BIO 189 Final Exam: Fundamentals of Biology V3 - Arizona
College Updated and Latest Questions and Correct
Answers with Rationale
1. Which of the following properties of water allows it to move upward through a plant’s vascular system
against gravity?
A. High specific heat
B. Cohesion and adhesion
C. Density as a solid
D. Universal solvency
Ans: B
Explanation: Cohesion refers to the attraction between water molecules while adhesion is the attraction
between water and the xylem walls. These two forces work together to create a continuous column of
water. As water evaporates from leaves, it pulls the column upward due to surface tension. This
phenomenon is commonly known as capillary action. Without these hydrogen-bonding properties, tall
vascular plants could not survive.
2. In a cell, which organelle is responsible for the modification, sorting, and packaging of proteins for
secretion?
A. Golgi Apparatus
B. Smooth Endoplasmic Reticulum
C. Nucleus
D. Lysosome
Ans: A
,Explanation: The Golgi apparatus functions as the post office of the eukaryotic cell. It receives proteins
from the rough endoplasmic reticulum and modifies them chemically. After modification, it sorts these
proteins into vesicles based on their destination. Some vesicles lead to the plasma membrane while
others stay within the cell. This process is vital for ensuring that enzymes and hormones reach their
required locations.
3. During which phase of the cell cycle is DNA replicated to ensure daughter cells receive a full set of genetic
material?
A. G1 phase
B. S phase
C. G2 phase
D. M phase
Ans: B
Explanation: The S phase, or synthesis phase, is a critical part of interphase in the cell cycle. During this
time, the cell copies its entire genome through DNA replication. This ensures that when the cell
eventually divides, each new nucleus contains an identical copy of DNA. Checkpoints exist to verify that
replication is complete before the cell proceeds to G2. Proper regulation of the S phase prevents
chromosomal abnormalities and potential cancerous growth.
4. What is the primary role of molecular oxygen (O2) in aerobic cellular respiration?
A. It catalyzes the phosphorylation of ADP to ATP.
B. It breaks down glucose into pyruvate during glycolysis.
C. It provides the carbon atoms for the formation of CO2.
D. It acts as the final electron acceptor in the electron transport chain.
, Ans: D
Explanation: Oxygen is essential for aerobic organisms because of its high electronegativity. At the end
of the electron transport chain, oxygen accepts spent electrons and hydrogen ions to form water. This
allows the chain to continue pumping protons to maintain the electrochemical gradient. Without oxygen,
the chain stops and the cell must rely on less efficient fermentation. Thus, oxygen’s role is critical for
maximizing ATP production during oxidative phosphorylation.
5. A heterozygous purple-flowered pea plant (Pp) is crossed with a white-flowered pea plant (pp). What is
the probability of obtaining white-flowered offspring?
A. 0%
B. 25%
C. 50%
D. 100%
Ans: C
Explanation: In this test cross, the alleles from the purple parent (P and p) segregate during gamete
formation. The white parent can only contribute a recessive allele (p) to its gametes. Using a Punnett
square, we find the resulting genotypes are 50 percent Pp and 50 percent pp. Since ‘p’ is recessive, only
the ‘pp’ individuals will express the white flower phenotype. Therefore, there is a one-in-two chance that
any given offspring will be white.
6. Which process results in the production of two genetically identical diploid daughter cells?
A. Meiosis I
B. Mitosis
C. Meiosis II
College Updated and Latest Questions and Correct
Answers with Rationale
1. Which of the following properties of water allows it to move upward through a plant’s vascular system
against gravity?
A. High specific heat
B. Cohesion and adhesion
C. Density as a solid
D. Universal solvency
Ans: B
Explanation: Cohesion refers to the attraction between water molecules while adhesion is the attraction
between water and the xylem walls. These two forces work together to create a continuous column of
water. As water evaporates from leaves, it pulls the column upward due to surface tension. This
phenomenon is commonly known as capillary action. Without these hydrogen-bonding properties, tall
vascular plants could not survive.
2. In a cell, which organelle is responsible for the modification, sorting, and packaging of proteins for
secretion?
A. Golgi Apparatus
B. Smooth Endoplasmic Reticulum
C. Nucleus
D. Lysosome
Ans: A
,Explanation: The Golgi apparatus functions as the post office of the eukaryotic cell. It receives proteins
from the rough endoplasmic reticulum and modifies them chemically. After modification, it sorts these
proteins into vesicles based on their destination. Some vesicles lead to the plasma membrane while
others stay within the cell. This process is vital for ensuring that enzymes and hormones reach their
required locations.
3. During which phase of the cell cycle is DNA replicated to ensure daughter cells receive a full set of genetic
material?
A. G1 phase
B. S phase
C. G2 phase
D. M phase
Ans: B
Explanation: The S phase, or synthesis phase, is a critical part of interphase in the cell cycle. During this
time, the cell copies its entire genome through DNA replication. This ensures that when the cell
eventually divides, each new nucleus contains an identical copy of DNA. Checkpoints exist to verify that
replication is complete before the cell proceeds to G2. Proper regulation of the S phase prevents
chromosomal abnormalities and potential cancerous growth.
4. What is the primary role of molecular oxygen (O2) in aerobic cellular respiration?
A. It catalyzes the phosphorylation of ADP to ATP.
B. It breaks down glucose into pyruvate during glycolysis.
C. It provides the carbon atoms for the formation of CO2.
D. It acts as the final electron acceptor in the electron transport chain.
, Ans: D
Explanation: Oxygen is essential for aerobic organisms because of its high electronegativity. At the end
of the electron transport chain, oxygen accepts spent electrons and hydrogen ions to form water. This
allows the chain to continue pumping protons to maintain the electrochemical gradient. Without oxygen,
the chain stops and the cell must rely on less efficient fermentation. Thus, oxygen’s role is critical for
maximizing ATP production during oxidative phosphorylation.
5. A heterozygous purple-flowered pea plant (Pp) is crossed with a white-flowered pea plant (pp). What is
the probability of obtaining white-flowered offspring?
A. 0%
B. 25%
C. 50%
D. 100%
Ans: C
Explanation: In this test cross, the alleles from the purple parent (P and p) segregate during gamete
formation. The white parent can only contribute a recessive allele (p) to its gametes. Using a Punnett
square, we find the resulting genotypes are 50 percent Pp and 50 percent pp. Since ‘p’ is recessive, only
the ‘pp’ individuals will express the white flower phenotype. Therefore, there is a one-in-two chance that
any given offspring will be white.
6. Which process results in the production of two genetically identical diploid daughter cells?
A. Meiosis I
B. Mitosis
C. Meiosis II
