| Portage Learning
These are original, instructor-style practice questions for study. They are not official
Portage Learning questions and are not copied from any exam, textbook, or question
bank. They are written around common BIOD 101 Module 3 biology topics, especially
DNA, RNA, protein synthesis, genetics, inheritance, mutations, and clinical
genetics.
Question 1:
Which three components make up a DNA nucleotide?
A. Phosphate, deoxyribose sugar, nitrogenous base
B. Phosphate, ribose sugar, amino acid
C. Sulfate, glucose, base
D. Glycerol, fatty acid, base
Correct answer: A
Rationale: A DNA nucleotide contains a phosphate group, deoxyribose sugar, and a
nitrogenous base.
Question 2:
In DNA, adenine pairs with which base?
A. Guanine
B. Cytosine
C. Thymine
D. Uracil
Correct answer: C
Rationale: Adenine pairs with thymine in DNA via two hydrogen bonds.
Question 3:
In RNA, which base replaces thymine?
A. Guanine
B. Uracil
C. Cytosine
D. Adenine
Correct answer: B
Rationale: RNA uses uracil instead of thymine.
,Question 4:
DNA replication is called semiconservative because:
A. One strand is conserved and one is new
B. Both strands are destroyed
C. Only RNA is copied
D. Proteins are copied directly
Correct answer: A
Rationale: Each new DNA molecule has one original strand and one newly synthesized
strand.
Question 5:
Which enzyme unwinds the DNA double helix during replication?
A. Ligase
B. Helicase
C. Primase
D. Polymerase
Correct answer: B
Rationale: Helicase separates the DNA strands by breaking hydrogen bonds.
Question 6:
Which enzyme adds complementary nucleotides during DNA replication?
A. DNA polymerase
B. Helicase
C. Ligase
D. RNA polymerase
Correct answer: A
Rationale: DNA polymerase synthesizes the new DNA strand.
Question 7:
Which enzyme seals nicks between DNA fragments?
A. Primase
B. Ligase
C. Helicase
D. Protease
, Correct answer: B
Rationale: DNA ligase joins Okazaki fragments and seals breaks in DNA.
Question 8:
What is the function of primase?
A. Synthesizes a short RNA primer
B. Unwinds DNA
C. Proofreads proteins
D. Packages proteins
Correct answer: A
Rationale: Primase lays down an RNA primer so DNA polymerase can begin.
Question 9:
Transcription is the process of:
A. Making DNA from DNA
B. Making RNA from DNA
C. Making protein from RNA
D. Making lipid from glucose
Correct answer: B
Rationale: Transcription uses DNA as a template to produce RNA.
Question 10:
Which enzyme carries out transcription?
A. DNA polymerase
B. RNA polymerase
C. Ligase
D. Helicase
Correct answer: B
Rationale: RNA polymerase synthesizes RNA from a DNA template.
Question 11:
Translation occurs at which structure?
A. Nucleus
B. Ribosome
C. Lysosome
D. Golgi apparatus