1
BIOD 210 FINAL EXAMINATION PORTAGE LEARNING (LATEST
2026/2027 UPDATE) ] ACTUAL QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026 Q&A
| INSTANT DOWNLOAD PDF
CORE DOMAINS
• Mendelian Inheritance and Pedigree Analysis
• Chromosomal Basis of Inheritance and Cytogenetics
• DNA Structure, Replication, and Repair
• Transcription, RNA Processing, and Translation
• Gene Regulation and Epigenetics
• Mutations, DNA Damage, and Carcinogenesis
• Genetic Technologies and Recombinant DNA
• Population Genetics and Evolutionary Principles
• Quantitative Genetics and Heritability
• Clinical Genetics and Ethical Considerations
This comprehensive final examination for BIOD 210 Genetics assesses the
fundamental and applied knowledge necessary to demonstrate mastery of
heredity and gene expression. The exam covers Mendelian principles,
chromosomal inheritance, molecular genetics, and cutting-edge biotechnological
applications. You will be evaluated on your ability to interpret pedigree data,
predict genotypic and phenotypic ratios, analyze DNA sequences, and apply
genetic concepts to real-world clinical and research scenarios. The 100 multiple-
choice questions emphasize critical thinking, problem-solving, and the integration
of genetic principles across multiple scales—from molecules to populations.
Success on this assessment requires a deep understanding of how genetic
information is stored, transmitted, and expressed, and how genetic variation
pg. 1
,2
contributes to health and disease. This examination is designed to mirror the rigor
and scope of a proctored final evaluation.
SECTION ONE: QUESTIONS 1–100
Question 1
A man who is heterozygous for a recessive autosomal trait mates with a woman
who is homozygous dominant for that trait. What proportion of their offspring
will express the recessive phenotype?
A. 0%
B. 25%
C. 50%
D. 100%
A. 0%
RATIONALE: The father's genotype is Aa, the mother's is AA. A Punnett square
yields 50% AA and 50% Aa. All offspring inherit at least one dominant allele, so
none will express the recessive phenotype. The recessive trait requires
homozygosity (aa), which cannot be produced from this cross.
Question 2
Which enzyme is responsible for relieving supercoiling ahead of the replication
fork during DNA replication?
A. Helicase
B. Primase
C. Topoisomerase (DNA gyrase)
D. DNA ligase
C. Topoisomerase (DNA gyrase)
RATIONALE: Topoisomerase (DNA gyrase in prokaryotes) cuts and reseals DNA
strands to relieve the torsional stress and supercoiling generated by helicase
unwinding the double helix. Helicase separates the strands, primase synthesizes
RNA primers, and ligase seals Okazaki fragments.
pg. 2
,3
Question 3
A pedigree shows an affected father who passes the trait to all his daughters but
to none of his sons. This pattern is most consistent with:
A. Autosomal dominant inheritance
B. Autosomal recessive inheritance
C. X-linked dominant inheritance
D. Y-linked inheritance
C. X-linked dominant inheritance
RATIONALE: In X-linked dominant inheritance, an affected male transmits the
mutant X chromosome to all daughters (who are XX) but not to sons (who receive
the Y chromosome). Affected daughters are heterozygous. Y-linked traits would
only be passed from father to son. Autosomal inheritance would affect sons and
daughters equally.
Question 4
A mutation changes a codon from GAG to GUG. This is an example of a:
A. Silent mutation
B. Missense mutation
C. Nonsense mutation
D. Frameshift mutation
B. Missense mutation
RATIONALE: A missense mutation is a single nucleotide change that results in
a codon that codes for a different amino acid. GAG codes for glutamate, GUG
codes for valine. This is the classic sickle-cell mutation (GAG to GUG). Silent
mutations do not change the amino acid, nonsense mutations create a stop
codon, and frameshifts alter the reading frame.
Question 5
Which of the following mechanisms is responsible for the ability of one gene to
produce multiple different protein products from a single primary transcript?
A. Operon regulation
B. Alternative splicing
pg. 3
, 4
C. DNA methylation
D. Histone acetylation
B. Alternative splicing
RATIONALE: Alternative splicing allows different exons to be joined together,
generating multiple mRNA isoforms from the same gene. This greatly increases
protein diversity without requiring additional genes. Operon regulation is
prokaryotic. DNA methylation and histone acetylation regulate transcription but
do not directly produce multiple isoforms from a single transcript.
Question 6
In a dihybrid cross between two individuals heterozygous for both traits (AaBb x
AaBb), what fraction of the offspring is expected to show the double recessive
phenotype (aabb)?
A. 1/16
B. 3/16
C. 9/16
D. 1/4
A. 1/16
RATIONALE: The expected phenotypic ratio for a dihybrid cross with
independent assortment is 9:3:3:1. The double recessive phenotype (aabb)
occupies 1 of the 16 possible genotype combinations, thus 1/16. The probability is
(1/4) × (1/4) = 1/16.
Question 7
Which process in meiosis is a primary contributor to genetic variation through the
physical exchange of chromosomal segments between homologous
chromosomes?
