BIOD 210 Exam 2 – Genetics Portage Learning – (2026) Actual Questions &
Answers
Module 1: Foundations of Genetics
1. The chromosomal theory of inheritance states that:
A) Chromosomes are contained within genes that encode for all genetic traits
B) Chromosomes inherited from a father will be dominant over those from the
mother
C) The proteins within chromosomes are the main drivers of genetic inheritance
D) Genes, contributed from each parent, are carried on chromosomes
Answer: D
Rationale: The chromosomal theory links Mendel's "factors" to physical
structures—chromosomes—that segregate and assort during meiosis. This
explains how genes are transmitted from parents to offspring .
2. Nucleotides are the basic building blocks that make up DNA.
A) True
B) False
C) Only in prokaryotes
D) Only in eukaryotes
,Answer: A
Rationale: DNA is a polymer of nucleotides, each consisting of a sugar, phosphate,
and nitrogenous base. The sequence of nucleotides encodes genetic information,
making them correctly described as the "building blocks" of DNA .
3. How does preformation differ from epigenesis?
A) Preformation says development builds structures stepwise; epigenesis says a
tiny preformed human just grows
B) Preformation says a tiny fully formed human exists in the gamete and only
grows; epigenesis says structures arise gradually from an initially simple embryo
C) Both theories state that environment alone shapes the embryo
D) They are the same concept with different names
Answer: B
Rationale: Historically, preformationists imagined a homunculus inside the
gamete that simply enlarged. Epigenesis correctly states that tissues and organs
form progressively through cell division and differentiation, matching modern
developmental biology .
,4. Match each word with its correct definition: Diploid number, Phenotype,
Genotype, Alleles, Gene, Chromosome.
A) Diploid number – number of chromosomes; Phenotype – observable traits;
Genotype – allele combination; Alleles – alternative forms of a gene; Gene – unit
of heredity; Chromosome – DNA-containing structure that exists in pairs
B) Diploid number – number of genes; Phenotype – DNA sequence; Genotype –
physical appearance; Alleles – chromosomes; Gene – protein; Chromosome – RNA
C) Diploid number – number of proteins; Phenotype – genotype; Genotype –
environment; Alleles – mutations only; Gene – chromosome; Chromosome – cell
D) Diploid number – number of cells; Phenotype – number of alleles; Genotype –
population size; Alleles – phenotypes; Gene – RNA; Chromosome – organelle
Answer: A
Rationale: These definitions align with core genetics terminology. Understanding
the relationship between genes, alleles, genotype, and phenotype—and their
packaging into chromosomes—is foundational for interpreting patterns of
inheritance .
5. What type of plants did Gregor Mendel use in his famous experiments?
A) Corn plants
B) Pea plants
, C) Tomato plants
D) Wheat plants
Answer: B
Rationale: Mendel chose garden peas because they have easily observable traits,
short generation times, and can self-pollinate or be cross-pollinated. This allowed
him to derive the basic laws of inheritance .
6. Charles Darwin's publication on evolution is called:
A) Evolution in a Modern Age
B) The Origin of Species
C) The Theory of Relativity
D) Principles of Genetics
Answer: B
Rationale: Darwin's 1859 book "On the Origin of Species" introduced the theory of
evolution by natural selection, fundamentally changing biological thought .
7. How many total chromosomes are in a normal human chromosome set?
Chromosomes exist in matched numbers of ____.
Answers
Module 1: Foundations of Genetics
1. The chromosomal theory of inheritance states that:
A) Chromosomes are contained within genes that encode for all genetic traits
B) Chromosomes inherited from a father will be dominant over those from the
mother
C) The proteins within chromosomes are the main drivers of genetic inheritance
D) Genes, contributed from each parent, are carried on chromosomes
Answer: D
Rationale: The chromosomal theory links Mendel's "factors" to physical
structures—chromosomes—that segregate and assort during meiosis. This
explains how genes are transmitted from parents to offspring .
2. Nucleotides are the basic building blocks that make up DNA.
A) True
B) False
C) Only in prokaryotes
D) Only in eukaryotes
,Answer: A
Rationale: DNA is a polymer of nucleotides, each consisting of a sugar, phosphate,
and nitrogenous base. The sequence of nucleotides encodes genetic information,
making them correctly described as the "building blocks" of DNA .
3. How does preformation differ from epigenesis?
A) Preformation says development builds structures stepwise; epigenesis says a
tiny preformed human just grows
B) Preformation says a tiny fully formed human exists in the gamete and only
grows; epigenesis says structures arise gradually from an initially simple embryo
C) Both theories state that environment alone shapes the embryo
D) They are the same concept with different names
Answer: B
Rationale: Historically, preformationists imagined a homunculus inside the
gamete that simply enlarged. Epigenesis correctly states that tissues and organs
form progressively through cell division and differentiation, matching modern
developmental biology .
,4. Match each word with its correct definition: Diploid number, Phenotype,
Genotype, Alleles, Gene, Chromosome.
A) Diploid number – number of chromosomes; Phenotype – observable traits;
Genotype – allele combination; Alleles – alternative forms of a gene; Gene – unit
of heredity; Chromosome – DNA-containing structure that exists in pairs
B) Diploid number – number of genes; Phenotype – DNA sequence; Genotype –
physical appearance; Alleles – chromosomes; Gene – protein; Chromosome – RNA
C) Diploid number – number of proteins; Phenotype – genotype; Genotype –
environment; Alleles – mutations only; Gene – chromosome; Chromosome – cell
D) Diploid number – number of cells; Phenotype – number of alleles; Genotype –
population size; Alleles – phenotypes; Gene – RNA; Chromosome – organelle
Answer: A
Rationale: These definitions align with core genetics terminology. Understanding
the relationship between genes, alleles, genotype, and phenotype—and their
packaging into chromosomes—is foundational for interpreting patterns of
inheritance .
5. What type of plants did Gregor Mendel use in his famous experiments?
A) Corn plants
B) Pea plants
, C) Tomato plants
D) Wheat plants
Answer: B
Rationale: Mendel chose garden peas because they have easily observable traits,
short generation times, and can self-pollinate or be cross-pollinated. This allowed
him to derive the basic laws of inheritance .
6. Charles Darwin's publication on evolution is called:
A) Evolution in a Modern Age
B) The Origin of Species
C) The Theory of Relativity
D) Principles of Genetics
Answer: B
Rationale: Darwin's 1859 book "On the Origin of Species" introduced the theory of
evolution by natural selection, fundamentally changing biological thought .
7. How many total chromosomes are in a normal human chromosome set?
Chromosomes exist in matched numbers of ____.
