BIOD 210 / BIOL 210 Module 1 Exam – Genetics (Portage Learning) – 200 Practice Questions with Verified Answers

BIOD 210 / BIOL 210 Module 1 Exam – Genetics (Portage Learning) –
200 Practice Questions with Verified Answers

QUESTIONS 1–200
Topic 1: Foundations and Definitions


1. Which of the following best defines genetics?
A) The study of all living organisms and their classification
B) The study of heredity and the understanding of genes and how they contribute to the passing of traits
C) The study of how organisms interact with their environment
D) The study of the chemical composition of cells
Answer B: The study of heredity and the understanding of genes and how they contribute to the
passing of traits
Rationale: Genetics is formally defined as the study of heredity, focusing on genes and how they contribute
to the passing of traits from one generation to the next.




2. Heredity refers to:
A) The study of cells
B) The transmission of traits from parents to offspring
C) The interaction of organisms with their environment
D) The chemical composition of DNA
Answer B: The transmission of traits from parents to offspring
Rationale: Heredity is the passing of genetic information and traits from parents to offspring.




3. A gene is best defined as:
A) A complete set of genetic information in an organism
B) A segment of DNA that codes for a protein or functional RNA
C) An alternative form of a gene
D) The physical location of a gene on a chromosome
Answer B: A segment of DNA that codes for a protein or functional RNA

,Rationale: A gene is the basic physical and functional unit of heredity—a segment of DNA that codes for a
protein or functional RNA.




4. The genome refers to:
A) A segment of DNA that codes for a protein
B) An alternative form of a gene
C) A complete set of genetic information in an organism
D) The physical location of a gene on a chromosome
Answer C: A complete set of genetic information in an organism
Rationale: The genome is the entire set of genetic material in an organism.




5. An allele is defined as:
A) A segment of DNA that codes for a protein
B) An alternative form of a gene
C) The physical location of a gene on a chromosome
D) The observable traits of an organism
Answer B: An alternative form of a gene
Rationale: Alleles are different versions of the same gene that arise through mutation and occupy the same
locus.




6. The term "genotype" refers to:
A) The observable physical traits of an organism
B) The genetic makeup of an organism (the set of alleles it carries)
C) The interaction between genes and the environment
D) The location of a gene on a chromosome
Answer B: The genetic makeup of an organism (the set of alleles it carries)
Rationale: Genotype is the set of alleles an individual carries; phenotype is the observable expression.




7. The term "phenotype" refers to:
A) The genetic makeup of an organism
B) The observable physical or biochemical traits of an organism
C) The location of a gene on a chromosome

,D) The set of alleles an organism carries
Answer B: The observable physical or biochemical traits of an organism
Rationale: Phenotype is the observable expression of the genotype, influenced by both genetics and
environment.




8. The physical location of a gene on a chromosome is called a(n):
A) Allele
B) Locus
C) Centromere
D) Telomere
Answer B: Locus
Rationale: Locus (plural: loci) refers to the specific physical position of a gene on a chromosome.




9. If an individual has two identical alleles for a trait, they are said to be:
A) Heterozygous
B) Homozygous
C) Hemizygous
D) Nullizygous
Answer B: Homozygous
Rationale: Homozygous means having two identical alleles (e.g., AA or aa); heterozygous means two
different alleles (e.g., Aa).




10. If an individual has two different alleles for a trait, they are said to be:
A) Heterozygous
B) Homozygous
C) Hemizygous
D) Nullizygous
Answer A: Heterozygous
Rationale: Heterozygous means having two different alleles at a locus (e.g., Aa).




11. A dominant allele is expressed when:
A) Only one copy is present

, B) Two copies are present
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C) No copies are present
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D) It is on the X chromosome
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Answer A: Only one copy is present j0 j0 j0 j0 j0 j0




Rationale: A dominant allele masks the expression of a recessive allele in heterozygotes; only one copy is
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12. A recessive allele is expressed only when:
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A) One copy is present
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B) Two copies are present (homozygous recessive)
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C) No copies are present
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D) It is on the Y chromosome
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Answer B: Two copies are present (homozygous recessive)
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Rationale: Recessive alleles are only expressed when the individual is homozygous recessive (aa).
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13. The "wild type" refers to:
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A) The most common phenotype or allele in a natural population
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B) A mutated form of a gene
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C) A dominant allele
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D) A recessive allele
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Answer A: The most common phenotype or allele in a natural population
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Rationale: Wild type is the standard or most common phenotype found in nature.
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14. A "mutant" allele refers to:
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A) The most common form of a gene
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B) A variant allele that has arisen from mutation and may alter phenotype
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C) A dominant allele
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D) A recessive allele
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Answer B: A variant allele that has arisen from mutation and may alter phenotype
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Rationale: Mutant alleles are derived from changes in the DNA sequence. --- ### Topic 2: Historical
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j0 Foundations