2026 BIOD 101 Module 6 Final Exam – 2026 | Portage Learning | Complete
Verified Q&As + Review Guide
The final comprehensive 100-question series for Module 6. This 2026 update focuses
on Darwinian Fitness, Allopatric Speciation, Trophic Energy Flow, Biogeochemical
Cycles, and Community Interactions. This set is the ultimate preparation tool for the BIOD
101 Final Exam.
1. Which scientist is credited with proposing the theory of Evolution by Natural
Selection?
A. Gregor Mendel
B. Charles Darwin
C. Jean-Baptiste Lamarck
D. Robert Hooke
Rationale: In his work On the Origin of Species, Darwin explained how favorable traits
lead to increased survival and reproduction.
2. "Natural Selection" can only occur if there is _______ within a population.
A. Perfect equality
B. Genetic variation
C. No competition
D. Unlimited food
Rationale: Without variation, there are no different traits for nature to "select" for or
against.
3. Which mechanism of evolution involves a random change in allele frequencies,
typically in small populations?
A. Natural Selection
B. Genetic Drift
C. Gene Flow
D. Mutation
Rationale: Genetic Drift (e.g., the Bottleneck Effect) occurs due to chance events
rather than fitness.
4. A structure that is similar in different species because of common ancestry is
called a:
A. Analogous structure
B. Homologous structure
C. Vestigial structure
,D. Fossilized structure
Rationale: Homologous structures (like the bones in a human arm and a whale
flipper) indicate a shared evolutionary past.
5. "Speciation" is defined as the:
A. Extinction of a species.
B. Formation of a new and distinct species.
C. Migration of a species.
D. Mutation of a single gene.
Rationale: Speciation occurs when populations become reproductively isolated and
diverge over time.
6. In an ecosystem, which organisms occupy the first trophic level?
A. Herbivores
B. Producers (Autotrophs)
C. Carnivores
D. Decomposers
Rationale: Producers (plants/algae) capture solar energy and form the base of all food
webs.
7. The "10% Rule" in ecology states that:
A. 10% of organisms go extinct every year.
B. Only about 10% of energy is transferred from one trophic level to the next.
C. 10% of a population must migrate.
D. Predators eat 10% of their body weight.
Rationale: Most energy is lost as heat; only 10% is available to the consumer at the
next level.
8. Which type of symbiotic relationship benefits one species while the other is
neither helped nor harmed?
A. Mutualism
B. Parasitism
C. Commensalism
D. Competition
Rationale: Commensalism (e.g., barnacles on a whale) is a neutral-positive
interaction.
9. "Carrying Capacity" is the:
A. Total number of species in the world.
B. Maximum population size an environment can sustain indefinitely.
C. Speed at which a population grows.
, D. Weight an animal can carry.
Rationale: Carrying capacity is limited by resources like food, water, and space.
10. Which of the following is a "Vestigial Structure" in humans?
A. The heart
B. The tailbone (coccyx)
C. The lungs
D. Biceps
Rationale: Vestigial structures are remnants of features that served a function in an
organism's ancestors.
11. "Gene Flow" refers to the:
A. Mutation of DNA.
B. Movement of alleles between populations due to migration.
C. Death of a population.
D. Cloning of a cell.
Rationale: Gene flow increases genetic diversity by introducing new alleles from other
areas.
12. An ecosystem consists of:
A. Only the living organisms.
B. Both the biotic (living) and abiotic (non-living) components.
C. Only the weather.
D. Only the plants.
Rationale: An ecosystem includes the community of organisms and their physical
environment (soil, water, air).
13. "Primary Succession" occurs in an area that:
A. Was previously a forest.
B. Has no soil (e.g., after a volcanic eruption).
C. Has been flooded.
D. Is currently underwater.
Rationale: Primary succession starts from bare rock and requires the slow build-up of
soil.
