BIOD 102 (ESSENTIAL BIOLOGY II WITH LABORATORY)
COMPLETE PRACTICE EXAM | ORIGINAL QUESTIONS &
ANSWERS | COMPREHENSIVE FINAL EXAM REVIEW |
UPDATED 2026/2027
Practice Examination
BIOD 102 – Essential Biology II with Laboratory
2026/2027 Edition
COMPLETE PRACTICE EXAM
100 Original Multiple-Choice Questions
Passing Score: 70%
Testing Time: 120 Minutes
TABLE OF CONTENTS
1. Evolution and Natural Selection
2. Population Genetics
3. Ecology
4. Animal Diversity
5. Plant Structure and Function
6. Human Anatomy and Physiology
7. Reproduction and Development
8. Immunology and Disease
9. Laboratory Methods and Data Analysis
10. Scientific Reasoning and Experimental Design
ACADEMIC BIOLOGY PROGRAM || ALIGNED WITH MODERN UNDERGRADUATE
BIOLOGY CURRICULA || COMPREHENSIVE FINAL EXAM PREPARATION || ORIGINAL
PRACTICE QUESTIONS || VERIFIED FOR EDUCATIONAL USE || PREPARED FOR
,UNIVERSITY BIOLOGY STUDENTS || UPDATED 2026/2027 EDITION || PROFESSIONAL
ACADEMIC STUDY GUIDE
Evolution and Natural Selection (Questions 1–8)
QUESTION 1
A population of insects develops resistance to a pesticide after several generations of
exposure. Which mechanism best explains this evolutionary change?
A. Individuals intentionally adapted to survive.
B. Resistant individuals were more likely to survive and reproduce.
C. All insects acquired identical resistance mutations simultaneously.
D. Exposure directly caused beneficial mutations in every individual.
Correct Answer: B. Resistant individuals were more likely to survive and reproduce.
Explanation: Natural selection acts on existing heritable variation. Individuals
possessing resistance genes survive pesticide exposure and leave more offspring,
increasing the frequency of resistance alleles over generations. Option A incorrectly
suggests purposeful adaptation. Option C ignores genetic variation, while Option D
incorrectly assumes mutations occur because organisms "need" them.
QUESTION 2
A researcher compares homologous structures among mammals to reconstruct
evolutionary relationships. Which conclusion is most strongly supported?
A. Homologous structures indicate common ancestry.
B. Homologous structures always perform identical functions.
C. Homologous structures evolve only through convergent evolution.
D. Homologous structures prove species cannot continue evolving.
,Correct Answer: A. Homologous structures indicate common ancestry.
Explanation: Homologous structures share a common evolutionary origin even if their
present-day functions differ. Functional similarity is not required. Convergent evolution
produces analogous—not homologous—structures. Evolution remains an ongoing
process.
QUESTION 3
Which population is most likely to evolve rapidly following a dramatic environmental
change?
A. A genetically diverse population
B. A completely uniform population
C. A population reproducing only asexually with no mutations
D. A population with identical genomes
Correct Answer: A. A genetically diverse population.
Explanation: Greater genetic diversity provides more variation on which natural
selection can act. Uniform populations have fewer adaptive possibilities and are
therefore more vulnerable to environmental change.
QUESTION 4
A mutation arises in a somatic cell of an adult frog. What is its greatest evolutionary
significance?
A. It immediately spreads through the species.
B. It affects future generations directly.
C. It generally has no effect on evolution because it is not inherited.
D. It guarantees speciation.
, Correct Answer: C. It generally has no effect on evolution because it is not
inherited.
Explanation: Somatic mutations affect only body cells and are not transmitted through
gametes. Only heritable mutations contribute directly to evolutionary change.
QUESTION 5
Which situation best illustrates directional selection?
A. Birds with intermediate beak sizes are favored.
B. Birds with very small and very large beaks are favored equally.
C. Larger beaks become increasingly common because only large seeds remain.
D. Every beak size survives equally well.
Correct Answer: C. Larger beaks become increasingly common because only large
seeds remain.
Explanation: Directional selection favors one extreme phenotype, shifting the
population toward that trait. Stabilizing selection favors intermediate forms, while
disruptive selection favors both extremes.
