ESTUDYR
PCB4674 EXAM 1, EXAM 2 & FINAL EXAMS (LATEST
2026/ 2027 UPDATES STUDY BUNDLE PACKAGE WITH
SOLUTIONS
1. Which statement about whale evolution is true?
A. Once all missing links are found, whale evolution will be fully understood.
B. DNA evidence allows scientists to understand most of the early history of whale evolution.
C. The fossil record demonstrates that the transition from land to sea happened all at once.
D. D. The fossil record provides evidence about the timing of certain events in whale evolution.
✔
Rationale: Fossils give temporal context and transitional morphologies, though they don't
answer every question.
2. Influenza viruses evolve rapidly and evade immune detection mainly by:
A. Gradual changes in host behavior.
B. Point mutations only.
C. Loss of antigenic proteins.
D. D. Reassorting genes of multiple viral strains during replication (genetic reassortment). ✔
Rationale: Reassortment of segmented genomes (e.g., influenza) generates novel antigenic
combinations.
3. Which of the following data sources can be used to study evolution?
A. Trait frequencies in contemporary populations only.
B. Morphological data from fossils only.
C. DNA sequence data only.
D. D. All of the above (trait frequencies, fossil morphology, DNA sequences). ✔
Rationale: Evolutionary inference uses multiple data types—phenotypes, fossils, and
sequences—for robust conclusions.
4. Which intellectual predecessor had the least influence on Darwin’s development of natural
selection?
A. Thomas Malthus
B. Georges Cuvier
C. Charles Lyell
D. D. Gregor Mendel’s work on pea genetics (Mendel’s work was not widely known to
Darwin). ✔
Rationale: Mendel’s genetics was published before its significance was recognized, so it didn’t
shape Darwin’s ideas.
5. Thomas Malthus’ mathematical description of human population dynamics helped explain:
A. The origin of species by mutation.
, ESTUDYR
B. Geological strata formation.
C. C. Why organisms face a “struggle for existence” (competition for limited resources). ✔
Rationale: Malthus highlighted exponential growth vs. finite resources, a key idea influencing
natural selection.
6. Lord Kelvin argued Earth was too young for evolution based on rock temperatures. What was
wrong?
A. He overestimated radioactive heating.
B. B. He didn’t know Earth’s interior was heated by radioactive decay (not yet discovered). ✔
C. He ignored fossil evidence.
D. He used wrong chemical composition for rocks.
Rationale: Kelvin lacked knowledge of radioactive heat sources, underestimating Earth’s age.
7. The decline of grasses over the last ~20 million years has been explained by:
A. A sudden drop in oxygen concentration.
B. Continental drift only.
C. C. A decline in atmospheric CO₂ concentration affecting grass physiology. ✔
D. Massive viral epidemics of grasses.
Rationale: Lower CO₂ can change plant competitive dynamics favoring some lineages over
grasses.
8. The transition from single-celled to multicellular eukaryotes:
A. Happened once in a single lineage only.
B. Occurred after the origin of modern animals only.
C. C. Occurred repeatedly in different groups and preceded some eukaryotic diversification
events. ✔
D. Is limited to plants.
Rationale: Multicellularity evolved multiple times independently across eukaryotes.
9. Modern mammals are most recently descended from which group?
A. Reptiles (in the colloquial sense) unrelated to synapsids.
B. Deuterostomes.
C. C. Synapsids (the lineage that gave rise to mammals). ✔
D. Amphibians directly.
Rationale: Mammals evolved from synapsid ancestors (therapsids) in the amniote tree.
10. Tetrapods include:
A. Organisms descended from ancestors with four limbs.
B. Birds.
C. Whales.
D. D. All of the above. ✔
PCB4674 EXAM 1, EXAM 2 & FINAL EXAMS (LATEST
2026/ 2027 UPDATES STUDY BUNDLE PACKAGE WITH
SOLUTIONS
1. Which statement about whale evolution is true?
A. Once all missing links are found, whale evolution will be fully understood.
B. DNA evidence allows scientists to understand most of the early history of whale evolution.
C. The fossil record demonstrates that the transition from land to sea happened all at once.
D. D. The fossil record provides evidence about the timing of certain events in whale evolution.
✔
Rationale: Fossils give temporal context and transitional morphologies, though they don't
answer every question.
2. Influenza viruses evolve rapidly and evade immune detection mainly by:
A. Gradual changes in host behavior.
B. Point mutations only.
C. Loss of antigenic proteins.
D. D. Reassorting genes of multiple viral strains during replication (genetic reassortment). ✔
Rationale: Reassortment of segmented genomes (e.g., influenza) generates novel antigenic
combinations.
3. Which of the following data sources can be used to study evolution?
A. Trait frequencies in contemporary populations only.
B. Morphological data from fossils only.
C. DNA sequence data only.
D. D. All of the above (trait frequencies, fossil morphology, DNA sequences). ✔
Rationale: Evolutionary inference uses multiple data types—phenotypes, fossils, and
sequences—for robust conclusions.
4. Which intellectual predecessor had the least influence on Darwin’s development of natural
selection?
A. Thomas Malthus
B. Georges Cuvier
C. Charles Lyell
D. D. Gregor Mendel’s work on pea genetics (Mendel’s work was not widely known to
Darwin). ✔
Rationale: Mendel’s genetics was published before its significance was recognized, so it didn’t
shape Darwin’s ideas.
5. Thomas Malthus’ mathematical description of human population dynamics helped explain:
A. The origin of species by mutation.
, ESTUDYR
B. Geological strata formation.
C. C. Why organisms face a “struggle for existence” (competition for limited resources). ✔
Rationale: Malthus highlighted exponential growth vs. finite resources, a key idea influencing
natural selection.
6. Lord Kelvin argued Earth was too young for evolution based on rock temperatures. What was
wrong?
A. He overestimated radioactive heating.
B. B. He didn’t know Earth’s interior was heated by radioactive decay (not yet discovered). ✔
C. He ignored fossil evidence.
D. He used wrong chemical composition for rocks.
Rationale: Kelvin lacked knowledge of radioactive heat sources, underestimating Earth’s age.
7. The decline of grasses over the last ~20 million years has been explained by:
A. A sudden drop in oxygen concentration.
B. Continental drift only.
C. C. A decline in atmospheric CO₂ concentration affecting grass physiology. ✔
D. Massive viral epidemics of grasses.
Rationale: Lower CO₂ can change plant competitive dynamics favoring some lineages over
grasses.
8. The transition from single-celled to multicellular eukaryotes:
A. Happened once in a single lineage only.
B. Occurred after the origin of modern animals only.
C. C. Occurred repeatedly in different groups and preceded some eukaryotic diversification
events. ✔
D. Is limited to plants.
Rationale: Multicellularity evolved multiple times independently across eukaryotes.
9. Modern mammals are most recently descended from which group?
A. Reptiles (in the colloquial sense) unrelated to synapsids.
B. Deuterostomes.
C. C. Synapsids (the lineage that gave rise to mammals). ✔
D. Amphibians directly.
Rationale: Mammals evolved from synapsid ancestors (therapsids) in the amniote tree.
10. Tetrapods include:
A. Organisms descended from ancestors with four limbs.
B. Birds.
C. Whales.
D. D. All of the above. ✔
