Human Evolution - Competency-Based Question Bank (with Answers)

Section A: Case-Based Questions

Case Study 1: Fossil skull with small brain and prominent brow ridge (Homo erectus).

What does "Homo erectus" mean?
- Answer: "Upright man" (referring to fully bipedal gait).
Cranial capacity comparison.
- Answer: Homo erectus: 800-1100 cc. Modern man (Homo sapiens): Approx 1450 cc.
Designing: Timeline.
- Answer: Homo habilis -> Homo erectus -> Homo neanderthalensis -> Homo sapiens.
Analysis: Significance of bipedalism.
- Answer: Freed the hands for tool use/carrying, allowed for a higher line of sight, and was more energy-efficient for long-distance travel.
Did they use tools?
- Answer: Yes, they made sophisticated stone tools like hand axes (Acheulean tools) and were the first to use fire.

Case Study 2: Lamarck vs Darwin on giraffe's neck. 6. Lamarck's view.

Answer: "Acquired Character". He believed the neck stretched during the organism's life and this change was passed to offspring.

Darwin's view.
- Answer: Natural Selection. Giraffes with naturally longer necks survived drought better (as they could reach leaves) and reproduced more.
Creating: Comic strip.
- Answer: [Darwin: "Only the long-necked ones survived." Lamarck: "They just kept stretching until they grew."]
Critical Thinking: Why Lamarck rejected?
- Answer: Experiments showed that changes in somatic cells (like cutting tails of mice) are not inherited; only changes in germ cells (DNA) are.
Example of non-inherited trait.
- Answer: Pierced ears, scars, or knowledge/skills learned during a lifetime.

Section B: Assertion-Reasoning Questions

Directions: (a) Both A/R true, R explains A; (b) Both true, R doesn't explain A; (c) A true, R false; (d) A false, R true.

Assertion (A): Appendix is vestigial. Reason (R): Functional in ancestors for cellulose digestion.
- Answer: (a) Both A and R are true and R is the correct explanation.
Assertion (A): Australopithecus is a connecting link. Reason (R): Character of both apes and humans.
- Answer: (a) Both A and R are true and R is the correct explanation.
Assertion (A): Homologous organs show divergent evolution. Reason (R): Same structural origin, different functions.
- Answer: (a) Both A and R are true and R is the correct explanation.
Assertion (A): Neanderthals were first to bury dead. Reason (R): Sense of culture.
- Answer: (a) Both A and R are true and R is the correct explanation.
Assertion (A): Industrial Melanism is Natural Selection. Reason (R): Dark moths survived better in soot.
- Answer: (a) Both A and R are true and R is the correct explanation.

Section C: Creating and Designing (Application & Analysis)

Designing: Cladogram.
- Answer: [Fish -> Amphibian -> Reptile -> (Bird/Mammal)].
Creating: Archaeopteryx poster.
- Answer: "Missing Link found. Has teeth and tail like a reptile, but feathers and wings like a bird."
Analysis: Homologous vs Analogous.
- Answer: Homologous: Same origin, different function (Common ancestor). Analogous: Different origin, same function (Environment/Convergent evolution).
Designing: H. habilis vs H. sapiens table.
- Answer: [H. habilis: 650-800cc, "Handy man", first tool maker. H. sapiens: 1450cc, complex culture, agriculture].
Visualisation: Forelimbs.
- Answer: [Sketch showing pentadactyl limb pattern across bat, whale, and human].
Application: "Goosebumps".
- Answer: Arrector pili muscles contract to fluff up fur (trapping heat or looking bigger); since we lost our fur, the response is vestigial.
Creating: Neanderthal story.
- Answer: [Focus on group hunting, use of fire for warmth, and caring for the injured].
Analysis: Opposable Thumb.
- Answer: Allowed for a "precision grip," enabling humans to make and use fine tools and eventually write.
Designing: CC Quiz.
- Answer: [650-800: H. habilis. 900: H. erectus. 1450: H. sapiens].
Creating: Survival of Fittest for kids.
- Answer: "Nature chooses the animals that have the best 'superpowers' for where they live."

