BIO 101 EXAM 1 NVCC ACTUAL EXAM 100 REAL EXAM
QUESTIONS AND CORRECT DETAILED ANSWERS
What are the three parts of an atom? - ANSWER: Protons, neutrons, and electrons.
What determines the identity of an atom? - ANSWER: The number of protons.
How many protons does carbon have? - ANSWER: 6 protons.
What is the outer shell of an atom called? - ANSWER: The valence shell (orbital).
What is the octet rule? - ANSWER: The 2nd and 3rd shells are full with 8 electrons.
Why is carbon important in biological molecules? - ANSWER: Carbon has 4 valence
electrons, creating opportunities for many covalent bonds and a diversity of
molecules.
What type of bond results from unequal sharing of electrons? - ANSWER: Polar
covalent bond.
What gives water its special properties in biology? - ANSWER: The polar nature of
water and its ability to form hydrogen bonds.
Compare the strength of ionic bonds to hydrogen and covalent bonds. - ANSWER:
Ionic bonds are stronger than hydrogen bonds but weaker than covalent bonds.
Name three roles of proteins in organisms. - ANSWER: enzymes, structure and
support, energy storage, transport, hormones, receptors, motor (movement), or
defense.
What are proteins made of? - ANSWER: Long chains of amino acids.
How many different amino acids are used to make proteins? - ANSWER: 20 different
amino acids.
What type of bond connects amino acids in a protein? - ANSWER: Peptide bond.
What creates the secondary structure of a protein? - ANSWER: Hydrogen bonds.
What are the components of a DNA nucleotide? - ANSWER: Phosphate group,
deoxyribose sugar, and a base (A, G, T, or C).
How does an RNA nucleotide differ from a DNA nucleotide? - ANSWER: RNA has
ribose sugar instead of deoxyribose, and uses uracil (U) instead of thymine (T).
, What type of bond connects nucleotides in DNA and RNA? - ANSWER:
Phosphodiester bonds.
Name the two types of bases in DNA and RNA. - ANSWER: Pyrimidines and purines.
Which bases are pyrimidines? - ANSWER: Thymine, Cytosine, and Uracil.
Which bases are purines? - ANSWER: Adenine and Guanine.
How many hydrogen bonds are there between A-T and G-C base pairs? - ANSWER:
A-T has 2 hydrogen bonds, G-C has 3 hydrogen bonds.
What is the name for the active site of DNA replication? - ANSWER: Replication fork.
What enzyme is responsible for adding new nucleotides during DNA replication? -
ANSWER: DNA polymerase III.
What is the function of DNA ligase in DNA replication? - ANSWER: It fixes nicks or
creates the last bond in DNA replication.
What are the three steps in the central dogma of molecular biology? - ANSWER:
DNA → RNA → Protein (Transcription, then Translation)
Where does transcription occur in eukaryotic cells? - ANSWER: In the nucleus.
Where does translation occur in eukaryotic cells? - ANSWER: In the cytoplasm.
What is the function of RNA polymerase? - ANSWER: It makes RNA by adding
ribonucleotides to the 3' end during transcription.
What is the TATA box? - ANSWER: A short DNA sequence in the promoter region
where transcription is initiated.
What are introns and exons? - ANSWER: Introns are non-coding sequences within
genes that are removed during RNA splicing. Exons are coding sequences that
remain after splicing and are translated into proteins.
What is the function of helicase in DNA replication? - ANSWER: Helicase unwinds
the DNA double helix during replication.
What role does topoisomerase play in DNA replication? - ANSWER: Topoisomerase
releases tension upstream from the unwinding of DNA, preventing supercoiling.
What is the purpose of single-stranded binding proteins (SSBs) in DNA replication? -
ANSWER: SSBs keep the single-stranded DNA from interacting with anything else
during replication.
QUESTIONS AND CORRECT DETAILED ANSWERS
What are the three parts of an atom? - ANSWER: Protons, neutrons, and electrons.
What determines the identity of an atom? - ANSWER: The number of protons.
How many protons does carbon have? - ANSWER: 6 protons.
What is the outer shell of an atom called? - ANSWER: The valence shell (orbital).
What is the octet rule? - ANSWER: The 2nd and 3rd shells are full with 8 electrons.
Why is carbon important in biological molecules? - ANSWER: Carbon has 4 valence
electrons, creating opportunities for many covalent bonds and a diversity of
molecules.
What type of bond results from unequal sharing of electrons? - ANSWER: Polar
covalent bond.
What gives water its special properties in biology? - ANSWER: The polar nature of
water and its ability to form hydrogen bonds.
Compare the strength of ionic bonds to hydrogen and covalent bonds. - ANSWER:
Ionic bonds are stronger than hydrogen bonds but weaker than covalent bonds.
Name three roles of proteins in organisms. - ANSWER: enzymes, structure and
support, energy storage, transport, hormones, receptors, motor (movement), or
defense.
What are proteins made of? - ANSWER: Long chains of amino acids.
How many different amino acids are used to make proteins? - ANSWER: 20 different
amino acids.
What type of bond connects amino acids in a protein? - ANSWER: Peptide bond.
What creates the secondary structure of a protein? - ANSWER: Hydrogen bonds.
What are the components of a DNA nucleotide? - ANSWER: Phosphate group,
deoxyribose sugar, and a base (A, G, T, or C).
How does an RNA nucleotide differ from a DNA nucleotide? - ANSWER: RNA has
ribose sugar instead of deoxyribose, and uses uracil (U) instead of thymine (T).
, What type of bond connects nucleotides in DNA and RNA? - ANSWER:
Phosphodiester bonds.
Name the two types of bases in DNA and RNA. - ANSWER: Pyrimidines and purines.
Which bases are pyrimidines? - ANSWER: Thymine, Cytosine, and Uracil.
Which bases are purines? - ANSWER: Adenine and Guanine.
How many hydrogen bonds are there between A-T and G-C base pairs? - ANSWER:
A-T has 2 hydrogen bonds, G-C has 3 hydrogen bonds.
What is the name for the active site of DNA replication? - ANSWER: Replication fork.
What enzyme is responsible for adding new nucleotides during DNA replication? -
ANSWER: DNA polymerase III.
What is the function of DNA ligase in DNA replication? - ANSWER: It fixes nicks or
creates the last bond in DNA replication.
What are the three steps in the central dogma of molecular biology? - ANSWER:
DNA → RNA → Protein (Transcription, then Translation)
Where does transcription occur in eukaryotic cells? - ANSWER: In the nucleus.
Where does translation occur in eukaryotic cells? - ANSWER: In the cytoplasm.
What is the function of RNA polymerase? - ANSWER: It makes RNA by adding
ribonucleotides to the 3' end during transcription.
What is the TATA box? - ANSWER: A short DNA sequence in the promoter region
where transcription is initiated.
What are introns and exons? - ANSWER: Introns are non-coding sequences within
genes that are removed during RNA splicing. Exons are coding sequences that
remain after splicing and are translated into proteins.
What is the function of helicase in DNA replication? - ANSWER: Helicase unwinds
the DNA double helix during replication.
What role does topoisomerase play in DNA replication? - ANSWER: Topoisomerase
releases tension upstream from the unwinding of DNA, preventing supercoiling.
What is the purpose of single-stranded binding proteins (SSBs) in DNA replication? -
ANSWER: SSBs keep the single-stranded DNA from interacting with anything else
during replication.