A. Independent assortment
B. Cytokinesis
C. Crossing over (recombination)
D. Separation of sister chromatids
C. Crossing over (recombination)
pg. 4
BIOD 210 FINAL EXAMINATION PORTAGE LEARNING (LATEST
2026/2027 UPDATE) ] ACTUAL QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026 Q&A
| INSTANT DOWNLOAD PDF
CORE DOMAINS
• Mendelian Inheritance and Pedigree Analysis
• Chromosomal Basis of Inheritance and Cytogenetics
• DNA Structure, Replication, and Repair
• Transcription, RNA Processing, and Translation
• Gene Regulation and Epigenetics
• Mutations, DNA Damage, and Carcinogenesis
• Genetic Technologies and Recombinant DNA
• Population Genetics and Evolutionary Principles
• Quantitative Genetics and Heritability
• Clinical Genetics and Ethical Considerations
This comprehensive final examination for BIOD 210 Genetics assesses the
fundamental and applied knowledge necessary to demonstrate mastery of
heredity and gene expression. The exam covers Mendelian principles,
chromosomal inheritance, molecular genetics, and cutting-edge biotechnological
applications. You will be evaluated on your ability to interpret pedigree data,
predict genotypic and phenotypic ratios, analyze DNA sequences, and apply
genetic concepts to real-world clinical and research scenarios. The 100 multiple-
choice questions emphasize critical thinking, problem-solving, and the integration
of genetic principles across multiple scales—from molecules to populations.
Success on this assessment requires a deep understanding of how genetic
information is stored, transmitted, and expressed, and how genetic variation
pg. 1
,2
contributes to health and disease. This examination is designed to mirror the rigor
and scope of a proctored final evaluation.
SECTION ONE: QUESTIONS 1–100
Question 1
A man who is heterozygous for a recessive autosomal trait mates with a woman
who is homozygous dominant for that trait. What proportion of their offspring
will express the recessive phenotype?
A. 0%
B. 25%
C. 50%
D. 100%
A. 0%
RATIONALE: The father's genotype is Aa, the mother's is AA. A Punnett square
yields 50% AA and 50% Aa. All offspring inherit at least one dominant allele, so
none will express the recessive phenotype. The recessive trait requires
homozygosity (aa), which cannot be produced from this cross.
Question 2
Which enzyme is responsible for relieving supercoiling ahead of the replication
fork during DNA replication?
A. Helicase
B. Primase
C. Topoisomerase (DNA gyrase)
D. DNA ligase
C. Topoisomerase (DNA gyrase)
RATIONALE: Topoisomerase (DNA gyrase in prokaryotes) cuts and reseals DNA
strands to relieve the torsional stress and supercoiling generated by helicase
unwinding the double helix. Helicase separates the strands, primase synthesizes
RNA primers, and ligase seals Okazaki fragments.
pg. 2
,3
Question 3
A pedigree shows an affected father who passes the trait to all his daughters but
to none of his sons. This pattern is most consistent with:
A. Autosomal dominant inheritance
B. Autosomal recessive inheritance
C. X-linked dominant inheritance
D. Y-linked inheritance
C. X-linked dominant inheritance
RATIONALE: In X-linked dominant inheritance, an affected male transmits the
mutant X chromosome to all daughters (who are XX) but not to sons (who receive
the Y chromosome). Affected daughters are heterozygous. Y-linked traits would
only be passed from father to son. Autosomal inheritance would affect sons and
daughters equally.
Question 4
A mutation changes a codon from GAG to GUG. This is an example of a:
A. Silent mutation
B. Missense mutation
C. Nonsense mutation
D. Frameshift mutation
B. Missense mutation
RATIONALE: A missense mutation is a single nucleotide change that results in
a codon that codes for a different amino acid. GAG codes for glutamate, GUG
codes for valine. This is the classic sickle-cell mutation (GAG to GUG). Silent
mutations do not change the amino acid, nonsense mutations create a stop
codon, and frameshifts alter the reading frame.
Question 5
Which of the following mechanisms is responsible for the ability of one gene to
produce multiple different protein products from a single primary transcript?
A. Operon regulation
B. Alternative splicing
pg. 3
, 4
C. DNA methylation
D. Histone acetylation
B. Alternative splicing
RATIONALE: Alternative splicing allows different exons to be joined together,
generating multiple mRNA isoforms from the same gene. This greatly increases
protein diversity without requiring additional genes. Operon regulation is
prokaryotic. DNA methylation and histone acetylation regulate transcription but
do not directly produce multiple isoforms from a single transcript.
Question 6
In a dihybrid cross between two individuals heterozygous for both traits (AaBb x
AaBb), what fraction of the offspring is expected to show the double recessive
phenotype (aabb)?
A. 1/16
B. 3/16
C. 9/16
D. 1/4
A. 1/16
RATIONALE: The expected phenotypic ratio for a dihybrid cross with
independent assortment is 9:3:3:1. The double recessive phenotype (aabb)
occupies 1 of the 16 possible genotype combinations, thus 1/16. The probability is
(1/4) × (1/4) = 1/16.
Question 7
Which process in meiosis is a primary contributor to genetic variation through the
physical exchange of chromosomal segments between homologous
chromosomes?
A. Independent assortment
B. Cytokinesis
C. Crossing over (recombination)
D. Separation of sister chromatids
C. Crossing over (recombination)
pg. 4
