers will generally represent life-forms more distinct from modern organisms than fossils in shallower layers.
II. The absence of a specific fossil in a particular sedimentary layer definitively proves that the organism had not yet evolved.
III. Paleontological evidence proves that the diversity of life was always the same since creation.
IV. The geological history of earth closely correlates with the biological history of earth. Which statements are correct based on evolutionary theory?

Answer Review

1 Consider the following analytical statements regarding paleontological evidence:
I. Fossils in deeper, older sedimentary layers will generally represent life-forms more distinct from modern organisms than fossils in shallower layers.
II. The absence of a specific fossil in a particular sedimentary layer definitively proves that the organism had not yet evolved.
III. Paleontological evidence proves that the diversity of life was always the same since creation.
IV. The geological history of earth closely correlates with the biological history of earth. Which statements are correct based on evolutionary theory?

A I and IV only

B II and III only

C I, II, and IV

D I, III, and IV

💡 Short Explanation

Deeper layers are older and contain ancestral life forms. Fossil absence does not prove non-existence (fossilization is rare/chance). Geological history provides the timeline for biological evolution.

✅ Correct Answer Explanation

�� Deeper layers are geologically older; organisms found there are more ancestral, thus more distinct from current life (I). The correlation between geological strata and biological succession is a fundamental proof of evolution (IV). Statement II is incorrect because fossils only represent a small fraction of extinct life (fossilization is a chance event). Statement III is the direct opposite of what the fossil record proves.

❓ Why Other Options Are Incorrect

Option B → II is incorrect because absence is not proof of non-existence, and III is factually false regarding evolutionary theory.
Option C → II is incorrect as explained above.
Option D → III is incorrect as it contradicts the evidence of changing diversity over time.

🎯 Strategy

Used: Elimination

Application: Eliminate options containing III (false). Between I, II, and IV, identify II as an absolute claim (absence = proof) which is scientifically incorrect.

Final Logic: Only statements I and IV are consistent with established evolutionary evidence.

🧠 Memory Trick

"Deeper = Older; Absence ≠ Absence of life."

📚 Evolution – Topic: Paleontological Evidence

2 If an entirely new, deeply buried sedimentary layer is discovered containing only unicellular fossil impressions, what can be logically deduced about the geological period of that sediment?

A It must have formed during a recent post-industrial era.

B It likely represents a very early epoch before complex multicellular life-forms arose.

C It indicates that multi-cellular organisms experienced a rapid mass extinction.

D It proves that sedimentary layers form randomly regardless of geological time.

💡 Short Explanation

Life forms are restricted to specific time-spans. Complex life (multicellular) appeared much later in Earth's history. Unicellular organisms characterize the early history of life.

✅ Correct Answer Explanation

�� Evolutionary history shows a progression from simple, unicellular organisms to complex multicellular life. Finding a layer containing only unicellular life impressions indicates an age corresponding to the early Earth's history (Precambrian era), long before complex eukaryotes or multicellular life diversified.

❓ Why Other Options Are Incorrect

Option A → Recent eras contain fossils of modern life.
Option C → Mass extinction would show both multicellular fossils and unicellular ones.
Option D → Sedimentary layers follow a chronological order (stratigraphy).

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Match the biological level (unicellular) with the geological era (early/primitive).

Final Logic: Simple life predates complex life in the geological timeline.

🧠 Memory Trick

"Simple life = Early Earth."

📚 Evolution – Topic: Sedimentary Layer Study

3 Which of the following is NOT a logical consequence of applying radioactive-dating procedures to fossil records?

A It allows scientists to assign an absolute numerical age to a fossil, replacing purely relative layering methods.

B It confirms that life-forms have arisen at different distinct times in the history of the earth.

C It relies on the unchanging decay rates of elements found within or around the fossils.

D It calculates the age of fossils by counting the accumulation of environmental soot on the rock surfaces.

💡 Short Explanation

Radioactive dating uses isotopic decay. Soot accumulation is irrelevant to geological dating. Absolute dating is the primary purpose of this technique.

✅ Correct Answer Explanation

�� Radioactive dating measures the ratio of radioactive parent isotopes to stable daughter isotopes. It has absolutely nothing to do with "environmental soot," which is a surface-level phenomenon related to pollution studies (industrial melanism), not deep-time geochronology.

