BIOD 210 Module 2 Exam – Genetics (Portage Learning) (2026)
Actual Questions with Verified Answers | Take & Pass the Exam
Questions 1–70+
1. Which of the following statements is correct regarding Mendel's unit factors?
A) Mendel's label of "unit factors" are what we now refer to as chromosomes.
B) Genetic characteristics are controlled by unit factors that exist in pairs.
C) Each gamete carries both unit factors for a trait.
D) Unit factors are always identical to the phenotype.
Answer B: Genetic characteristics are controlled by unit factors that exist in pairs.
Rationale: Mendel's first postulate states that each trait is controlled by "unit factors" (alleles) that occur in
pairs in individual organisms.
2. True or False: A dominant gene will always cause the expression of a dominant phenotype in the
case of complete dominance.
A) True
B) False
Answer A: True
Rationale: Under complete dominance, a single dominant allele is sufficient for the dominant phenotype to
be expressed; the recessive allele's effect is masked in the heterozygote.
3. The defect that causes sickle-cell disease is due to a genetic mutation in which of the following?
A) Ferritin
B) AB glycoprotein
C) β-globulin
D) Sugar molecules on the cell surface
Answer C: β-globulin
Rationale: Sickle-cell disease arises from a single amino-acid substitution (point mutation) in the β-globin
protein of hemoglobin.
,4. A karyotype is a snapshot of the ______ within the cell.
A) DNA; liver; diploid
B) proteins; skin; identical
C) chromosomes; white blood cells; homologous (paired)
D) genes; muscle; single
Answer C: chromosomes; white blood cells; homologous (paired)
Rationale: Karyotyping visualizes chromosomes, typically from metaphase white blood cells, arranged into
homologous pairs to identify structural or numerical chromosomal abnormalities.
5. True or False: A normal chromosome set always has paired X and Y chromosomes.
A) True
B) False
Answer B: False
Rationale: Normal females have XX and normal males have XY; only males possess both X and Y. Thus a
"normal chromosome set" does not always include paired X and Y chromosomes.
6. The phenotype for ______ is distortion of the red blood cells in afflicted people. This results in
depletion of ______ in the blood and poses a significant risk to the patients at ______ altitude.
A) thalassemia; iron; low
B) sickle-cell anemia; oxygen; high
C) malaria; platelets; sea
D) hemophilia; calcium; high
Answer B: sickle-cell anemia; oxygen; high
Rationale: In sickle-cell anemia, deoxygenated hemoglobin S polymerizes, distorting RBCs, lowering oxygen
delivery, and making high altitudes especially dangerous.
7. Two individuals with widow's peaks have a child with a straight hairline. True or False: The gene
for a widow's peak is likely recessive?
A) True
B) False
Answer B: False
, Rationale: Because two parents with widow's peaks produced a straight-hairline child, widow's peak must
be dominant (W) and straight hair recessive (w); both parents are Ww.
8. When a trait is preferentially expressed over another trait, that trait is said to be:
A) Recessive
B) Genotypic
C) Dominant
D) Silent
Answer C: Dominant
Rationale: A dominant allele is expressed in the phenotype whenever it is present, masking the effect of a
recessive allele in heterozygotes.
9. Match the term with its definition: Gamete.
A) The physical manifestation of a trait
B) Sex cells that carry chromosomes
C) The two alleles carried for a given gene
D) The structure on which genes are located
Answer B: Sex cells that carry chromosomes
Rationale: Gametes are the reproductive cells (sperm and egg) that carry chromosomes and unite during
fertilization.
10. Match the term with its definition: Phenotype.
A) The physical manifestation of a trait
B) Sex cells that carry chromosomes
C) Containing two different alleles for a gene
D) The allele that is predominant in a natural population
Answer A: The physical manifestation of a trait
Rationale: Phenotype is the observable expression of a genotype, influenced by both genetic and
environmental factors.
