BIOLOGY 152 UWM EXAM 1: FOUNDATIONS
OF BIOLOGICAL SCIENCES II, (LATEST
2026/2027 UPDATE) QUESTIONS AND
ANSWERS | GRADE A | 100% CORRECT
AT THE UNIVERSITY OF WISCONSIN-
MILWAUKEE (UWM)
Biology 152 UWM – Exam 1 (2026/2027)
1. Before cyanobacteria evolved oxygenic photosynthesis, life on
Earth was primarily:
A. Aerobic
B. Anaerobic
C. Multicellular
D. Photosynthetic
Correct Answer: B. Anaerobic
Rationale: Early Earth lacked free oxygen in its atmosphere. Life forms relied on
anaerobic metabolic pathways for energy production. Cyanobacteria later introduced
oxygen through oxygenic photosynthesis. This dramatically changed Earth’s
atmosphere and enabled aerobic metabolism.
2. The presence of oxygen allows cells to generate more:
A. NADH
B. DNA
C. ATP
D. Glucose
Correct Answer: C. ATP
,Rationale: Oxygen serves as the terminal electron acceptor in aerobic respiration.
This allows oxidative phosphorylation to produce large amounts of ATP. Anaerobic
pathways generate significantly less ATP. Therefore, oxygen increases energy
efficiency.
3. Increased oxygen availability ultimately led to:
A. Smaller cells
B. Simpler metabolism
C. More complex life forms
D. Elimination of microbes
Correct Answer: C. More complex life forms
Rationale: Greater ATP production supports higher cellular complexity. Eukaryotic
cells require substantial energy to maintain organelles. Oxygen-rich environments
enabled multicellularity. Complexity increased as energy became more available.
4. The majority of life on Earth is composed of:
A. Animals
B. Plants
C. Fungi
D. Microbes (bacteria and archaea)
Correct Answer: D. Microbes (bacteria and archaea)
Rationale: Microorganisms dominate Earth in both biomass and diversity. They
inhabit extreme and common environments alike. Bacteria and archaea represent
ancient life forms. Multicellular organisms are comparatively rare.
5. Eukaryotic cells differ from prokaryotic cells because they
contain:
A. Ribosomes
B. DNA
C. A nucleus and membrane-bound organelles
D. A plasma membrane
Correct Answer: C. A nucleus and membrane-bound organelles
,Rationale: Eukaryotes possess a defined nucleus containing genetic material. They
also have organelles such as mitochondria and chloroplasts. Prokaryotes lack
membrane-bound compartments. This structural difference defines the two groups.
6. Eukaryotes are believed to have evolved from:
A. Viruses
B. Fungi
C. Prokaryotic bacteria
D. Plants
Correct Answer: C. Prokaryotic bacteria
Rationale: Molecular and genetic evidence supports a bacterial ancestry. The
endosymbiotic theory explains organelle origins. Mitochondria and chloroplasts
resemble bacteria. Therefore, eukaryotes evolved from prokaryotic ancestors.
7. Endosymbiosis refers to:
A. Cells dividing equally
B. A cell engulfing another cell and retaining its traits
C. Viral infection
D. Binary fission
Correct Answer: B. A cell engulfing another cell and retaining its traits
Rationale: Endosymbiosis explains organelle evolution. An ancestral host cell
engulfed bacteria. Instead of digesting them, it formed a mutualistic relationship.
These bacteria evolved into mitochondria and chloroplasts.
8. Bacteria are classified as:
A. Multicellular organisms
B. Unicellular organisms
C. Acellular particles
D. Colonial fungi
Correct Answer: B. Unicellular organisms
, Rationale: Each bacterium is a single cell. They perform all life functions
independently. Though unicellular, they can form colonies. Their simplicity does not
limit survival ability.
9. Although bacteria are unicellular, they can exhibit development
and social interactions.
A. True
B. False
Correct Answer: A. True
Rationale: Bacteria form biofilms and communicate chemically. Quorum sensing
allows population-based coordination. They can differentiate into specialized cell
types. Social behaviors increase survival.
10. Bacteria are used in biotechnology to generate:
A. Hybrid plants
B. Transgenic plants
C. Fossil fuels
D. Antibiotics only
Correct Answer: B. Transgenic plants
Rationale: Bacteria such as Agrobacterium transfer genes into plants. This allows
genetic modification. Transgenic plants may resist pests or tolerate drought. Bacteria
are valuable genetic tools.
