BIOLOGY 340 FINAL EXAM NEWEST 2026 ACTUAL
EXAM| BIOLOGY 340 FINAL EXAM REVIEW WITH
COMPLETE REAL EXAM QUESTIONS AND CORRECT
VERIFIED ANSWERS/ ALREADY GRADED A+
1. What type of bonds are formed between complementary
DNA bases?
A) Covalent bonds
B) Ionic bonds
C) Hydrogen bonds
D) Peptide bonds
Answer: C
Rationale: Complementary DNA bases (A-T and G-C) are held
together by hydrogen bonds. Adenine forms two hydrogen bonds
with thymine, while guanine forms three hydrogen bonds with
cytosine .
1
,2. Which of the following forms the backbone of a
polynucleotide chain?
A) Nitrogenous bases
B) Alternating sugar and phosphate groups
C) Hydrogen bonds
D) Amino acids
Answer: B
Rationale: The DNA backbone consists of alternating deoxyribose
sugar and phosphate groups connected by phosphodiester bonds.
The nitrogenous bases project inward from this backbone .
3. Guanine and adenine are purines found in DNA.
A) True
B) False
Answer: A
Rationale: Guanine and adenine are both purine bases (double-ring
2
,structures) found in DNA. Cytosine and thymine are pyrimidines
(single-ring structures) .
4. What fraction of the nucleotides in a double-stranded DNA
molecule are cytosine and thymine?
A) 25%
B) 50%
C) 75%
D) 100%
Answer: B
Rationale: In double-stranded DNA, purines (A+G) equal
pyrimidines (C+T) due to Chargaff's rules. Therefore, C+T
together make up 50% of the nucleotides .
5. What is one difference between DNA replication in bacteria
versus eukaryotes?
A) Bacteria use RNA primers; eukaryotes do not
3
, B) Eukaryotic chromosomes have many origins of replication,
while bacteria have only one
C) Bacteria replicate DNA in the 3' to 5' direction
D) Eukaryotes do not use DNA polymerase
Answer: B
Rationale: Eukaryotic chromosomes are large and linear, requiring
multiple origins of replication to complete replication in a timely
manner. Bacterial chromosomes are circular and smaller, typically
having a single origin of replication .
6. What is the maximum rate of DNA replication in E. coli?
A) 100 nucleotides per second
B) 1000 nucleotides per second
C) 10,000 nucleotides per second
D) 100,000 nucleotides per second
4
EXAM| BIOLOGY 340 FINAL EXAM REVIEW WITH
COMPLETE REAL EXAM QUESTIONS AND CORRECT
VERIFIED ANSWERS/ ALREADY GRADED A+
1. What type of bonds are formed between complementary
DNA bases?
A) Covalent bonds
B) Ionic bonds
C) Hydrogen bonds
D) Peptide bonds
Answer: C
Rationale: Complementary DNA bases (A-T and G-C) are held
together by hydrogen bonds. Adenine forms two hydrogen bonds
with thymine, while guanine forms three hydrogen bonds with
cytosine .
1
,2. Which of the following forms the backbone of a
polynucleotide chain?
A) Nitrogenous bases
B) Alternating sugar and phosphate groups
C) Hydrogen bonds
D) Amino acids
Answer: B
Rationale: The DNA backbone consists of alternating deoxyribose
sugar and phosphate groups connected by phosphodiester bonds.
The nitrogenous bases project inward from this backbone .
3. Guanine and adenine are purines found in DNA.
A) True
B) False
Answer: A
Rationale: Guanine and adenine are both purine bases (double-ring
2
,structures) found in DNA. Cytosine and thymine are pyrimidines
(single-ring structures) .
4. What fraction of the nucleotides in a double-stranded DNA
molecule are cytosine and thymine?
A) 25%
B) 50%
C) 75%
D) 100%
Answer: B
Rationale: In double-stranded DNA, purines (A+G) equal
pyrimidines (C+T) due to Chargaff's rules. Therefore, C+T
together make up 50% of the nucleotides .
5. What is one difference between DNA replication in bacteria
versus eukaryotes?
A) Bacteria use RNA primers; eukaryotes do not
3
, B) Eukaryotic chromosomes have many origins of replication,
while bacteria have only one
C) Bacteria replicate DNA in the 3' to 5' direction
D) Eukaryotes do not use DNA polymerase
Answer: B
Rationale: Eukaryotic chromosomes are large and linear, requiring
multiple origins of replication to complete replication in a timely
manner. Bacterial chromosomes are circular and smaller, typically
having a single origin of replication .
6. What is the maximum rate of DNA replication in E. coli?
A) 100 nucleotides per second
B) 1000 nucleotides per second
C) 10,000 nucleotides per second
D) 100,000 nucleotides per second
4
