BIO111 Final Exam Actual Exam V1 | BIO111 General Biology (BIO111
Final Exam) | UCLA
1. Which property of water allows it to move from the roots to the leaves of a tall tree against
gravity?
A. High specific heat capacity
B. High heat of vaporization
C. Low density of ice compared to liquid water
D. Cohesion and adhesion through hydrogen bonding
Answer: D
Rationale: Cohesion allows water molecules to stick to each other, while adhesion allows
them to stick to the xylem walls. These properties work together to form a continuous
water column. This capillary action is essential for nutrient transport in vascular plants.
2. During which phase of the cell cycle is DNA replicated to ensure daughter cells receive a
complete genome?
A. S Phase
B. G1 Phase
C. G2 Phase
D. M Phase
Answer: A
Rationale: The S phase, or synthesis phase, is the specific period during interphase where
DNA synthesis occurs. Each chromosome is duplicated to form sister chromatids. This step
is critical before the cell enters mitosis to divide its genetic material.
3. What is the primary function of the enzyme ATP synthase in the mitochondrial inner
membrane?
A. To oxidize glucose into pyruvate
B. To use the proton motive force to synthesize ATP
C. To pump protons into the intermembrane space
D. To reduce oxygen to form water
Answer: B
,Rationale: ATP synthase acts as a molecular motor that utilizes the flow of protons down
their concentration gradient. This process is known as chemiosmosis. It converts
mechanical energy into chemical energy stored in ATP molecules.
4. Which of the following describes a scenario of allopatric speciation?
A. A population of flies begins to feed on different host plants within the same forest.
B. Sexual selection leads to distinct mating preferences in a single lake population.
C. Polyploidy occurs in a plant population, making them unable to breed with parent types.
D. A mountain range forms, physically isolating two populations of a ground-dwelling
beetle.
Answer: D
Rationale: Allopatric speciation occurs when a geographic barrier prevents gene flow
between populations. Over time, genetic drift and natural selection cause the populations
to diverge. If the barrier is removed, the two groups may no longer be able to interbreed.
5. In a Mendelian cross between two heterozygous purple-flowered pea plants (Pp), what is
the expected phenotypic ratio of the offspring?
A. 1:1 Purple to White
B. All Purple
C. 1:2:1 Purple to White
D. 3:1 Purple to White
Answer: D
Rationale: A cross between Pp and Pp results in genotypes PP, Pp, Pp, and pp. Since purple
is dominant, the PP and Pp individuals will all show the purple phenotype. This results in a
75% chance of purple and a 25% chance of white offspring.
6. What is the primary role of tRNA during the process of translation?
A. To carry the genetic code from the nucleus to the ribosome
B. To deliver specific amino acids to the growing polypeptide chain
C. To catalyze the formation of the peptide bond
D. To synthesize mRNA from a DNA template
Answer: B
Rationale: Transfer RNA (tRNA) molecules possess an anticodon that matches a specific
mRNA codon. They carry the corresponding amino acid to the ribosome for incorporation.
This ensures that the genetic sequence is accurately translated into a protein.
, 7. Which statement best describes the ‘Fluid Mosaic Model’ of the cell membrane?
A. A rigid layer of proteins surrounding a liquid lipid core
B. A bilayer of phospholipids with embedded proteins that can move laterally
C. A solid structure composed entirely of carbohydrates and cholesterol
D. A single layer of proteins that acts as a gatekeeper for all molecules
Answer: B
Rationale: The ‘fluid’ part of the model refers to the lateral movement of phospholipids
and proteins within the membrane. The ‘mosaic’ part refers to the various proteins,
carbohydrates, and lipids embedded in the bilayer. This structure is essential for
maintaining cell homeostasis and signaling.
8. If a segment of DNA has the sequence 5’-ATTGCA-3’, what is the complementary mRNA
sequence produced during transcription?
A. 5’-UAACGU-3’
B. 3’-TAACGT-5’
C. 5’-TAACGT-3’
D. 3’-UAACGU-5’
Answer: D
Rationale: Transcription produces RNA in the 5’ to 3’ direction, complementary to the 3’ to
5’ DNA template strand. Since the prompt gives the coding strand (5’ to 3’), the mRNA will
match the coding strand but replace Thymine with Uracil. Therefore, the mRNA sequence is
5’-AUUGCA-3’, which is equivalent to 3’-ACGUUA-5’ if reversed, but standard matching to
the template 3’-TAACGT-5’ yields 5’-AUUGCA-3’.
9. Which metabolic pathway is common to both aerobic respiration and fermentation?
A. The Citric Acid Cycle
B. Oxidative Phosphorylation
C. Glycolysis
D. The Electron Transport Chain
Answer: C
Rationale: Glycolysis occurs in the cytosol and does not require oxygen to function. It
breaks down glucose into two molecules of pyruvate, producing a net gain of 2 ATP.
Because it is independent of oxygen, it serves as the first step for both aerobic and
anaerobic pathways.