Section D: Competency & Critical Thinking

Speciation.
- Answer: Formation of new species. Isolation prevents interbreeding; separate mutations and selection lead to different traits until they can no longer mate.
Scenario: Antibiotic resistance.
- Answer: Some bacteria have a natural mutation for resistance. When antibiotics are used, only these "fit" ones survive and reproduce, creating a resistant population.
Critical Thinking: Are humans still evolving?
- Answer: Yes (e.g., lactose tolerance, wisdom teeth disappearing), but cultural/medical evolution is now faster than biological evolution.
Application: Carbon Dating.
- Answer: Measures the decay of Carbon-14 in organic fossils to determine their age (up to 50,000 years).
Ontogeny vs Phylogeny.
- Answer: Ontogeny: Development of an individual embryo. Phylogeny: Evolutionary history of a species.
Diagram Based: Galapagos Finches.
- Answer: Different beaks evolved from a common ancestor to exploit different food sources (seeds, insects, nectar) on different islands.
Role of Mutation.
- Answer: It is the primary source of new genetic variations upon which natural selection acts.
Analysis: Cro-Magnon.
- Answer: They were identical to modern humans in anatomy, had advanced art (cave paintings), and used complex bone/stone tools.
Competency: "Living Fossils".
- Answer: Species that have remained largely unchanged for millions of years (e.g., King Crab).
Case: Mountain isolation.
- Answer: Geographical isolation leads to reproductive isolation over time.
Creating: Dinosaur extinction hypothesis.
- Answer: True; the mass extinction of dinosaurs cleared ecological niches, allowing small mammals to diversify and grow.
Designing: Vestigial visual aid.
- Answer: [Sketch pointing to tailbone (Coccyx), wisdom teeth, and nictitating membrane (eye corner)].
Application: Embryology evidence.
- Answer: Early embryos of fish, birds, and humans look almost identical, suggesting a common vertebrate ancestor.
Critical Thinking: "Out of Africa" theory.
- Answer: Suggests all modern humans originated in Africa and migrated to other continents. Supported by DNA evidence.
Analysis: Gene Pool.
- Answer: The total set of unique alleles in a population.

Section E: Advanced Competency

Scenario: Artificial vs Natural Selection.
- Answer: Artificial: Humans choose traits (fast). Natural: Environment chooses traits (slow).
Designing: Camouflage model.
- Answer: Use green and brown colored buttons on a green lawn; birds (students) will pick up more brown ones.
Application: Embryo gill slits.
- Answer: Remnants of our aquatic ancestry; in humans, they develop into parts of the ear and throat.
Creating: Timeline.
- Answer: [Cenozoic Era: Age of Mammals and Humans].
Case Study: Sickle Cell Heterozygote advantage.
- Answer: People with one sickle-cell gene (carriers) are resistant to Malaria, so the gene stays in the population where malaria is common.
Genetic Drift.
- Answer: Random changes in gene frequency in small populations (by chance, not selection).
Critical Thinking: Man from monkeys?
- Answer: No, both evolved from a common ancestor that was neither a modern monkey nor a modern man.
Analysis: Ape vs Human jaw.
- Answer: Ape: U-shaped, protruding (Prognathous). Human: Semi-circular, flatter (Orthognathous).
Designing: Brain size chart.
- Answer: [Australopithecus (450) -> H. habilis (700) -> H. erectus (900) -> H. sapiens (1450)].
Creating: Future Human.
- Answer: [E.g., Larger head, smaller jaw, longer fingers for typing, weaker muscles].

Section A: Case-Based Questions

Case Study 1: Fossil skull with small brain and prominent brow ridge (Homo erectus).

What does "Homo erectus" mean?

Answer: "Upright man" (referring to fully bipedal gait).