❓ Why Other Options Are Incorrect

Option A → This describes the benefit of absolute dating.
Option B → Chronological dating confirms the sequence of life.
Option C → Decay rates are indeed constant and physical.

🎯 Strategy

Used: Odd One Out

Application: D describes a process related to smoke/pollution (soot), while the others describe geological/radioactive principles.

Final Logic: Soot accumulation is not a scientific method for fossil dating.

🧠 Memory Trick

"Radioactive ≠ Soot (Soot is for Moths)."

📚 Evolution – Topic: Radioactive Dating Principles

4 Arrange the conceptual milestones in establishing geological time spans using biological evidence:
I. Identifying that new forms of life arose at different times in earth's history.
II. Observing a cross-section of earth's crust to find layered sediments.
III. Calculating specific fossil ages using radioactive-dating methods.
IV. Discovering that certain life forms are strictly restricted to certain sedimentary layers.

A II, IV, I, III

B II, IV, III, I

C IV, II, III, I

D I, II, IV, III

💡 Short Explanation

Observe strata (II) -> Stratigraphic sequence (IV) -> Absolute age dating (III) -> Conclusion on evolution (I).

✅ Correct Answer Explanation

�� One must first observe the physical cross-section (II). Then, one notices the restricted distribution of fossils in those layers (IV). To turn this relative order into an absolute timeline, radioactive dating is applied (III). Finally, these data confirm the theory that life arose sequentially over time (I).

❓ Why Other Options Are Incorrect

Option A → Calculates ages (III) before the conclusion (I) is fine, but the order of observing restricted forms (IV) should lead to the need for dating (III).
Option C → IV must follow the physical observation of the cross-section (II).
Option D → The conclusion (I) is the result, not the beginning of the research.

🎯 Strategy

Used: Option Grouping

Application: Order: Observation -> Restriction Observation -> Radioactive dating -> Conclusion.

Final Logic: The sequence represents the standard scientific method of paleontology.

🧠 Memory Trick

"Observe -> Restrict -> Date -> Conclude."

📚 Evolution – Topic: Geological Time Spans

5 Match the evolutionary concept to its underlying mechanism or example:

Column I	Column II
I. Homology	P. Sweet potato and potato
II. Analogy	Q. Driven by adaptations to different needs from a common ancestor
III. Divergent Evolution	R. Wings of butterfly and birds
IV. Convergent Evolution	S. Common ancestry indicated by similar structural patterns

A I-S, II-R, III-Q, IV-P

B I-Q, II-S, III-P, IV-R

C I-S, II-P, III-Q, IV-R

D I-R, II-S, III-P, IV-Q

💡 Short Explanation

Homology: Structural patterns (S). Analogy: Butterfly/Bird wings (R). Divergent: Adaptation to different needs from ancestor (Q). Convergent: Sweet potato/potato (P).

✅ Correct Answer Explanation

�� Homology (I) is identified by structural patterns (S). Analogy (II) includes structures like bird/butterfly wings (R). Divergent evolution (III) is driven by different needs (Q). Convergent evolution (IV) results in analogies like the sweet potato/potato (P).

❓ Why Other Options Are Incorrect

Option B, C, D → All misalign the definitions and examples provided in the NCERT text.

🎯 Strategy

Used: Substitution

Application: Validate pairings: Homology (I) is clearly linked to Structural Patterns (S). Only A starts with I-S.

Final Logic: A is the only combination where all terms are correctly defined.

🧠 Memory Trick

"Homology=Structure; Analogy=Wings; Divergent=Ancestor adaptation."

📚 Evolution – Topic: Morphological Homology/Analogy

6 Analyzing figure, the structural similarity of the humerus, radius, and ulna across these diverse mammals mathematically relates to genetic inheritance. What evolutionary principle prevents these bones from being perfectly identical in size and shape across the species?

A Convergent evolution driving structural convergence.

B Adaptations to different environmental needs causing divergent evolution.

C A complete lack of shared genetic basis.

D Spontaneous generation of localized mutations isolated to single individuals.

💡 Short Explanation

Homology implies common ancestor. Adaptation to specific environments (flying, swimming, etc.) modifies morphology. This modification is the "divergence" in divergent evolution.