11. Match the term with its definition: Heterozygous.
A) The physical manifestation of a trait
Actual Questions with Verified Answers | Take & Pass the Exam
Questions 1–70+
1. Which of the following statements is correct regarding Mendel's unit factors?
A) Mendel's label of "unit factors" are what we now refer to as chromosomes.
B) Genetic characteristics are controlled by unit factors that exist in pairs.
C) Each gamete carries both unit factors for a trait.
D) Unit factors are always identical to the phenotype.
Answer B: Genetic characteristics are controlled by unit factors that exist in pairs.
Rationale: Mendel's first postulate states that each trait is controlled by "unit factors" (alleles) that occur in
pairs in individual organisms.
2. True or False: A dominant gene will always cause the expression of a dominant phenotype in the
case of complete dominance.
A) True
B) False
Answer A: True
Rationale: Under complete dominance, a single dominant allele is sufficient for the dominant phenotype to
be expressed; the recessive allele's effect is masked in the heterozygote.
3. The defect that causes sickle-cell disease is due to a genetic mutation in which of the following?
A) Ferritin
B) AB glycoprotein
C) β-globulin
D) Sugar molecules on the cell surface
Answer C: β-globulin
Rationale: Sickle-cell disease arises from a single amino-acid substitution (point mutation) in the β-globin
protein of hemoglobin.
,4. A karyotype is a snapshot of the ______ within the cell.
A) DNA; liver; diploid
B) proteins; skin; identical
C) chromosomes; white blood cells; homologous (paired)
D) genes; muscle; single
Answer C: chromosomes; white blood cells; homologous (paired)
Rationale: Karyotyping visualizes chromosomes, typically from metaphase white blood cells, arranged into
homologous pairs to identify structural or numerical chromosomal abnormalities.
5. True or False: A normal chromosome set always has paired X and Y chromosomes.
A) True
B) False
Answer B: False
Rationale: Normal females have XX and normal males have XY; only males possess both X and Y. Thus a
"normal chromosome set" does not always include paired X and Y chromosomes.
6. The phenotype for ______ is distortion of the red blood cells in afflicted people. This results in
depletion of ______ in the blood and poses a significant risk to the patients at ______ altitude.
A) thalassemia; iron; low
B) sickle-cell anemia; oxygen; high
C) malaria; platelets; sea
D) hemophilia; calcium; high
Answer B: sickle-cell anemia; oxygen; high
Rationale: In sickle-cell anemia, deoxygenated hemoglobin S polymerizes, distorting RBCs, lowering oxygen
delivery, and making high altitudes especially dangerous.
7. Two individuals with widow's peaks have a child with a straight hairline. True or False: The gene
for a widow's peak is likely recessive?
A) True
B) False
Answer B: False
, Rationale: Because two parents with widow's peaks produced a straight-hairline child, widow's peak must
be dominant (W) and straight hair recessive (w); both parents are Ww.
8. When a trait is preferentially expressed over another trait, that trait is said to be:
A) Recessive
B) Genotypic
C) Dominant
D) Silent
Answer C: Dominant
Rationale: A dominant allele is expressed in the phenotype whenever it is present, masking the effect of a
recessive allele in heterozygotes.
9. Match the term with its definition: Gamete.
A) The physical manifestation of a trait
B) Sex cells that carry chromosomes
C) The two alleles carried for a given gene
D) The structure on which genes are located
Answer B: Sex cells that carry chromosomes
Rationale: Gametes are the reproductive cells (sperm and egg) that carry chromosomes and unite during
fertilization.
10. Match the term with its definition: Phenotype.
A) The physical manifestation of a trait
B) Sex cells that carry chromosomes
C) Containing two different alleles for a gene
D) The allele that is predominant in a natural population
Answer A: The physical manifestation of a trait
Rationale: Phenotype is the observable expression of a genotype, influenced by both genetic and
environmental factors.
11. Match the term with its definition: Heterozygous.
A) The physical manifestation of a trait