Cranial capacity comparison.

Answer: Homo erectus: 800-1100 cc. Modern man (Homo sapiens): Approx 1450 cc.

Designing: Timeline.

Answer: Homo habilis -> Homo erectus -> Homo neanderthalensis -> Homo sapiens.

Analysis: Significance of bipedalism.

Answer: Freed the hands for tool use/carrying, allowed for a higher line of sight, and was more energy-efficient for long-distance travel.

Did they use tools?

Answer: Yes, they made sophisticated stone tools like hand axes (Acheulean tools) and were the first to use fire.

Case Study 2: Lamarck vs Darwin on giraffe's neck. 6. Lamarck's view.

Answer: "Acquired Character". He believed the neck stretched during the organism's life and this change was passed to offspring.

Darwin's view.

Answer: Natural Selection. Giraffes with naturally longer necks survived drought better (as they could reach leaves) and reproduced more.

Creating: Comic strip.

Answer: [Darwin: "Only the long-necked ones survived." Lamarck: "They just kept stretching until they grew."]

Critical Thinking: Why Lamarck rejected?

Answer: Experiments showed that changes in somatic cells (like cutting tails of mice) are not inherited; only changes in germ cells (DNA) are.

Example of non-inherited trait.

Answer: Pierced ears, scars, or knowledge/skills learned during a lifetime.

Section B: Assertion-Reasoning Questions

Directions: (a) Both A/R true, R explains A; (b) Both true, R doesn't explain A; (c) A true, R false; (d) A false, R true.

Assertion (A): Appendix is vestigial. Reason (R): Functional in ancestors for cellulose digestion.

Answer: (a) Both A and R are true and R is the correct explanation.

Assertion (A): Australopithecus is a connecting link. Reason (R): Character of both apes and humans.

Answer: (a) Both A and R are true and R is the correct explanation.

Assertion (A): Homologous organs show divergent evolution. Reason (R): Same structural origin, different functions.

Answer: (a) Both A and R are true and R is the correct explanation.

Assertion (A): Neanderthals were first to bury dead. Reason (R): Sense of culture.

Answer: (a) Both A and R are true and R is the correct explanation.

Assertion (A): Industrial Melanism is Natural Selection. Reason (R): Dark moths survived better in soot.

Answer: (a) Both A and R are true and R is the correct explanation.

Section C: Creating and Designing (Application & Analysis)

Designing: Cladogram.

Answer: [Fish -> Amphibian -> Reptile -> (Bird/Mammal)].

Creating: Archaeopteryx poster.

Answer: "Missing Link found. Has teeth and tail like a reptile, but feathers and wings like a bird."

Analysis: Homologous vs Analogous.

Answer: Homologous: Same origin, different function (Common ancestor). Analogous: Different origin, same function (Environment/Convergent evolution).

Designing: H. habilis vs H. sapiens table.

Answer: [H. habilis: 650-800cc, "Handy man", first tool maker. H. sapiens: 1450cc, complex culture, agriculture].

Visualisation: Forelimbs.

Answer: [Sketch showing pentadactyl limb pattern across bat, whale, and human].

Application: "Goosebumps".

Answer: Arrector pili muscles contract to fluff up fur (trapping heat or looking bigger); since we lost our fur, the response is vestigial.

Creating: Neanderthal story.

Answer: [Focus on group hunting, use of fire for warmth, and caring for the injured].

Analysis: Opposable Thumb.

Answer: Allowed for a "precision grip," enabling humans to make and use fine tools and eventually write.

Designing: CC Quiz.

Answer: [650-800: H. habilis. 900: H. erectus. 1450: H. sapiens].

Creating: Survival of Fittest for kids.

Answer: "Nature chooses the animals that have the best 'superpowers' for where they live."

Section D: Competency & Critical Thinking

Speciation.

Answer: Formation of new species. Isolation prevents interbreeding; separate mutations and selection lead to different traits until they can no longer mate.

