BIO 243 Lab Final Exam Questions with Correct Answers Latest Update 2025/2026
What is the DNA chain made of? What are the parts? - Answers The DNA chain is made of
deoxyribonucleotides. The three parts are N-bases, sugar, and phosphate group(s).
Name the pyrimidines. How many ring structures do they have? - Answers Thymine and
Cytosine. They are single ring structures.
Name the purines. How many ring structures do they have? - Answers Adenine and Guanine.
They are double ring structures.
How many hydrogen bonds does adenine and thymine have? - Answers Two
How many hydrogen bonds does cytosine and guanine have? - Answers Three
Through which bond are the P-group and the N-base bonded to the sugar? and on which carbon?
- Answers Through covalent bonding. For the N-base, it bonds onto the C-1' and for the P- group,
it bonds onto the C-5'.
Which bond joins the two strands of DNA together? - Answers Hydrogen bonds
What does one nucleotide consist of? - Answers A sugar, one base, and a phosphate group.
What is the phosphodiester bond? Characteristics? Direction? - Answers It is when
deoxyribonucleotides get joined together through covalent bonds. It goes from 5'-3', and you
add new nucleotides to the 3' end of the previous nucleotide present in the DNA chain. It is
important for DNA replication to start, and is catalyzed by DNA polymerases.
What is the external structures of the DNA responsible for? - Answers DNA synthesis, gives a
framework for supporting the overall structure of the DNA molecule.
What is the internal structures of the DNA responsible for? - Answers Storage of genetic
information in the N bases, central dogma.
The DNA strand generated during replication of a template strand is called the
a)
cooperative strand
b)
anti-sense strand
c)
non-template strand
, d)
complimentary strand - Answers d) complimentary strand
DNA molecules are wound around proteins called... - Answers histones
In order to extract the DNA from the strawberry, we added detergent (NaCl). Why? Give 2
reasons - Answers 1. break the bonds and lyse the cell
2. denature histones (proteins) separating the DNA
The purpose of using high salt concentration during a DNA extraction is to...(give 2 reasons) -
Answers 1. strip away any proteins that are associated with the DNA
2. make DNA more soluble in water
Why was isopropanol added to the solution, containing strawberry and detergent? - Answers
decrease DNA polarity (less soluble) to create a precipitation of DNA
Why did we use strawberries in the lab? - Answers They contain many copies of chromosomes;
polyploidy (more than two paired homologous chromosomes), compared to humans that are
diploid. Also, the more amount of DNA makes it easier to extract.
How was it confirmed that we extracted DNA since it is colourless? - Answers We had to add
SYBR gold die which only bound to double stranded DNA and let out blue lights
What were the three case studies after we added the SYBR gold die? - Answers Dye added to
water, DNA, or denatured DNA.
How did we get denatured DNA? - Answers In order to denature the DNA, NaOH was added
since it's a strong base, so it takes our protons from the N-bases of DNA, and wrecks the
hydrogen bonding, which breaks the stability of the DNA structure.
Which case emit the most fluorescence light? - Answers normal DNA
Which of the following properties can we exploit to efficiently purify and visualize DNA? Select
all that apply.
A.)DNA-interacting proteins have positive charges that can be neutralized by negatively-charged
ions from salts
B.)Double-stranded DNA has two anti-parallel strands, making it a polar molecule
C.)DNA is colourless to the naked eye
D.)Cell membranes are made of lipids that can be disrupted by detergents
E.)DNA is condensed into chromatin in order to fit ~2 metres of length into a single nucleus (in
What is the DNA chain made of? What are the parts? - Answers The DNA chain is made of
deoxyribonucleotides. The three parts are N-bases, sugar, and phosphate group(s).
Name the pyrimidines. How many ring structures do they have? - Answers Thymine and
Cytosine. They are single ring structures.
Name the purines. How many ring structures do they have? - Answers Adenine and Guanine.
They are double ring structures.
How many hydrogen bonds does adenine and thymine have? - Answers Two
How many hydrogen bonds does cytosine and guanine have? - Answers Three
Through which bond are the P-group and the N-base bonded to the sugar? and on which carbon?
- Answers Through covalent bonding. For the N-base, it bonds onto the C-1' and for the P- group,
it bonds onto the C-5'.
Which bond joins the two strands of DNA together? - Answers Hydrogen bonds
What does one nucleotide consist of? - Answers A sugar, one base, and a phosphate group.
What is the phosphodiester bond? Characteristics? Direction? - Answers It is when
deoxyribonucleotides get joined together through covalent bonds. It goes from 5'-3', and you
add new nucleotides to the 3' end of the previous nucleotide present in the DNA chain. It is
important for DNA replication to start, and is catalyzed by DNA polymerases.
What is the external structures of the DNA responsible for? - Answers DNA synthesis, gives a
framework for supporting the overall structure of the DNA molecule.
What is the internal structures of the DNA responsible for? - Answers Storage of genetic
information in the N bases, central dogma.
The DNA strand generated during replication of a template strand is called the
a)
cooperative strand
b)
anti-sense strand
c)
non-template strand
, d)
complimentary strand - Answers d) complimentary strand
DNA molecules are wound around proteins called... - Answers histones
In order to extract the DNA from the strawberry, we added detergent (NaCl). Why? Give 2
reasons - Answers 1. break the bonds and lyse the cell
2. denature histones (proteins) separating the DNA
The purpose of using high salt concentration during a DNA extraction is to...(give 2 reasons) -
Answers 1. strip away any proteins that are associated with the DNA
2. make DNA more soluble in water
Why was isopropanol added to the solution, containing strawberry and detergent? - Answers
decrease DNA polarity (less soluble) to create a precipitation of DNA
Why did we use strawberries in the lab? - Answers They contain many copies of chromosomes;
polyploidy (more than two paired homologous chromosomes), compared to humans that are
diploid. Also, the more amount of DNA makes it easier to extract.
How was it confirmed that we extracted DNA since it is colourless? - Answers We had to add
SYBR gold die which only bound to double stranded DNA and let out blue lights
What were the three case studies after we added the SYBR gold die? - Answers Dye added to
water, DNA, or denatured DNA.
How did we get denatured DNA? - Answers In order to denature the DNA, NaOH was added
since it's a strong base, so it takes our protons from the N-bases of DNA, and wrecks the
hydrogen bonding, which breaks the stability of the DNA structure.
Which case emit the most fluorescence light? - Answers normal DNA
Which of the following properties can we exploit to efficiently purify and visualize DNA? Select
all that apply.
A.)DNA-interacting proteins have positive charges that can be neutralized by negatively-charged
ions from salts
B.)Double-stranded DNA has two anti-parallel strands, making it a polar molecule
C.)DNA is colourless to the naked eye
D.)Cell membranes are made of lipids that can be disrupted by detergents
E.)DNA is condensed into chromatin in order to fit ~2 metres of length into a single nucleus (in
