BIO111
Biology Laboratory
Midterms Exam Review (Qns & Ans)
2025
1. Which of the following techniques is commonly used to
amplify DNA sequences in a laboratory setting?
- A. Gel electrophoresis
- B. Polymerase chain reaction (PCR)
- C. Spectrophotometry
- D. Centrifugation
ANS: B. Polymerase chain reaction (PCR)
©/2025
, Rationale: PCR is a technique used to amplify specific DNA
sequences, making it possible to generate millions of copies from
a small sample of DNA.
2. What is the primary purpose of using a spectrophotometer in a
biology laboratory?
- A. To measure the concentration of solutes in a solution
- B. To separate DNA fragments
- C. To visualize cells under a microscope
- D. To sterilize laboratory equipment
ANS: A. To measure the concentration of solutes in a solution
Rationale: A spectrophotometer measures the absorbance of
light by a solution, which is used to determine the concentration
of solutes present.
Fill-in-the-Blank Questions
3. __________ is a technique used to separate and visualize
proteins based on their size and charge.
ANS: SDS-PAGE (Sodium Dodecyl Sulfate Polyacrylamide
Gel Electrophoresis)
©/2025
, Rationale: SDS-PAGE separates proteins based on their size
and charge by applying an electric field to a gel matrix.
4. The process of transferring DNA from a gel to a membrane
for further analysis, such as hybridization, is called __________.
ANS: Southern blotting
Rationale: Southern blotting is a technique used to transfer
DNA fragments from a gel to a membrane for subsequent
analysis, such as hybridization with a labeled probe.
True/False Questions
5. True or False: A micropipette is used to measure and transfer
very small volumes of liquid with high precision.
ANS: True
Rationale: A micropipette is designed to measure and transfer
very small volumes of liquid accurately and precisely, typically in
the microliter range.
6. True or False: Gram staining is a technique used to
differentiate bacterial species based on the thickness of their cell
walls.
©/2025
, ANS: True
Rationale: Gram staining differentiates bacterial species
based on the thickness of their cell walls; Gram-positive bacteria
retain the crystal violet stain, while Gram-negative bacteria do
not.
Multiple Response Questions
7. Which of the following safety practices should be followed in
a biology laboratory? (Select all that apply)
- A. Wearing personal protective equipment (PPE)
- B. Eating and drinking at the lab bench
- C. Proper disposal of biological waste
- D. Handling chemicals without gloves
ANSs: A, C
Rationale: Safety practices in a biology laboratory include
wearing personal protective equipment (PPE) and properly
disposing of biological waste. Eating and drinking at the lab
bench and handling chemicals without gloves are unsafe
practices.
©/2025
Biology Laboratory
Midterms Exam Review (Qns & Ans)
2025
1. Which of the following techniques is commonly used to
amplify DNA sequences in a laboratory setting?
- A. Gel electrophoresis
- B. Polymerase chain reaction (PCR)
- C. Spectrophotometry
- D. Centrifugation
ANS: B. Polymerase chain reaction (PCR)
©/2025
, Rationale: PCR is a technique used to amplify specific DNA
sequences, making it possible to generate millions of copies from
a small sample of DNA.
2. What is the primary purpose of using a spectrophotometer in a
biology laboratory?
- A. To measure the concentration of solutes in a solution
- B. To separate DNA fragments
- C. To visualize cells under a microscope
- D. To sterilize laboratory equipment
ANS: A. To measure the concentration of solutes in a solution
Rationale: A spectrophotometer measures the absorbance of
light by a solution, which is used to determine the concentration
of solutes present.
Fill-in-the-Blank Questions
3. __________ is a technique used to separate and visualize
proteins based on their size and charge.
ANS: SDS-PAGE (Sodium Dodecyl Sulfate Polyacrylamide
Gel Electrophoresis)
©/2025
, Rationale: SDS-PAGE separates proteins based on their size
and charge by applying an electric field to a gel matrix.
4. The process of transferring DNA from a gel to a membrane
for further analysis, such as hybridization, is called __________.
ANS: Southern blotting
Rationale: Southern blotting is a technique used to transfer
DNA fragments from a gel to a membrane for subsequent
analysis, such as hybridization with a labeled probe.
True/False Questions
5. True or False: A micropipette is used to measure and transfer
very small volumes of liquid with high precision.
ANS: True
Rationale: A micropipette is designed to measure and transfer
very small volumes of liquid accurately and precisely, typically in
the microliter range.
6. True or False: Gram staining is a technique used to
differentiate bacterial species based on the thickness of their cell
walls.
©/2025
, ANS: True
Rationale: Gram staining differentiates bacterial species
based on the thickness of their cell walls; Gram-positive bacteria
retain the crystal violet stain, while Gram-negative bacteria do
not.
Multiple Response Questions
7. Which of the following safety practices should be followed in
a biology laboratory? (Select all that apply)
- A. Wearing personal protective equipment (PPE)
- B. Eating and drinking at the lab bench
- C. Proper disposal of biological waste
- D. Handling chemicals without gloves
ANSs: A, C
Rationale: Safety practices in a biology laboratory include
wearing personal protective equipment (PPE) and properly
disposing of biological waste. Eating and drinking at the lab
bench and handling chemicals without gloves are unsafe
practices.
©/2025