Scenario: Antibiotic resistance.

Answer: Some bacteria have a natural mutation for resistance. When antibiotics are used, only these "fit" ones survive and reproduce, creating a resistant population.

Critical Thinking: Are humans still evolving?

Answer: Yes (e.g., lactose tolerance, wisdom teeth disappearing), but cultural/medical evolution is now faster than biological evolution.

Application: Carbon Dating.

Answer: Measures the decay of Carbon-14 in organic fossils to determine their age (up to 50,000 years).

Ontogeny vs Phylogeny.

Answer: Ontogeny: Development of an individual embryo. Phylogeny: Evolutionary history of a species.

Diagram Based: Galapagos Finches.

Answer: Different beaks evolved from a common ancestor to exploit different food sources (seeds, insects, nectar) on different islands.

Role of Mutation.

Answer: It is the primary source of new genetic variations upon which natural selection acts.

Analysis: Cro-Magnon.

Answer: They were identical to modern humans in anatomy, had advanced art (cave paintings), and used complex bone/stone tools.

Competency: "Living Fossils".

Answer: Species that have remained largely unchanged for millions of years (e.g., King Crab).

Case: Mountain isolation.

Answer: Geographical isolation leads to reproductive isolation over time.

Creating: Dinosaur extinction hypothesis.

Answer: True; the mass extinction of dinosaurs cleared ecological niches, allowing small mammals to diversify and grow.

Designing: Vestigial visual aid.

Answer: [Sketch pointing to tailbone (Coccyx), wisdom teeth, and nictitating membrane (eye corner)].

Application: Embryology evidence.

Answer: Early embryos of fish, birds, and humans look almost identical, suggesting a common vertebrate ancestor.

Critical Thinking: "Out of Africa" theory.

Answer: Suggests all modern humans originated in Africa and migrated to other continents. Supported by DNA evidence.

Analysis: Gene Pool.

Answer: The total set of unique alleles in a population.

Section E: Advanced Competency

Scenario: Artificial vs Natural Selection.

Answer: Artificial: Humans choose traits (fast). Natural: Environment chooses traits (slow).

Designing: Camouflage model.

Answer: Use green and brown colored buttons on a green lawn; birds (students) will pick up more brown ones.

Application: Embryo gill slits.

Answer: Remnants of our aquatic ancestry; in humans, they develop into parts of the ear and throat.

Creating: Timeline.

Answer: [Cenozoic Era: Age of Mammals and Humans].

Case Study: Sickle Cell Heterozygote advantage.

Answer: People with one sickle-cell gene (carriers) are resistant to Malaria, so the gene stays in the population where malaria is common.

Genetic Drift.

Answer: Random changes in gene frequency in small populations (by chance, not selection).

Critical Thinking: Man from monkeys?

Answer: No, both evolved from a common ancestor that was neither a modern monkey nor a modern man.

Analysis: Ape vs Human jaw.

Answer: Ape: U-shaped, protruding (Prognathous). Human: Semi-circular, flatter (Orthognathous).

Designing: Brain size chart.

Answer: [Australopithecus (450) -> H. habilis (700) -> H. erectus (900) -> H. sapiens (1450)].

Creating: Future Human.

Answer: [E.g., Larger head, smaller jaw, longer fingers for typing, weaker muscles].

Human Evolution

Human Evolution - Competency-Based Question Bank (with Answers)

Section A: Case-Based Questions

Section B: Assertion-Reasoning Questions

Section C: Creating and Designing (Application & Analysis)

Section D: Competency & Critical Thinking

Section E: Advanced Competency

On this page

BioBot

Human Evolution

Human Evolution - Competency-Based Question Bank (with Answers)

Section A: Case-Based Questions

Section B: Assertion-Reasoning Questions

Section C: Creating and Designing (Application & Analysis)

Section D: Competency & Critical Thinking

Section E: Advanced Competency

On this page