✅ Correct Answer Explanation

�� While mammals share the same bone architecture (due to common descent), the "selective pressure" of their unique lifestyles (e.g., flight for bats, swimming for whales) acts upon these limbs. This forces the structures to adapt, changing their size and shape to optimize function. This is precisely the mechanism of divergent evolution.

❓ Why Other Options Are Incorrect

Option A → Convergent evolution leads to similarity, not difference.
Option C → They share a genetic basis (this is the definition of homology).
Option D → Evolution acts on populations, not isolated spontaneous generation.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Identify the mismatch between shared ancestry and phenotypic difference as a core feature of divergent evolution.

Final Logic: B explains why homologous structures become morphologically distinct.

🧠 Memory Trick

"Shared Bones + Different Life = Divergent."

📚 Evolution – Topic: Divergent Evolution

7 Which of the following analytical statements is NOT a valid interpretation of convergent evolution?

A It demonstrates that similar habitats can apply similar selective pressures to unrelated organisms.

B It results in structures that, despite superficial similarities, lack deep anatomical correspondence.

C It proves that structural analogy is entirely dependent on recent shared ancestry.

D It explains why octopus eyes and mammal eyes function similarly despite different origins.

💡 Short Explanation

Convergent evolution = Unrelated organisms. Analogy = NOT dependent on shared ancestry. Homology = Dependent on shared ancestry.

✅ Correct Answer Explanation

�� Convergent evolution is specifically defined by the independent evolution of similar traits in unrelated organisms. If it depended on shared ancestry, it would be homology. Therefore, C is fundamentally false and the "NOT valid" statement.

❓ Why Other Options Are Incorrect

Option A → Similar environments drive convergent evolution.
Option B → Analogous structures are superficial, not deeply homologous.
Option D → This is a valid example of convergent evolution.

🎯 Strategy

Used: Elimination

Application: Identify the definition of convergent evolution. C is the only option that directly contradicts it.

Final Logic: Analogy arises despite a lack of recent shared ancestry.

🧠 Memory Trick

"Convergent = Unrelated = NO shared ancestry."

📚 Evolution – Topic: Convergent Evolution

8 An evolutionary biologist examines a bird wing and a butterfly wing. At a microscopic tissue level, they are fundamentally different, yet aerodynamically they solve the same physical problem. This phenomenon indicates that:

A Nature can select for functionally similar adaptive features in entirely different biological groups towards the same goal.

B The genetic code for wing development in insects was horizontally transferred to birds.

C Morphological homology inevitably leads to anatomical analogy over millions of years.

D Birds and insects share an immediate winged ancestor.

💡 Short Explanation

Analogous structures evolve for the same function. Butterflies (insects) and birds (vertebrates) have different origins. Environment selects for the physical necessity of flight.

✅ Correct Answer Explanation

�� This is a classic demonstration of convergent evolution. The "problem" to be solved is flight. Different groups (birds and insects) evolved "solutions" (wings) that look similar for the purpose of the same function, despite being anatomically unrelated.

❓ Why Other Options Are Incorrect

Option B → Horizontal gene transfer of complex limb development is not a standard evolutionary process.
Option C → Homology and analogy are distinct, not stages of each other.
Option D → They are extremely distant groups; they do not share an immediate winged ancestor.

🎯 Strategy

Used: Substitution

Application: Replace "Aerodynamic problem" with "Environmental Pressure." Environmental pressure selects for functional solutions.

Final Logic: A accurately captures the selective mechanism behind convergence.

🧠 Memory Trick

"Same function + Different group = Convergent evolution."

📚 Evolution – Topic: Convergent Evolution

9 In figure the thorn of Bougainvillea and the tendril of Cucurbita arise from the same axillary bud position on the stem. How does this specific botanical observation analytically confirm homology rather than analogy?

A Because their identical function proves they evolved to meet the same environmental challenge.

B Because sharing the same fundamental anatomical origin (axillary bud) demonstrates common ancestry despite diverging functions.

C Because they both undergo photosynthesis in identically structured mesophyll cells.

D Because neither structure is necessary for the plant's survival in a competitive environment.

💡 Short Explanation

Homology = Same origin (axillary bud). Analogy = Same function. These share origin, so they are homologous.