Final Exam) | UCLA
1. Which property of water allows it to move from the roots to the leaves of a tall tree against
gravity?
A. High specific heat capacity
B. High heat of vaporization
C. Low density of ice compared to liquid water
D. Cohesion and adhesion through hydrogen bonding
Answer: D
Rationale: Cohesion allows water molecules to stick to each other, while adhesion allows
them to stick to the xylem walls. These properties work together to form a continuous
water column. This capillary action is essential for nutrient transport in vascular plants.
2. During which phase of the cell cycle is DNA replicated to ensure daughter cells receive a
complete genome?
A. S Phase
B. G1 Phase
C. G2 Phase
D. M Phase
Answer: A
Rationale: The S phase, or synthesis phase, is the specific period during interphase where
DNA synthesis occurs. Each chromosome is duplicated to form sister chromatids. This step
is critical before the cell enters mitosis to divide its genetic material.
3. What is the primary function of the enzyme ATP synthase in the mitochondrial inner
membrane?
A. To oxidize glucose into pyruvate
B. To use the proton motive force to synthesize ATP
C. To pump protons into the intermembrane space
D. To reduce oxygen to form water
Answer: B
,Rationale: ATP synthase acts as a molecular motor that utilizes the flow of protons down
their concentration gradient. This process is known as chemiosmosis. It converts
mechanical energy into chemical energy stored in ATP molecules.
4. Which of the following describes a scenario of allopatric speciation?
A. A population of flies begins to feed on different host plants within the same forest.
B. Sexual selection leads to distinct mating preferences in a single lake population.
C. Polyploidy occurs in a plant population, making them unable to breed with parent types.
D. A mountain range forms, physically isolating two populations of a ground-dwelling
beetle.
Answer: D
Rationale: Allopatric speciation occurs when a geographic barrier prevents gene flow
between populations. Over time, genetic drift and natural selection cause the populations
to diverge. If the barrier is removed, the two groups may no longer be able to interbreed.
5. In a Mendelian cross between two heterozygous purple-flowered pea plants (Pp), what is
the expected phenotypic ratio of the offspring?
A. 1:1 Purple to White
B. All Purple
C. 1:2:1 Purple to White
D. 3:1 Purple to White
Answer: D
Rationale: A cross between Pp and Pp results in genotypes PP, Pp, Pp, and pp. Since purple
is dominant, the PP and Pp individuals will all show the purple phenotype. This results in a
75% chance of purple and a 25% chance of white offspring.
6. What is the primary role of tRNA during the process of translation?
A. To carry the genetic code from the nucleus to the ribosome
B. To deliver specific amino acids to the growing polypeptide chain
C. To catalyze the formation of the peptide bond
D. To synthesize mRNA from a DNA template
Answer: B
Rationale: Transfer RNA (tRNA) molecules possess an anticodon that matches a specific
mRNA codon. They carry the corresponding amino acid to the ribosome for incorporation.
This ensures that the genetic sequence is accurately translated into a protein.
, 7. Which statement best describes the ‘Fluid Mosaic Model’ of the cell membrane?
A. A rigid layer of proteins surrounding a liquid lipid core
B. A bilayer of phospholipids with embedded proteins that can move laterally
C. A solid structure composed entirely of carbohydrates and cholesterol
D. A single layer of proteins that acts as a gatekeeper for all molecules
Answer: B
Rationale: The ‘fluid’ part of the model refers to the lateral movement of phospholipids
and proteins within the membrane. The ‘mosaic’ part refers to the various proteins,
carbohydrates, and lipids embedded in the bilayer. This structure is essential for
maintaining cell homeostasis and signaling.
8. If a segment of DNA has the sequence 5’-ATTGCA-3’, what is the complementary mRNA
sequence produced during transcription?
A. 5’-UAACGU-3’
B. 3’-TAACGT-5’
C. 5’-TAACGT-3’
D. 3’-UAACGU-5’
Answer: D
Rationale: Transcription produces RNA in the 5’ to 3’ direction, complementary to the 3’ to
5’ DNA template strand. Since the prompt gives the coding strand (5’ to 3’), the mRNA will
match the coding strand but replace Thymine with Uracil. Therefore, the mRNA sequence is
5’-AUUGCA-3’, which is equivalent to 3’-ACGUUA-5’ if reversed, but standard matching to
the template 3’-TAACGT-5’ yields 5’-AUUGCA-3’.
9. Which metabolic pathway is common to both aerobic respiration and fermentation?
A. The Citric Acid Cycle
B. Oxidative Phosphorylation
C. Glycolysis
D. The Electron Transport Chain
Answer: C
Rationale: Glycolysis occurs in the cytosol and does not require oxygen to function. It
breaks down glucose into two molecules of pyruvate, producing a net gain of 2 ATP.
Because it is independent of oxygen, it serves as the first step for both aerobic and
anaerobic pathways.
