RIO BIO 202 EXAM 2 STUDY GUIDE 2026 –
COMPLETE CONCEPT REVIEW & PRACTICE
MATERIALS (LATEST EDITION)
Genetics & Molecular Biology (Questions 1-30)
1. What is the primary function of DNA polymerase during replication?
a) Unwinding the DNA double helix
b) Adding RNA nucleotides to form a primer
c) Adding DNA nucleotides to the 3' end of a growing strand ✓
d) Joining Okazaki fragments on the lagging strand
2. Which of the following best describes a codon?
a) A sequence of three nucleotides on tRNA that pairs with mRNA
b) A sequence of three nucleotides on mRNA that specifies an amino acid ✓
c) The enzyme that catalyzes the formation of peptide bonds
d) A non-coding sequence removed during RNA splicing
3. In a diploid organism, a heterozygous genotype means:
a) Both alleles for a gene are identical
b) The two alleles for a gene are different ✓
c) The gene is located on the X chromosome
d) The individual displays the recessive phenotype
4. A cross between two heterozygous (Aa) individuals is expected to yield what
phenotypic ratio?
a) 1:1
b) 3:1 ✓
c) 9:3:3:1
d) 1:2:1
5. Which process increases genetic variation within a population?
a) Mitosis
b) Asexual reproduction
c) Crossing over during meiosis ✓
d) Self-fertilization in plants
6. The Central Dogma of molecular biology describes the flow of information as:
a) Protein → RNA → DNA
, b) DNA → RNA → Protein ✓
c) RNA → DNA → Protein
d) DNA → Protein → RNA
7. What is the role of messenger RNA (mRNA)?
a) Carries amino acids to the ribosome
b) Forms the core structure of the ribosome
c) Serves as a template for protein synthesis ✓
d) Catalyzes the process of transcription
8. Which of the following mutations would most likely be frameshift mutation?
a) Substitution of one nucleotide for another
b) Insertion of three nucleotides
c) Deletion of one nucleotide ✓
d) Inversion of a chromosome segment
9. In a DNA molecule, adenine (A) always pairs with:
a) Cytosine (C)
b) Guanine (G)
c) Thymine (T) ✓
d) Uracil (U)
10. Which phase of the cell cycle does DNA replication occur?
a) G1
b) S ✓
c) G2
d) M
11. What is the function of a promoter in transcription?
a) It is the binding site for RNA polymerase ✓
b) It codes for the first amino acid
c) It terminates the RNA strand
d) It is part of the ribosome
12. A human somatic cell contains how many chromosomes?
a) 23
b) 46 ✓
c) 22
d) 92
,13. The process by which the genetic code in mRNA is used to assemble a protein is called:
a) Replication
b) Transcription
c) Translation ✓
d) Translocation
14. Which type of RNA carries an anticodon?
a) mRNA
b) rRNA
c) tRNA ✓
d) snRNA
15. The observable physical or biochemical characteristics of an organism are its:
a) Genotype
b) Phenotype ✓
c) Karyotype
d) Allele
16. In a monohybrid cross, the F2 generation phenotypic ratio is 3:1. This demonstrates:
a) Incomplete dominance
b) Codominance
c) Independent assortment
d) Mendelian dominance/recessiveness ✓
17. A test cross is used to determine:
a) The number of alleles for a trait
b) Whether an individual with a dominant phenotype is homozygous or heterozygous ✓
c) The mutation rate of a gene
d) The linkage between two genes
18. Which of the following is true about sex-linked traits?
a) They are only found on the Y chromosome.
b) They are more commonly expressed in females.
c) They are genes located on the sex chromosomes. ✓
d) They always affect reproductive organs.