✅ Correct Answer Explanation

�� Anatomical origin is the diagnostic test for homology. By tracing both thorns and tendrils back to the axillary bud, the researcher identifies them as modified branches (stem origin). This confirms that they are the "same" structure adapted to different purposes, which is the definition of homologous structures.

❓ Why Other Options Are Incorrect

Option A → Shared function would imply analogy.
Option C → Neither structure is primarily photosynthetic in the way leaf mesophyll is.
Option D → Both are highly necessary survival structures.

🎯 Strategy

Used: Elimination

Application: Filter for "Common Ancestry/Origin" vs "Function." Homology = Origin.

Final Logic: Anatomical origin (axillary bud) is the decisive evidence for homology.

🧠 Memory Trick

"Same Start Position = Shared Origin = Homology."

📚 Evolution – Topic: Thorns and Tendrils

10 Sweet potato and potato modifications are considered analogous. If a geneticist compared the specific genes regulating the formation of the starch-storing tissues in both organs, what would they most likely find according to evolutionary theory?

A The exact same genetic sequences inherited from a recent shared tuberous ancestor.

B Entirely different genetic pathways that have independently achieved the same physiological outcome.

C A completely homologous biochemical pathway matching the structural homology.

D That the sweet potato genes mutated directly from the potato genes within a single generation.

💡 Short Explanation

Analogy = Independent evolution. Convergent evolution implies separate ancestral origins. Therefore, the genes controlling them are likely unrelated.

✅ Correct Answer Explanation

�� Convergent evolution means the trait evolved separately. Nature found two different "solutions" (root vs. stem modification) to the same "problem" (starch storage). Therefore, the underlying genetic "programs" are expected to be distinct because they didn't evolve from a common starch-storage blueprint.

❓ Why Other Options Are Incorrect

Option A → They do not share a common tuberous ancestor.
Option C → They are analogous, not homologous.
Option D → Evolution takes thousands of years; one-generation mutation is not applicable here.

🎯 Strategy

Used: Substitution

Application: Replace "Convergent Evolution" with "Independent Solutions." Independent solutions require independent paths.

Final Logic: Independence in evolutionary history necessitates independence in genetic regulation.

🧠 Memory Trick

"Convergent = Different Roots (Independent) = Different Genetic Pathways."

📚 Evolution – Topic: Root and Stem Modifications

11 Based on von Baer's refutation, which of the following is NOT an analytically sound conclusion regarding the vestigial gill slits in human embryos?

A They demonstrate that human development mirrors some shared ancestral vertebrate traits.

B They prove that a human embryo temporarily exists as an adult fish during gestation.

C They are a functional organ in adult fish but non-functional in adult humans.

D Their presence does not mean the embryo passes through the adult stage of lower animals.

💡 Short Explanation

Embryos show ancestral traits (pharyngeal arches). Embryos do NOT become adult fish. This is the exact misconception von Baer corrected.

✅ Correct Answer Explanation

�� This statement is the hallmark of the "Recapitulation Theory" which von Baer successfully refuted. Humans develop pharyngeal arches (vestigial gill-like slits) as part of their embryonic development program, but at no point does a human embryo resemble an adult fish. It remains a human embryo throughout.

❓ Why Other Options Are Incorrect

Option A → Shared traits are evidence of common ancestry.
Option C → Correct: Fish have gills; humans do not (as adults).
Option D → Correct: This is the very conclusion of von Baer's refutation.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Identify the option that echoes the "Recapitulation Theory" which the question asks to be "NOT sound."

Final Logic: B is the scientifically incorrect conclusion refuted by von Baer.

🧠 Memory Trick

"Not Fish = Not Recapitulation."

📚 Evolution – Topic: Baer's Law Refutation

12 Karl Ernst von Baer's careful study structurally dismantled Heckel's theory. What evolutionary reality does Baer's observation support instead?

A Embryos of related organisms share developmental blueprints (common ancestry), but diverge before reaching adult morphology.

B Evolution occurs strictly through spontaneous generation of completely distinct embryos.

C Adult forms dictate the embryological stages of completely unrelated organisms.

D There is no biochemical or structural link between different vertebrate classes.

💡 Short Explanation

Development is conservative. Early stages are similar (shared blueprint). Later stages diverge (specialization).

