BIOD 210 GENETICS Exam MODULE 5 Questions and Ansẉers update

BIOD 210 GENETICS
Exam MODULE 5 Questions and
Ansẉers
2026\2027 update

1. Q: What did Frederick Griffith’s experiment with mice and
Streptococcus pneumoniae demonstrate?
ANSWER The process of transformation, proving that genetic
material could be transferred between bacteria.


2. Q: What was the conclusion of Avery, MacLeod, and McCarty’s
experiment?
ANSWER That DNA is the transforming principle (the genetic
material), not protein or RNA.


3. Q: How did the Hershey-Chase experiment prove DNA was the
genetic material?
ANSWER By using radioactive isotopes (32P for DNA, 35S for protein)
to show that only the DNA of the bacteriophage entered the bacteria
to direct viral replication.


4. Q: Who discovered the double-helix structure of DNA?
ANSWER James Watson and Francis Crick, using Rosalind Franklin's
X-ray diffraction data.


5. Q: What is Chargaff’s first rule?

, ANSWER The amount of adenine (A) equals the amount of thymine
(T), and the amount of guanine (G) equals the amount of cytosine
(C).


6. Q: What is Chargaff’s second rule?
ANSWER The ratio of (A+T) to (G+C) varies from species to species
but is constant within a species.


7. Q: What are the four nitrogenous bases found in DNA?
ANSWER Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).


8. Q: Which bases are purines?
ANSWER Adenine and Guanine (two-ring structures).


9. Q: Which bases are pyrimidines?
ANSWER Cytosine and Thymine (single-ring structures).


10. Q: What replaces Thymine in RNA?
ANSWER Uracil (U).


11. Q: What type of bond holds the two strands of DNA together?
ANSWER Hydrogen bonds (two between A and T, three between G
and C).


12. Q: What is the sugar found in DNA?
ANSWER Deoxyribose.