BIOD210 Module 3 Genetics Exam | Portage
Learning | Complete Study Guide with
Verified Questions & Answers | Genetics
Concepts, Problem Solving & Exam Prep
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BIOD210 MODULE 3 GENETICS EXAM
Portage Learning Complete Study Guide with Verified Questions & Answers
DOCUMENT OVERVIEW
• This comprehensive 200-question study guide is designed to reinforce mastery of
all genetics concepts, problem-solving techniques, and exam competencies
required for BIOD210 Module 3, with detailed EXPERT RATIONALE for each
question to support deep understanding and retention.
• Study this material by working through questions sequentially, reviewing EXPERT
RATIONALE carefully for both correct and incorrect options, and using patterns to
strengthen your conceptual foundation before attempting the actual proctored
exam.
1. What is the basic unit of heredity responsible for transmitting traits from
parents to offspring?
A) Chromosome
B) Gene
C) Protein
D) Enzyme
E) Lipid
✓ CORRECT ANSWER: B) Gene
EXPERT RATIONALE: A gene is the fundamental unit of heredity composed of DNA
sequences that code for specific traits. Chromosomes are structures containing
,many genes; proteins and enzymes are gene products; lipids are not involved in
heredity transmission. Genes encode the instructions for all inherited
characteristics.
2. Which statement best describes the relationship between genotype and
phenotype?
A) Genotype and phenotype are identical in all organisms
B) Genotype is the genetic makeup; phenotype is the observable physical
expression of genes
C) Phenotype determines genotype in all cases
D) Genotype only affects internal organs, not external appearance
E) Phenotype is inherited directly from grandparents only
✓ CORRECT ANSWER: B) Genotype is the genetic makeup; phenotype is the
observable physical expression of genes
EXPERT RATIONALE: Genotype refers to the alleles an organism possesses;
phenotype is what we observe (traits, characteristics). These are distinct—two
organisms with the same phenotype may have different genotypes (e.g., dominant
homozygous vs. heterozygous). Environmental factors also influence phenotype
expression.
3. In a monohybrid cross between two heterozygous tall pea plants (Tt), what
is the expected phenotypic ratio of offspring?
A) 1:1
B) 3:1
C) 1:2:1
D) 9:3:3:1
E) 1:1:1:1
,✓ CORRECT ANSWER: B) 3:1
EXPERT RATIONALE: In Tt × Tt cross, offspring are: 1 TT (tall), 2 Tt (tall), 1 tt (short).
The ratio is 3 tall : 1 short. The 1:2:1 ratio refers to genotypes, not phenotypes. This
demonstrates segregation of alleles and dominance of the tall allele.
4. What is the term for alternate forms of a gene at the same locus?
A) Genotypes
B) Gametes
C) Alleles
D) Mutations
E) Chromosomes
✓ CORRECT ANSWER: C) Alleles
EXPERT RATIONALE: Alleles are different forms of a gene (e.g., T for tall, t for short
in peas). Genotypes are combinations of alleles; gametes are reproductive cells;
mutations are changes in DNA; chromosomes contain genes. Alleles represent
genetic variation at specific loci.
5. Which of Mendel's laws states that allele pairs separate during gamete
formation?
A) Law of Segregation
B) Law of Independent Assortment
C) Law of Dominance
D) Law of Recessiveness
E) Law of Mutation
✓ CORRECT ANSWER: A) Law of Segregation
, EXPERT RATIONALE: The Law of Segregation describes how pairs of alleles
separate during meiosis, ensuring each gamete receives only one allele per gene.
This explains why heterozygotes produce two types of gametes in equal
proportions. It is the fundamental principle of heredity.
6. A homozygous recessive individual has the genotype:
A) AA
B) Aa
C) aa
D) A_
E) Aa or aa
✓ CORRECT ANSWER: C) aa
EXPERT RATIONALE: Homozygous recessive means both alleles are the same
recessive allele (lowercase). AA is homozygous dominant; Aa is heterozygous; A_
indicates at least one dominant allele. Homozygous recessive organisms always
express the recessive phenotype.