✅ Correct Answer Explanation

�� Von Baer recognized that embryos are more similar than adults. He proposed that development proceeds from general characteristics to specific ones. This supports the concept of common ancestry—that related species begin their life cycles with a shared program, only differentiating as they prepare to take on their specialized adult roles.

❓ Why Other Options Are Incorrect

Option B → Spontaneous generation is false.
Option C → Adult forms do not "dictate" the embryo.
Option D → There is strong structural/biochemical evidence linking vertebrate classes.

🎯 Strategy

Used: Substitution

Application: Replace "Baer's Observation" with "Developmental Divergence."

Final Logic: A represents the modern understanding of development as a divergence from shared early forms.

🧠 Memory Trick

"Early embryo = Similar; Adult = Divergent."

📚 Evolution – Topic: Baer's Law Refutation

13 Match the analytical conclusion to its primary category of evolutionary evidence:

Column I	Column II
I. The presence of identical cytochrome c protein patterns across taxa	P. Anatomical Analogy
II. The structural map of humerus, radius, and ulna in tetrapods	Q. Paleontological Evidence
III. The functional similarity of sweet potato and potato	R. Biochemical Evidence
IV. The timeline of extinction events in distinct rock layers	S. Morphological Homology

A I-R, II-S, III-P, IV-Q

B I-R, II-P, III-S, IV-Q

C I-S, II-R, III-P, IV-Q

D I-Q, II-S, III-P, IV-R

💡 Short Explanation

Cytochrome c = Biochemistry (R). Limb bones = Homology (S). Sweet potato/potato = Analogy (P). Extinction timeline = Paleontology (Q).

✅ Correct Answer Explanation

�� Cytochrome c is a standard protein analyzed for biochemical evidence (R). Bone maps illustrate morphological homology (S). Sweet potato/potato are analogous (P). Rock layers are paleontological (Q). This matches perfectly with A.

❓ Why Other Options Are Incorrect

Option B, C, D → All misidentify the evolutionary category for at least one item.

🎯 Strategy

Used: Option Grouping

Application: Match I-R (Biochemistry) and II-S (Homology) first. Only A begins with I-R, II-S.

Final Logic: A is the only consistent match.

🧠 Memory Trick

"I=Bio(R), II=Homo(S), III=Analog(P), IV=Paleo(Q)."

📚 Evolution – Topic: Biochemical Evidence

14 Why does the presence of shared gene sequences performing a given function among diverse organisms provide stronger confirmation of common ancestry than morphological similarities alone?

A Because genes are immune to the forces of natural selection and mutation.

B Because biochemical molecules are the fundamental inherited blueprints; if vastly different organisms share them, the statistical probability of independent convergent evolution at the sequence level is extremely low.

C Because shared gene sequences only occur in organisms that live in identical habitats.

D Because morphology is purely subjective and cannot be measured scientifically.

💡 Short Explanation

Genes are the blueprint. Sequence similarity is too complex to be "chance." High complexity = Strong proof of shared descent.

✅ Correct Answer Explanation

�� Convergent evolution can create similar shapes (morphology), but the "code" for these traits can be very different. If two different organisms use the exact same DNA sequence to build a specific protein, it is statistically impossible that this happened by accident. It is proof of a common original blueprint.

❓ Why Other Options Are Incorrect

Option A → Genes are definitely subject to mutation and selection.
Option C → Shared genes are found across all life, regardless of habitat.
Option D → Morphology is objective and measurable.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Choose the option that emphasizes statistical proof (common ancestry).

Final Logic: The complexity of genetic information makes independent convergence extremely unlikely at the sequence level.

🧠 Memory Trick

"DNA = Specific Blueprint = Proof of Ancestry."

📚 Evolution – Topic: Shared Gene Sequences

15 In arguing that nature could create new species over millions of years if man could create new breeds in centuries, what underlying assumption about the mechanism of selection is being made?

A Man creates genetic variation from scratch, whereas nature only utilizes existing traits.

B Both artificial and natural selection rely on the differential reproductive success of heritable variations, just operating on vastly different time scales.

C Anthropogenic evolution is entirely random, while natural selection is guided by a predetermined goal.

D Breeding requires identical environments, whereas natural selection requires fluctuating environments.

