MCB2010 midterm review UPDATED ACTUAL Questions and
CORRECT Answers
Question: DNA Subunits
Correct Answer: Nucleotides, each composed of a deoxyribose sugar, a phosphate group, and a
nitrogenous base.
Question: Antiparallel Strands
Correct Answer: The two DNA strands run in opposite directions: one 5' to 3', the other 3' to 5'.
Question: DNA Structure & Inheritance
Correct Answer: Complementary base pairing allows precise replication, preserving genetic information
across generations.
Question: Types of RNA
Correct Answer: mRNA (carries code), tRNA (carries amino acids), and rRNA (forms ribosomes).
Question: tRNA (Transfer RNA)
Correct Answer: The RNA type with hairpin loops that delivers amino acids to the ribosome.
Question: RNA vs. DNA Structure
Correct Answer: RNA is single-stranded, contains ribose, and uses uracil instead of thymine.
Question: Central Dogma
Correct Answer: The flow of genetic information: DNA is transcribed to RNA, which is translated to
protein.
Question: Semiconservative Replication
Correct Answer: Each new DNA molecule consists of one original template strand and one newly
synthesized strand.
Question: Direction of DNA Synthesis
Correct Answer: DNA is always synthesized in the 5' to 3' direction.
Question: DNA Replication Enzymes
Correct Answer: Helicase unwinds DNA; SSBPs stabilize strands; Polymerase synthesizes DNA; Ligase
joins Okazaki fragments.
Question: Bacterial Replication Site
Correct Answer: DNA replication occurs in the cytoplasm of bacterial cells.
Question: Promoter Role
Correct Answer: A DNA sequence where RNA polymerase binds to initiate transcription.
Question: Start Codon (AUG)
Correct Answer: The codon where translation begins, specifying the amino acid methionine.
Question: Codon Function
, Correct Answer: Three-nucleotide mRNA sequences that specify a single amino acid during translation.
Question: Prokaryotic Coupled Transcription/Translation
Correct Answer: Yes, translation can begin before transcription is complete because both occur in the
cytoplasm.
Question: Spontaneous vs. Induced Mutation
Correct Answer: Spontaneous occurs naturally (replication errors); induced is caused by environmental
mutagens.
Question: Types of Mutations
Correct Answer: Silent (no change), missense (different amino acid), nonsense (stop codon), frameshift
(shifted reading frame).
Question: Nonsense Mutation
Correct Answer: A mutation that changes an amino acid codon to a premature stop codon.
Question: Are all mutations harmful?
Correct Answer: No; some are silent (neutral), and others may provide beneficial new traits.
Question: Genotype vs. Phenotype
Correct Answer: Genotype is the genetic makeup; phenotype is the physical expression of those genes.
Question: Genome
Correct Answer: The entire genetic complement of an organism, including all of its genes.
Question: Genetics Terminology
Correct Answer: Genetics is the study of inheritance; genes are the functional units of DNA.
Question: Bacterial Transformation
Correct Answer: The uptake of naked DNA from the environment by a competent cell.
Question: Bacterial Conjugation
Correct Answer: The transfer of DNA between bacteria via direct cell-to-cell contact through a pilus.
Question: Transduction
Correct Answer: The transfer of bacterial DNA from one cell to another mediated by a bacteriophage.
Question: Identifying Mutations
Correct Answer: Compare the mutated DNA sequence to the original using a codon table to see amino
acid changes.
Question: Point Mutation Outcomes
Correct Answer: A single base change can result in silent, missense, or nonsense codons.
Question: Psychrophiles
Correct Answer: Cold-loving microbes that grow best at temperatures around 15°C or lower.
Question: Mesophiles
CORRECT Answers
Question: DNA Subunits
Correct Answer: Nucleotides, each composed of a deoxyribose sugar, a phosphate group, and a
nitrogenous base.
Question: Antiparallel Strands
Correct Answer: The two DNA strands run in opposite directions: one 5' to 3', the other 3' to 5'.
Question: DNA Structure & Inheritance
Correct Answer: Complementary base pairing allows precise replication, preserving genetic information
across generations.
Question: Types of RNA
Correct Answer: mRNA (carries code), tRNA (carries amino acids), and rRNA (forms ribosomes).
Question: tRNA (Transfer RNA)
Correct Answer: The RNA type with hairpin loops that delivers amino acids to the ribosome.
Question: RNA vs. DNA Structure
Correct Answer: RNA is single-stranded, contains ribose, and uses uracil instead of thymine.
Question: Central Dogma
Correct Answer: The flow of genetic information: DNA is transcribed to RNA, which is translated to
protein.
Question: Semiconservative Replication
Correct Answer: Each new DNA molecule consists of one original template strand and one newly
synthesized strand.
Question: Direction of DNA Synthesis
Correct Answer: DNA is always synthesized in the 5' to 3' direction.
Question: DNA Replication Enzymes
Correct Answer: Helicase unwinds DNA; SSBPs stabilize strands; Polymerase synthesizes DNA; Ligase
joins Okazaki fragments.
Question: Bacterial Replication Site
Correct Answer: DNA replication occurs in the cytoplasm of bacterial cells.
Question: Promoter Role
Correct Answer: A DNA sequence where RNA polymerase binds to initiate transcription.
Question: Start Codon (AUG)
Correct Answer: The codon where translation begins, specifying the amino acid methionine.
Question: Codon Function
, Correct Answer: Three-nucleotide mRNA sequences that specify a single amino acid during translation.
Question: Prokaryotic Coupled Transcription/Translation
Correct Answer: Yes, translation can begin before transcription is complete because both occur in the
cytoplasm.
Question: Spontaneous vs. Induced Mutation
Correct Answer: Spontaneous occurs naturally (replication errors); induced is caused by environmental
mutagens.
Question: Types of Mutations
Correct Answer: Silent (no change), missense (different amino acid), nonsense (stop codon), frameshift
(shifted reading frame).
Question: Nonsense Mutation
Correct Answer: A mutation that changes an amino acid codon to a premature stop codon.
Question: Are all mutations harmful?
Correct Answer: No; some are silent (neutral), and others may provide beneficial new traits.
Question: Genotype vs. Phenotype
Correct Answer: Genotype is the genetic makeup; phenotype is the physical expression of those genes.
Question: Genome
Correct Answer: The entire genetic complement of an organism, including all of its genes.
Question: Genetics Terminology
Correct Answer: Genetics is the study of inheritance; genes are the functional units of DNA.
Question: Bacterial Transformation
Correct Answer: The uptake of naked DNA from the environment by a competent cell.
Question: Bacterial Conjugation
Correct Answer: The transfer of DNA between bacteria via direct cell-to-cell contact through a pilus.
Question: Transduction
Correct Answer: The transfer of bacterial DNA from one cell to another mediated by a bacteriophage.
Question: Identifying Mutations
Correct Answer: Compare the mutated DNA sequence to the original using a codon table to see amino
acid changes.
Question: Point Mutation Outcomes
Correct Answer: A single base change can result in silent, missense, or nonsense codons.
Question: Psychrophiles
Correct Answer: Cold-loving microbes that grow best at temperatures around 15°C or lower.
Question: Mesophiles
