BIMM 100 Midterm 1 Review Questions With Complete
Solutions
Avery, Mcleod, McCarthy: They continued Griffith's studies but
what did they do differently? Correct Answers They monitored
transformation on plates rather than in mice.
Avery, Mcleod, McCarthy: What did smooth colonies of
bacteria on the plates indicate? Correct Answers Something in
the fraction has the transforming substance.
Avery, Mcleod, McCarthy: What did they discover? Correct
Answers The genetic material is DNA. However, people were
still not convinced.
Avery, Mcleod, McCarthy: What was the procedure of their
experiment? Correct Answers 1. Broke down the heat-killed
smooth strain of pneumacocous and mixed different fractions of
live rough pneumacocous.
2. directly cultured the pneumacocous fractions onto a plate
3. Looked for colonies with smooth surfaces [smooth
phenotype].
Base Excision Repair sequence: Correct Answers 1. Remove
incorrect base
2. & 3. Endonucleases [DNA glycosylase and APEI
endonuclease] removes deoxyribose phosphate
4. Gap is filled with correct base by DNA polymerase and DNA
ligase.
, Base Excision Repair: What type/cause of damage is needed for
base-excision repair to occur? Correct Answers A base is
chemically changed [ex. C turns into a T]
Chargaff's studies showed that in DNA, [A] = [T] and [G] = [C].
Similar studies from the Spirin lab showed no such rule in RNA:
[A], [U], [G], and [C] were all different. What is the
explanation?
A. RNA has different bases than DNA.
B. RNA has a different sequence than DNA.
C. RNA is generally single-stranded.
D. Base pairs cannot form in RNA.
E. RNA is not capable of forming a double helix. Correct
Answers C. RNA is generally single-stranded.
Conservative model of DNA replication: Correct Answers The
parent DNA replicates itself. New DNA does not contain any
strands from parent DNA.
Double-stranded break is caused by what? Correct Answers
Ionizing radiation (X rays or gamma radiation) or anti-tumor
drugs
Double-stranded break: Why is end-joining "error-prone"?
Correct Answers 1. Recognition of broken ends
2. Exonucleases remove overhang nucleotides***
3. Ligation
This end joining creates errors; a lot of genetic information is
gone permanently.
Solutions
Avery, Mcleod, McCarthy: They continued Griffith's studies but
what did they do differently? Correct Answers They monitored
transformation on plates rather than in mice.
Avery, Mcleod, McCarthy: What did smooth colonies of
bacteria on the plates indicate? Correct Answers Something in
the fraction has the transforming substance.
Avery, Mcleod, McCarthy: What did they discover? Correct
Answers The genetic material is DNA. However, people were
still not convinced.
Avery, Mcleod, McCarthy: What was the procedure of their
experiment? Correct Answers 1. Broke down the heat-killed
smooth strain of pneumacocous and mixed different fractions of
live rough pneumacocous.
2. directly cultured the pneumacocous fractions onto a plate
3. Looked for colonies with smooth surfaces [smooth
phenotype].
Base Excision Repair sequence: Correct Answers 1. Remove
incorrect base
2. & 3. Endonucleases [DNA glycosylase and APEI
endonuclease] removes deoxyribose phosphate
4. Gap is filled with correct base by DNA polymerase and DNA
ligase.
, Base Excision Repair: What type/cause of damage is needed for
base-excision repair to occur? Correct Answers A base is
chemically changed [ex. C turns into a T]
Chargaff's studies showed that in DNA, [A] = [T] and [G] = [C].
Similar studies from the Spirin lab showed no such rule in RNA:
[A], [U], [G], and [C] were all different. What is the
explanation?
A. RNA has different bases than DNA.
B. RNA has a different sequence than DNA.
C. RNA is generally single-stranded.
D. Base pairs cannot form in RNA.
E. RNA is not capable of forming a double helix. Correct
Answers C. RNA is generally single-stranded.
Conservative model of DNA replication: Correct Answers The
parent DNA replicates itself. New DNA does not contain any
strands from parent DNA.
Double-stranded break is caused by what? Correct Answers
Ionizing radiation (X rays or gamma radiation) or anti-tumor
drugs
Double-stranded break: Why is end-joining "error-prone"?
Correct Answers 1. Recognition of broken ends
2. Exonucleases remove overhang nucleotides***
3. Ligation
This end joining creates errors; a lot of genetic information is
gone permanently.