💡 Short Explanation

Artificial Selection (man) = Selective breeding. Natural Selection = Environmental success. Both rely on heritable variation being selected for survival/reproduction.

✅ Correct Answer Explanation

�� The core argument is about the mechanism. Both man and nature act as "filters" that select specific, heritable traits that lead to successful reproduction. The difference lies only in the time allowed and the nature of the selection pressure.

❓ Why Other Options Are Incorrect

Option A → Man doesn't create traits "from scratch" (he breeds existing ones).
Option C → Natural selection is not goal-oriented (deterministic).
Option D → Both can happen in various environmental conditions.

🎯 Strategy

Used: Substitution

Application: Replace "Anthropogenic Evolution" with "Artificial Selection." It's just a faster version of natural selection.

Final Logic: The similarity in the fundamental mechanism is the basis of the comparison.

🧠 Memory Trick

"Artificial vs. Natural = Same Mechanism, Different Time."

📚 Evolution – Topic: Anthropogenic Evolution

16 Analyze the following statements concerning domesticated animal variation:
I. Intensive breeding programs selectively concentrate specific phenotypic variations within isolated populations.
II. The resulting breeds are distinct but remain part of the same biological group or species.
III. Domesticated breeds have evolved completely independent genetic codes.
IV. The variation observed validates the potential power of selection over time. Which statements are analytically correct?

A I, II, and IV only

B II and III only

C I, III, and IV only

D I, II, III, and IV

💡 Short Explanation

Selective breeding = Phenotype concentration. Breeds = Same species (sub-groups). Genetics = Closely linked (not independent). Power of selection = Validated.

✅ Correct Answer Explanation

�� Statement I describes how selective breeding works (concentrating traits). Statement II is correct: all dog breeds are Canis lupus familiaris. Statement IV is the core takeaway of artificial selection. Statement III is false: they share the same overarching genetic architecture.

❓ Why Other Options Are Incorrect

Option B, C, D → Include statement III, which is false.

🎯 Strategy

Used: Elimination

Application: Eliminate III. Since the breeds are all part of the same species, they cannot have "completely independent" genetic codes.

Final Logic: A is the only valid set containing correct logical deductions.

🧠 Memory Trick

"Breeds = Subgroups of ONE species."

📚 Evolution – Topic: Domesticated Animal Variation

17 Arrange the complex sequence of population dynamics in the peppered moth case study spanning changing environmental phases:
I. Industrial pollution clears (post-1920s hypothetical or rural areas), lichens return, and melanic moth counts become low.
II. Pre-industrialisation: Thick white lichen covers trees; white-winged moths outcompete dark-winged moths in avoiding predation.
III. Industrialisation occurs: Smoke and soot kill lichens and darken tree trunks.
IV. Dark-winged moths possess a survival advantage via camouflage, increasing their relative proportion in the population.

A II, III, IV, I

B III, II, IV, I

C II, IV, III, I

D I, II, III, IV

💡 Short Explanation

II = Start (White lichen dominance). III = Change (Industrialization). IV = Result (Camouflage advantage). I = Recovery/Reversion (Lichens return).

✅ Correct Answer Explanation

�� The process flows: Starting state (II) -> Environmental stress (III) -> Selection/Survival (IV) -> Reversion/Recovery (I). This accurately maps the ecological timeline of the Peppered Moth study.

❓ Why Other Options Are Incorrect

Option B, C, D → Misorder the sequence, causing illogical breaks in the evolutionary timeline (e.g., reversing industrialization or recovery).

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Map the stages: Baseline -> Stress -> Selection -> Reversion.

Final Logic: A is the only sequence reflecting ecological succession and response.

🧠 Memory Trick

"White Start -> Soot -> Dark Survival -> Lichen Recovery."

📚 Evolution – Topic: Peppered Moth Case Study

18 Which of the following analytical statements about the camouflage of moths is NOT supported by the evolutionary evidence?

A Camouflage acts as a selective advantage dependent entirely on the prevailing environmental background.

B Predators act as the agent of natural selection by spotting contrasting moths.

C The ability to camouflage resulted in the complete and permanent wiping out of the less-adapted variant from the gene pool.

D The survival rate of a specific wing color is directly tied to the presence or absence of industrial lichens.