7. In humans, the ABO blood group is determined by:
A) A single gene with two alleles
B) A single gene with three alleles
C) Three genes with one allele each
D) Three genes with two alleles each
E) Environmental factors only
✓ CORRECT ANSWER: B) A single gene with three alleles
EXPERT RATIONALE: The ABO blood type is controlled by one gene (I) with three
possible alleles: I^A, I^B, and i. This is multiple alleles inheritance, where more than
Learning | Complete Study Guide with
Verified Questions & Answers | Genetics
Concepts, Problem Solving & Exam Prep
BIOD210 MODULE 3 GENETICS EXAM
Portage Learning Complete Study Guide with Verified Questions & Answers
DOCUMENT OVERVIEW
• This comprehensive 200-question study guide is designed to reinforce mastery of
all genetics concepts, problem-solving techniques, and exam competencies
required for BIOD210 Module 3, with detailed EXPERT RATIONALE for each
question to support deep understanding and retention.
• Study this material by working through questions sequentially, reviewing EXPERT
RATIONALE carefully for both correct and incorrect options, and using patterns to
strengthen your conceptual foundation before attempting the actual proctored
exam.
1. What is the basic unit of heredity responsible for transmitting traits from
parents to offspring?
A) Chromosome
B) Gene
C) Protein
D) Enzyme
E) Lipid
✓ CORRECT ANSWER: B) Gene
EXPERT RATIONALE: A gene is the fundamental unit of heredity composed of DNA
sequences that code for specific traits. Chromosomes are structures containing
,many genes; proteins and enzymes are gene products; lipids are not involved in
heredity transmission. Genes encode the instructions for all inherited
characteristics.
2. Which statement best describes the relationship between genotype and
phenotype?
A) Genotype and phenotype are identical in all organisms
B) Genotype is the genetic makeup; phenotype is the observable physical
expression of genes
C) Phenotype determines genotype in all cases
D) Genotype only affects internal organs, not external appearance
E) Phenotype is inherited directly from grandparents only
✓ CORRECT ANSWER: B) Genotype is the genetic makeup; phenotype is the
observable physical expression of genes
EXPERT RATIONALE: Genotype refers to the alleles an organism possesses;
phenotype is what we observe (traits, characteristics). These are distinct—two
organisms with the same phenotype may have different genotypes (e.g., dominant
homozygous vs. heterozygous). Environmental factors also influence phenotype
expression.
3. In a monohybrid cross between two heterozygous tall pea plants (Tt), what
is the expected phenotypic ratio of offspring?
A) 1:1
B) 3:1
C) 1:2:1
D) 9:3:3:1
E) 1:1:1:1
,✓ CORRECT ANSWER: B) 3:1
EXPERT RATIONALE: In Tt × Tt cross, offspring are: 1 TT (tall), 2 Tt (tall), 1 tt (short).
The ratio is 3 tall : 1 short. The 1:2:1 ratio refers to genotypes, not phenotypes. This
demonstrates segregation of alleles and dominance of the tall allele.
4. What is the term for alternate forms of a gene at the same locus?
A) Genotypes
B) Gametes
C) Alleles
D) Mutations
E) Chromosomes
✓ CORRECT ANSWER: C) Alleles
EXPERT RATIONALE: Alleles are different forms of a gene (e.g., T for tall, t for short
in peas). Genotypes are combinations of alleles; gametes are reproductive cells;
mutations are changes in DNA; chromosomes contain genes. Alleles represent
genetic variation at specific loci.
5. Which of Mendel's laws states that allele pairs separate during gamete
formation?
A) Law of Segregation
B) Law of Independent Assortment
C) Law of Dominance
D) Law of Recessiveness
E) Law of Mutation
✓ CORRECT ANSWER: A) Law of Segregation
, EXPERT RATIONALE: The Law of Segregation describes how pairs of alleles
separate during meiosis, ensuring each gamete receives only one allele per gene.
This explains why heterozygotes produce two types of gametes in equal
proportions. It is the fundamental principle of heredity.
6. A homozygous recessive individual has the genotype:
A) AA
B) Aa
C) aa
D) A_
E) Aa or aa
✓ CORRECT ANSWER: C) aa
EXPERT RATIONALE: Homozygous recessive means both alleles are the same
recessive allele (lowercase). AA is homozygous dominant; Aa is heterozygous; A_
indicates at least one dominant allele. Homozygous recessive organisms always
express the recessive phenotype.
7. In humans, the ABO blood group is determined by:
A) A single gene with two alleles
B) A single gene with three alleles
C) Three genes with one allele each
D) Three genes with two alleles each
E) Environmental factors only
✓ CORRECT ANSWER: B) A single gene with three alleles
EXPERT RATIONALE: The ABO blood type is controlled by one gene (I) with three
possible alleles: I^A, I^B, and i. This is multiple alleles inheritance, where more than
