BIOL 101 Quiz 3 V2 | BIOL 101 Principles of
Biology | Actual Q&A with Rationale (BIOL101 Quiz
3) | Liberty University
1. Which enzyme is primarily responsible for adding new nucleotides to a growing DNA strand
during the process of replication?
A. Helicase
B. DNA Ligase
C. RNA Primase
D. DNA Polymerase
Correct Answer: D
Explanation: DNA Polymerase is the enzyme that catalyzes the synthesis of new DNA by
adding nucleotides to the 3’ end of a pre-existing chain. It requires a primer and a DNA
template strand to function accurately. This process is essential for ensuring that genetic
information is duplicated prior to cell division.
2. During which specific phase of the eukaryotic cell cycle does DNA replication occur?
A. S Phase
B. G1 Phase
C. G2 Phase
D. M Phase
,Correct Answer: A
Explanation: The S phase, or synthesis phase, is the part of the cell cycle dedicated to the
replication of nuclear DNA. By the end of this phase, each chromosome consists of two
identical sister chromatids attached at a centromere. This ensures that both daughter cells
will receive a complete genome after mitosis.
3. In a classic Mendelian monohybrid cross between two heterozygous (Pp) pea plants, what
is the expected phenotypic ratio of the F2 generation?
A. 3:1
B. 1:2:1
C. 9:3:3:1
D. 1:1
Correct Answer: A
Explanation: A monohybrid cross between two heterozygotes typically results in three-
fourths of the offspring displaying the dominant phenotype and one-fourth displaying the
recessive phenotype. This 3:1 ratio is a fundamental principle of Mendelian genetics. It
reflects the underlying 1:2:1 genotypic ratio of homozygous dominant, heterozygous, and
homozygous recessive individuals.
4. Which cellular structure serves as the primary site for the translation of mRNA into a
polypeptide chain?
A. Nucleus
, B. Golgi Apparatus
C. Lysosome
D. Ribosome
Correct Answer: D
Explanation: Ribosomes are the molecular machines responsible for protein synthesis in
all living cells. They facilitate the coupling of tRNA anticodons with mRNA codons to
assemble amino acids into a specific sequence. This process occurs in the cytoplasm or on
the surface of the rough endoplasmic reticulum.
5. What is the end result of the process of meiosis in a human cell?
A. Two identical diploid daughter cells
B. Four genetically unique haploid daughter cells
C. Two genetically unique haploid daughter cells
D. Four identical diploid daughter cells
Correct Answer: B
Explanation: Meiosis involves two successive rounds of cell division that reduce the
chromosome number by half. This results in four haploid gametes, each containing a single
set of 23 chromosomes. Genetic variation is introduced during this process through
crossing over and independent assortment.
Biology | Actual Q&A with Rationale (BIOL101 Quiz
3) | Liberty University
1. Which enzyme is primarily responsible for adding new nucleotides to a growing DNA strand
during the process of replication?
A. Helicase
B. DNA Ligase
C. RNA Primase
D. DNA Polymerase
Correct Answer: D
Explanation: DNA Polymerase is the enzyme that catalyzes the synthesis of new DNA by
adding nucleotides to the 3’ end of a pre-existing chain. It requires a primer and a DNA
template strand to function accurately. This process is essential for ensuring that genetic
information is duplicated prior to cell division.
2. During which specific phase of the eukaryotic cell cycle does DNA replication occur?
A. S Phase
B. G1 Phase
C. G2 Phase
D. M Phase
,Correct Answer: A
Explanation: The S phase, or synthesis phase, is the part of the cell cycle dedicated to the
replication of nuclear DNA. By the end of this phase, each chromosome consists of two
identical sister chromatids attached at a centromere. This ensures that both daughter cells
will receive a complete genome after mitosis.
3. In a classic Mendelian monohybrid cross between two heterozygous (Pp) pea plants, what
is the expected phenotypic ratio of the F2 generation?
A. 3:1
B. 1:2:1
C. 9:3:3:1
D. 1:1
Correct Answer: A
Explanation: A monohybrid cross between two heterozygotes typically results in three-
fourths of the offspring displaying the dominant phenotype and one-fourth displaying the
recessive phenotype. This 3:1 ratio is a fundamental principle of Mendelian genetics. It
reflects the underlying 1:2:1 genotypic ratio of homozygous dominant, heterozygous, and
homozygous recessive individuals.
4. Which cellular structure serves as the primary site for the translation of mRNA into a
polypeptide chain?
A. Nucleus
, B. Golgi Apparatus
C. Lysosome
D. Ribosome
Correct Answer: D
Explanation: Ribosomes are the molecular machines responsible for protein synthesis in
all living cells. They facilitate the coupling of tRNA anticodons with mRNA codons to
assemble amino acids into a specific sequence. This process occurs in the cytoplasm or on
the surface of the rough endoplasmic reticulum.
5. What is the end result of the process of meiosis in a human cell?
A. Two identical diploid daughter cells
B. Four genetically unique haploid daughter cells
C. Two genetically unique haploid daughter cells
D. Four identical diploid daughter cells
Correct Answer: B
Explanation: Meiosis involves two successive rounds of cell division that reduce the
chromosome number by half. This results in four haploid gametes, each containing a single
set of 23 chromosomes. Genetic variation is introduced during this process through
crossing over and independent assortment.