💡 Short Explanation

Selection works by frequency, not extinction. Rarely is a variant "wiped out" entirely. Diversity is maintained in populations.

✅ Correct Answer Explanation

�� Natural selection changes proportions, not necessarily causing permanent extinction. The text explicitly notes that neither variant is completely wiped out during the selective shifts of the moth population. Therefore, statement C is the one that is NOT supported.

❓ Why Other Options Are Incorrect

Option A → Correct; selection is background-dependent.
Option B → Correct; predation drives the selection pressure.
Option D → Correct; lichens determine the background (the selection factor).

🎯 Strategy

Used: Extreme Word Filter

Application: Look for the word "complete and permanent wiping out." This is an absolute statement that rarely holds in biological systems.

Final Logic: Evolution shifts frequencies; it does not typically delete alleles entirely.

🧠 Memory Trick

"Selection ≠ Extinction."

📚 Evolution – Topic: Camouflage and Predation

📄 Passage

"Excess use of herbicides, pesticides, etc., has only resulted in selection of resistant varieties in a much lesser time scale. This is also true for microbes against which we employ antibiotics or drugs against eukaryotic organisms/cell. Hence, resistant organisms/cells are appearing in a time scale of months or years and not centuries. These are examples of evolution by anthropogenic action. This also tells us that evolution is not a directed process in the sense of determinism. It is a stochastic process based on chance events in nature and chance mutation in the organisms."

According to the passage, the emergence of antibiotic-resistant microbes fundamentally refutes which philosophical view of evolution?

A That evolution is a stochastic process based on chance.

B That chance mutations play a role in survival.

C That evolution can occur via anthropogenic action.

D That evolution is a directed, deterministic process aiming toward a final "perfect" form.

💡 Short Explanation

Passage explicitly says: "...evolution is not a directed process in the sense of determinism." Determinism = Goal-oriented. Resistance = Random mutation + Selection.

✅ Correct Answer Explanation

�� The passage uses the speed and nature of antibiotic resistance to argue against "determinism." If evolution were directed toward a goal (a "perfect" organism), antibiotic resistance wouldn't need to be so rapid and reactive to human chemicals. Instead, the randomness of mutation dictates survival.

❓ Why Other Options Are Incorrect

Option A → The passage supports evolution being stochastic.
Option B → The passage supports the role of chance mutations.
Option C → The passage supports anthropogenic evolution.

🎯 Strategy

Used: Contextual/Tonal Matching

Application: Search the passage for "determinism" or "directed process" and link it to the refutation.

Final Logic: The passage explicitly states evolution is not deterministic.

🧠 Memory Trick

"Antibiotic resistance = Stochastic (NOT Directed)."

📚 Evolution – Topic: Antibiotic Resistance

📄 Passage

Based on the passage, the rapid time scale (months or years) of herbicide resistance is biologically possible primarily because:

A Herbicides physically induce specific, targeted mutations in the plant's DNA.

B The application of chemicals acts as a severe selective pressure on a population where chance mutant variants already exist.

C Anthropogenic action is deterministic and purposefully guides the plants to evolve.

D Resistant varieties possess a longer lifespan than centuries.

💡 Short Explanation

Selection acts on existing variance. Chemicals are the "filter" (pressure). Chance mutation creates the raw material.

✅ Correct Answer Explanation

�� Antibiotics/Herbicides don't "create" resistance mutations; they kill everything except those that happened (by chance) to already be resistant. Because the selective pressure is so intense, the few resistant variants multiply rapidly, making the change appear in just months.

❓ Why Other Options Are Incorrect

Option A → Herbicides do not "target" mutation creation.
Option C → Anthropogenic action is not "purposefully guiding" evolution (as stated in the passage refuting determinism).
Option D → Lifespan is irrelevant to the evolutionary mechanism.

🎯 Strategy

Used: Substitution

Application: Replace "Selective Pressure" with "Filter." The filter catches what exists; it doesn't create the shape of the survivor.

Final Logic: Selection works on pre-existing chance mutations, explaining the speed.

🧠 Memory Trick

"Pressure = Filter (Selects existing variants)."

📚 Evolution – Topic: Herbicide and Pesticide Resistance

CUET UG Biology Booster Test 3 Evidences for Biological Evolution

Test Complete!

Answer Review