QUESTION 6
A biologist discovers that two isolated populations can no longer produce fertile
offspring when crossed. This finding indicates:
A. Genetic drift has stopped.
B. Reproductive isolation has occurred.
C. Natural selection has ended.
D. Mutation rates have become zero.
COMPLETE PRACTICE EXAM | ORIGINAL QUESTIONS &
ANSWERS | COMPREHENSIVE FINAL EXAM REVIEW |
UPDATED 2026/2027
Practice Examination
BIOD 102 – Essential Biology II with Laboratory
2026/2027 Edition
COMPLETE PRACTICE EXAM
100 Original Multiple-Choice Questions
Passing Score: 70%
Testing Time: 120 Minutes
TABLE OF CONTENTS
1. Evolution and Natural Selection
2. Population Genetics
3. Ecology
4. Animal Diversity
5. Plant Structure and Function
6. Human Anatomy and Physiology
7. Reproduction and Development
8. Immunology and Disease
9. Laboratory Methods and Data Analysis
10. Scientific Reasoning and Experimental Design
ACADEMIC BIOLOGY PROGRAM || ALIGNED WITH MODERN UNDERGRADUATE
BIOLOGY CURRICULA || COMPREHENSIVE FINAL EXAM PREPARATION || ORIGINAL
PRACTICE QUESTIONS || VERIFIED FOR EDUCATIONAL USE || PREPARED FOR
,UNIVERSITY BIOLOGY STUDENTS || UPDATED 2026/2027 EDITION || PROFESSIONAL
ACADEMIC STUDY GUIDE
Evolution and Natural Selection (Questions 1–8)
QUESTION 1
A population of insects develops resistance to a pesticide after several generations of
exposure. Which mechanism best explains this evolutionary change?
A. Individuals intentionally adapted to survive.
B. Resistant individuals were more likely to survive and reproduce.
C. All insects acquired identical resistance mutations simultaneously.
D. Exposure directly caused beneficial mutations in every individual.
Correct Answer: B. Resistant individuals were more likely to survive and reproduce.
Explanation: Natural selection acts on existing heritable variation. Individuals
possessing resistance genes survive pesticide exposure and leave more offspring,
increasing the frequency of resistance alleles over generations. Option A incorrectly
suggests purposeful adaptation. Option C ignores genetic variation, while Option D
incorrectly assumes mutations occur because organisms "need" them.
QUESTION 2
A researcher compares homologous structures among mammals to reconstruct
evolutionary relationships. Which conclusion is most strongly supported?
A. Homologous structures indicate common ancestry.
B. Homologous structures always perform identical functions.
C. Homologous structures evolve only through convergent evolution.
D. Homologous structures prove species cannot continue evolving.
,Correct Answer: A. Homologous structures indicate common ancestry.
Explanation: Homologous structures share a common evolutionary origin even if their
present-day functions differ. Functional similarity is not required. Convergent evolution
produces analogous—not homologous—structures. Evolution remains an ongoing
process.
QUESTION 3
Which population is most likely to evolve rapidly following a dramatic environmental
change?
A. A genetically diverse population
B. A completely uniform population
C. A population reproducing only asexually with no mutations
D. A population with identical genomes
Correct Answer: A. A genetically diverse population.
Explanation: Greater genetic diversity provides more variation on which natural
selection can act. Uniform populations have fewer adaptive possibilities and are
therefore more vulnerable to environmental change.
QUESTION 4
A mutation arises in a somatic cell of an adult frog. What is its greatest evolutionary
significance?
A. It immediately spreads through the species.
B. It affects future generations directly.
C. It generally has no effect on evolution because it is not inherited.
D. It guarantees speciation.
, Correct Answer: C. It generally has no effect on evolution because it is not
inherited.
Explanation: Somatic mutations affect only body cells and are not transmitted through
gametes. Only heritable mutations contribute directly to evolutionary change.
QUESTION 5
Which situation best illustrates directional selection?
A. Birds with intermediate beak sizes are favored.
B. Birds with very small and very large beaks are favored equally.
C. Larger beaks become increasingly common because only large seeds remain.
D. Every beak size survives equally well.
Correct Answer: C. Larger beaks become increasingly common because only large
seeds remain.
Explanation: Directional selection favors one extreme phenotype, shifting the
population toward that trait. Stabilizing selection favors intermediate forms, while
disruptive selection favors both extremes.
QUESTION 6
A biologist discovers that two isolated populations can no longer produce fertile
offspring when crossed. This finding indicates:
A. Genetic drift has stopped.
B. Reproductive isolation has occurred.
C. Natural selection has ended.
D. Mutation rates have become zero.