19. What is polygenic inheritance?
a) A single gene affecting multiple traits
b) Multiple genes influencing a single trait ✓
, c) Genes that are only active in polyps
d) Inheritance of extra chromosomes
20. A Barr body is an example of:
a) Genomic imprinting
b) X-chromosome inactivation ✓
c) A mitochondrial defect
d) A recessive allele on the Y chromosome
21. In DNA replication, the lagging strand is synthesized:
a) Continuously toward the replication fork
b) Discontinuously as Okazaki fragments ✓
c) By DNA polymerase I only
d) In the 3' to 5' direction
22. Which enzyme is responsible for "unzipping" the DNA double helix?
a) DNA polymerase
b) Primase
c) Ligase
d) Helicase ✓
23. What is the source of energy for translation elongation?
a) ATP
b) GTP ✓
c) TTP
d) NADH
24. A silent mutation is one that:
a) Changes a codon to a stop codon
b) Alters the amino acid sequence of the protein
c) Changes a nucleotide but not the amino acid specified ✓
d) Inserts a large section of DNA
25. Sickle cell anemia is an example of which type of mutation effect?
a) Silent
b) Missense ✓
c) Nonsense
d) Frameshift
26. The operon model of gene regulation was first described in:
a) Homo sapiens (humans)
COMPLETE CONCEPT REVIEW & PRACTICE
MATERIALS (LATEST EDITION)
Genetics & Molecular Biology (Questions 1-30)
1. What is the primary function of DNA polymerase during replication?
a) Unwinding the DNA double helix
b) Adding RNA nucleotides to form a primer
c) Adding DNA nucleotides to the 3' end of a growing strand ✓
d) Joining Okazaki fragments on the lagging strand
2. Which of the following best describes a codon?
a) A sequence of three nucleotides on tRNA that pairs with mRNA
b) A sequence of three nucleotides on mRNA that specifies an amino acid ✓
c) The enzyme that catalyzes the formation of peptide bonds
d) A non-coding sequence removed during RNA splicing
3. In a diploid organism, a heterozygous genotype means:
a) Both alleles for a gene are identical
b) The two alleles for a gene are different ✓
c) The gene is located on the X chromosome
d) The individual displays the recessive phenotype
4. A cross between two heterozygous (Aa) individuals is expected to yield what
phenotypic ratio?
a) 1:1
b) 3:1 ✓
c) 9:3:3:1
d) 1:2:1
5. Which process increases genetic variation within a population?
a) Mitosis
b) Asexual reproduction
c) Crossing over during meiosis ✓
d) Self-fertilization in plants
6. The Central Dogma of molecular biology describes the flow of information as:
a) Protein → RNA → DNA
, b) DNA → RNA → Protein ✓
c) RNA → DNA → Protein
d) DNA → Protein → RNA
7. What is the role of messenger RNA (mRNA)?
a) Carries amino acids to the ribosome
b) Forms the core structure of the ribosome
c) Serves as a template for protein synthesis ✓
d) Catalyzes the process of transcription
8. Which of the following mutations would most likely be frameshift mutation?
a) Substitution of one nucleotide for another
b) Insertion of three nucleotides
c) Deletion of one nucleotide ✓
d) Inversion of a chromosome segment
9. In a DNA molecule, adenine (A) always pairs with:
a) Cytosine (C)
b) Guanine (G)
c) Thymine (T) ✓
d) Uracil (U)
10. Which phase of the cell cycle does DNA replication occur?
a) G1
b) S ✓
c) G2
d) M
11. What is the function of a promoter in transcription?
a) It is the binding site for RNA polymerase ✓
b) It codes for the first amino acid
c) It terminates the RNA strand
d) It is part of the ribosome
12. A human somatic cell contains how many chromosomes?
a) 23
b) 46 ✓
c) 22
d) 92
,13. The process by which the genetic code in mRNA is used to assemble a protein is called:
a) Replication
b) Transcription
c) Translation ✓
d) Translocation
14. Which type of RNA carries an anticodon?
a) mRNA
b) rRNA
c) tRNA ✓
d) snRNA
15. The observable physical or biochemical characteristics of an organism are its:
a) Genotype
b) Phenotype ✓
c) Karyotype
d) Allele
16. In a monohybrid cross, the F2 generation phenotypic ratio is 3:1. This demonstrates:
a) Incomplete dominance
b) Codominance
c) Independent assortment
d) Mendelian dominance/recessiveness ✓
17. A test cross is used to determine:
a) The number of alleles for a trait
b) Whether an individual with a dominant phenotype is homozygous or heterozygous ✓
c) The mutation rate of a gene
d) The linkage between two genes
18. Which of the following is true about sex-linked traits?
a) They are only found on the Y chromosome.
b) They are more commonly expressed in females.
c) They are genes located on the sex chromosomes. ✓
d) They always affect reproductive organs.
19. What is polygenic inheritance?
a) A single gene affecting multiple traits
b) Multiple genes influencing a single trait ✓
, c) Genes that are only active in polyps
d) Inheritance of extra chromosomes
20. A Barr body is an example of:
a) Genomic imprinting
b) X-chromosome inactivation ✓
c) A mitochondrial defect
d) A recessive allele on the Y chromosome
21. In DNA replication, the lagging strand is synthesized:
a) Continuously toward the replication fork
b) Discontinuously as Okazaki fragments ✓
c) By DNA polymerase I only
d) In the 3' to 5' direction
22. Which enzyme is responsible for "unzipping" the DNA double helix?
a) DNA polymerase
b) Primase
c) Ligase
d) Helicase ✓
23. What is the source of energy for translation elongation?
a) ATP
b) GTP ✓
c) TTP
d) NADH
24. A silent mutation is one that:
a) Changes a codon to a stop codon
b) Alters the amino acid sequence of the protein
c) Changes a nucleotide but not the amino acid specified ✓
d) Inserts a large section of DNA
25. Sickle cell anemia is an example of which type of mutation effect?
a) Silent
b) Missense ✓
c) Nonsense
d) Frameshift
26. The operon model of gene regulation was first described in:
a) Homo sapiens (humans)