11. Bacteria are widely utilized for which environmental application?
A. Photosynthesis
B. Bioremediation
C. Viral replication
D. Fossil fuel production
Correct Answer: B. Bioremediation
Rationale: Bioremediation involves using microorganisms to remove pollutants from
the environment. Many bacteria can metabolize toxic compounds such as oil spills or
OF BIOLOGICAL SCIENCES II, (LATEST
2026/2027 UPDATE) QUESTIONS AND
ANSWERS | GRADE A | 100% CORRECT
AT THE UNIVERSITY OF WISCONSIN-
MILWAUKEE (UWM)
Biology 152 UWM – Exam 1 (2026/2027)
1. Before cyanobacteria evolved oxygenic photosynthesis, life on
Earth was primarily:
A. Aerobic
B. Anaerobic
C. Multicellular
D. Photosynthetic
Correct Answer: B. Anaerobic
Rationale: Early Earth lacked free oxygen in its atmosphere. Life forms relied on
anaerobic metabolic pathways for energy production. Cyanobacteria later introduced
oxygen through oxygenic photosynthesis. This dramatically changed Earth’s
atmosphere and enabled aerobic metabolism.
2. The presence of oxygen allows cells to generate more:
A. NADH
B. DNA
C. ATP
D. Glucose
Correct Answer: C. ATP
,Rationale: Oxygen serves as the terminal electron acceptor in aerobic respiration.
This allows oxidative phosphorylation to produce large amounts of ATP. Anaerobic
pathways generate significantly less ATP. Therefore, oxygen increases energy
efficiency.
3. Increased oxygen availability ultimately led to:
A. Smaller cells
B. Simpler metabolism
C. More complex life forms
D. Elimination of microbes
Correct Answer: C. More complex life forms
Rationale: Greater ATP production supports higher cellular complexity. Eukaryotic
cells require substantial energy to maintain organelles. Oxygen-rich environments
enabled multicellularity. Complexity increased as energy became more available.
4. The majority of life on Earth is composed of:
A. Animals
B. Plants
C. Fungi
D. Microbes (bacteria and archaea)
Correct Answer: D. Microbes (bacteria and archaea)
Rationale: Microorganisms dominate Earth in both biomass and diversity. They
inhabit extreme and common environments alike. Bacteria and archaea represent
ancient life forms. Multicellular organisms are comparatively rare.
5. Eukaryotic cells differ from prokaryotic cells because they
contain:
A. Ribosomes
B. DNA
C. A nucleus and membrane-bound organelles
D. A plasma membrane
Correct Answer: C. A nucleus and membrane-bound organelles
,Rationale: Eukaryotes possess a defined nucleus containing genetic material. They
also have organelles such as mitochondria and chloroplasts. Prokaryotes lack
membrane-bound compartments. This structural difference defines the two groups.
6. Eukaryotes are believed to have evolved from:
A. Viruses
B. Fungi
C. Prokaryotic bacteria
D. Plants
Correct Answer: C. Prokaryotic bacteria
Rationale: Molecular and genetic evidence supports a bacterial ancestry. The
endosymbiotic theory explains organelle origins. Mitochondria and chloroplasts
resemble bacteria. Therefore, eukaryotes evolved from prokaryotic ancestors.
7. Endosymbiosis refers to:
A. Cells dividing equally
B. A cell engulfing another cell and retaining its traits
C. Viral infection
D. Binary fission
Correct Answer: B. A cell engulfing another cell and retaining its traits
Rationale: Endosymbiosis explains organelle evolution. An ancestral host cell
engulfed bacteria. Instead of digesting them, it formed a mutualistic relationship.
These bacteria evolved into mitochondria and chloroplasts.
8. Bacteria are classified as:
A. Multicellular organisms
B. Unicellular organisms
C. Acellular particles
D. Colonial fungi
Correct Answer: B. Unicellular organisms
, Rationale: Each bacterium is a single cell. They perform all life functions
independently. Though unicellular, they can form colonies. Their simplicity does not
limit survival ability.
9. Although bacteria are unicellular, they can exhibit development
and social interactions.
A. True
B. False
Correct Answer: A. True
Rationale: Bacteria form biofilms and communicate chemically. Quorum sensing
allows population-based coordination. They can differentiate into specialized cell
types. Social behaviors increase survival.
10. Bacteria are used in biotechnology to generate:
A. Hybrid plants
B. Transgenic plants
C. Fossil fuels
D. Antibiotics only
Correct Answer: B. Transgenic plants
Rationale: Bacteria such as Agrobacterium transfer genes into plants. This allows
genetic modification. Transgenic plants may resist pests or tolerate drought. Bacteria
are valuable genetic tools.
11. Bacteria are widely utilized for which environmental application?
A. Photosynthesis
B. Bioremediation
C. Viral replication
D. Fossil fuel production
Correct Answer: B. Bioremediation
Rationale: Bioremediation involves using microorganisms to remove pollutants from
the environment. Many bacteria can metabolize toxic compounds such as oil spills or