14. What is the primary cause of modern-day mass extinctions?
A. Volcanic eruptions
B. Human activity (habitat loss, climate change).
C. Asteroid impacts
D. Natural aging of species
Verified Q&As + Review Guide
The final comprehensive 100-question series for Module 6. This 2026 update focuses
on Darwinian Fitness, Allopatric Speciation, Trophic Energy Flow, Biogeochemical
Cycles, and Community Interactions. This set is the ultimate preparation tool for the BIOD
101 Final Exam.
1. Which scientist is credited with proposing the theory of Evolution by Natural
Selection?
A. Gregor Mendel
B. Charles Darwin
C. Jean-Baptiste Lamarck
D. Robert Hooke
Rationale: In his work On the Origin of Species, Darwin explained how favorable traits
lead to increased survival and reproduction.
2. "Natural Selection" can only occur if there is _______ within a population.
A. Perfect equality
B. Genetic variation
C. No competition
D. Unlimited food
Rationale: Without variation, there are no different traits for nature to "select" for or
against.
3. Which mechanism of evolution involves a random change in allele frequencies,
typically in small populations?
A. Natural Selection
B. Genetic Drift
C. Gene Flow
D. Mutation
Rationale: Genetic Drift (e.g., the Bottleneck Effect) occurs due to chance events
rather than fitness.
4. A structure that is similar in different species because of common ancestry is
called a:
A. Analogous structure
B. Homologous structure
C. Vestigial structure
,D. Fossilized structure
Rationale: Homologous structures (like the bones in a human arm and a whale
flipper) indicate a shared evolutionary past.
5. "Speciation" is defined as the:
A. Extinction of a species.
B. Formation of a new and distinct species.
C. Migration of a species.
D. Mutation of a single gene.
Rationale: Speciation occurs when populations become reproductively isolated and
diverge over time.
6. In an ecosystem, which organisms occupy the first trophic level?
A. Herbivores
B. Producers (Autotrophs)
C. Carnivores
D. Decomposers
Rationale: Producers (plants/algae) capture solar energy and form the base of all food
webs.
7. The "10% Rule" in ecology states that:
A. 10% of organisms go extinct every year.
B. Only about 10% of energy is transferred from one trophic level to the next.
C. 10% of a population must migrate.
D. Predators eat 10% of their body weight.
Rationale: Most energy is lost as heat; only 10% is available to the consumer at the
next level.
8. Which type of symbiotic relationship benefits one species while the other is
neither helped nor harmed?
A. Mutualism
B. Parasitism
C. Commensalism
D. Competition
Rationale: Commensalism (e.g., barnacles on a whale) is a neutral-positive
interaction.
9. "Carrying Capacity" is the:
A. Total number of species in the world.
B. Maximum population size an environment can sustain indefinitely.
C. Speed at which a population grows.
, D. Weight an animal can carry.
Rationale: Carrying capacity is limited by resources like food, water, and space.
10. Which of the following is a "Vestigial Structure" in humans?
A. The heart
B. The tailbone (coccyx)
C. The lungs
D. Biceps
Rationale: Vestigial structures are remnants of features that served a function in an
organism's ancestors.
11. "Gene Flow" refers to the:
A. Mutation of DNA.
B. Movement of alleles between populations due to migration.
C. Death of a population.
D. Cloning of a cell.
Rationale: Gene flow increases genetic diversity by introducing new alleles from other
areas.
12. An ecosystem consists of:
A. Only the living organisms.
B. Both the biotic (living) and abiotic (non-living) components.
C. Only the weather.
D. Only the plants.
Rationale: An ecosystem includes the community of organisms and their physical
environment (soil, water, air).
13. "Primary Succession" occurs in an area that:
A. Was previously a forest.
B. Has no soil (e.g., after a volcanic eruption).
C. Has been flooded.
D. Is currently underwater.
Rationale: Primary succession starts from bare rock and requires the slow build-up of
soil.
14. What is the primary cause of modern-day mass extinctions?
A. Volcanic eruptions
B. Human activity (habitat loss, climate change).
C. Asteroid impacts
D. Natural aging of species
