BIO 204 EXAM
1. What are the three main steps of PCR?: Denaturation, Annealing, Extension
2. What happens during the Denaturation step of PCR?: The DNA is heated to break
hydrogen bonds between base pairs, separating the two strands.
3. What happens during the Annealing step of PCR?: The temperature is lowered so that
primers can bind to the single-stranded DNA.
4. What happens during the Extension step of PCR?: Taq polymerase adds nucleotides to build
a new complementary strand of DNA.
5. What is the first step in extracting DNA from plant cells?: Homogenize leaf slivers in
Edwards Buffer to break open cell walls. (A-I: E, 1-9: 1)
6. Why is the DNA sample heated to 100°C?: To increase solubilization of membranes and denature
proteins. (A-I: D, 1-9: 4)
7. What happens after the sample is homogenized and heated?: Spin down the
homogenized sample to separate solids from the liquid. (A-I: H, 1-9: 9)
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, 8. Which part is kept after the first spin-down and why?: The supernatant is kept because it
contains the DNA. (A-I: F, 1-9: 8)
9. What is the purpose of adding isopropanol (IPA) to the supernatant?: It causes
the DNA to precipitate. (A-I: A, 1-9: 2)
10. What does spinning down precipitated DNA do?: It pellets the DNA so it can be separated.
(A-I: I, 1-9: 5)
11. After pelleting the DNA, what happens to the supernatant?: It is removed using IPA
and buffer, keeping only the DNA pellet. (A-I: C, 1-9: 6)
12. Why is the DNA pellet incubated at 37°C?: To dry and remove traces of IPA. (A-I: G, 1-9: 3)
13. What is added to the DNA pellet for PCR preparation?: TE buffer + RNaseA. (A-I: B, 1-9:
7)
14. Forceps: Allows you to grasp parts for cutting or pull things out of the way, such as during skin incisions.
15. Dissecting Needle: Used to tear connective tissue to separate organs.
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1. What are the three main steps of PCR?: Denaturation, Annealing, Extension
2. What happens during the Denaturation step of PCR?: The DNA is heated to break
hydrogen bonds between base pairs, separating the two strands.
3. What happens during the Annealing step of PCR?: The temperature is lowered so that
primers can bind to the single-stranded DNA.
4. What happens during the Extension step of PCR?: Taq polymerase adds nucleotides to build
a new complementary strand of DNA.
5. What is the first step in extracting DNA from plant cells?: Homogenize leaf slivers in
Edwards Buffer to break open cell walls. (A-I: E, 1-9: 1)
6. Why is the DNA sample heated to 100°C?: To increase solubilization of membranes and denature
proteins. (A-I: D, 1-9: 4)
7. What happens after the sample is homogenized and heated?: Spin down the
homogenized sample to separate solids from the liquid. (A-I: H, 1-9: 9)
1/2
, 8. Which part is kept after the first spin-down and why?: The supernatant is kept because it
contains the DNA. (A-I: F, 1-9: 8)
9. What is the purpose of adding isopropanol (IPA) to the supernatant?: It causes
the DNA to precipitate. (A-I: A, 1-9: 2)
10. What does spinning down precipitated DNA do?: It pellets the DNA so it can be separated.
(A-I: I, 1-9: 5)
11. After pelleting the DNA, what happens to the supernatant?: It is removed using IPA
and buffer, keeping only the DNA pellet. (A-I: C, 1-9: 6)
12. Why is the DNA pellet incubated at 37°C?: To dry and remove traces of IPA. (A-I: G, 1-9: 3)
13. What is added to the DNA pellet for PCR preparation?: TE buffer + RNaseA. (A-I: B, 1-9:
7)
14. Forceps: Allows you to grasp parts for cutting or pull things out of the way, such as during skin incisions.
15. Dissecting Needle: Used to tear connective tissue to separate organs.
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