BIOLOGY 123 C4 EXAM QUESTIONS AND
100% VERIFIED CORRECT ANSWERS!!!
Describe the central dogma of molecular biology (DNA RNA Protein)
DNA Replication:
DNA is duplicated to pass genetic material to daughter cells during cell division.
Involves enzymes like DNA polymerase, helicase, primase, and ligase.
Transcription (DNA → RNA):
Carried out by RNA polymerase, which uses one strand of DNA (template strand) to
synthesize mRNA.
Begins at a promoter and ends at a terminator.
mRNA produced is complementary to the DNA template and resembles the coding strand.
Translation (RNA → Protein):
Occurs at the ribosome, where mRNA codons are matched with tRNA anticodons.
Each codon (3 RNA bases) corresponds to a specific amino acid, forming a polypeptide chain.
Begins at a start codon (AUG) and ends at a stop codon (UAA, UAG, UGA).
What is gene expression?
The process by which genetic information in DNA is used to produce a functional product,
usually a protein.
What is a gene?
A DNA segment that codes for RNA or protein.
Is all DNA expressed?
No, not all DNA is expressed; regulatory or noncoding regions control when and how much a
gene is expressed.
, What is mRNA's role in protein production?
mRNA (transcript) is translated multiple times, allowing for efficient protein production.
What does chromosomal DNA contain?
The core genetic blueprint necessary for the life and reproduction of the organism.
What is the function of plasmid DNA?
Provides extra capabilities, such as antibiotic resistance, that are beneficial but not essential.
In what situations is plasmid DNA especially useful?
In harsh environments or under selective pressure.
Describe the structure of DNA
DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a
sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T),
guanine (G) and cytosine (C).
Describe DNA replication
-DNA helicase splits the two strands by breaking hydrogen bonds
-DNA polymerase adds nucleotide bases from 5' to 3'
-Both strands act as a template
-On lagging strand, built in Okazaki fragments joined by DNA ligase
-occurs in both directions
What is the site where replication starts called?
Origin of replication (Ori)
What enzyme unzips the DNA helix during replication?
Helicase
What is the role of stabilizing proteins during DNA replication?
They keep the strands apart.
100% VERIFIED CORRECT ANSWERS!!!
Describe the central dogma of molecular biology (DNA RNA Protein)
DNA Replication:
DNA is duplicated to pass genetic material to daughter cells during cell division.
Involves enzymes like DNA polymerase, helicase, primase, and ligase.
Transcription (DNA → RNA):
Carried out by RNA polymerase, which uses one strand of DNA (template strand) to
synthesize mRNA.
Begins at a promoter and ends at a terminator.
mRNA produced is complementary to the DNA template and resembles the coding strand.
Translation (RNA → Protein):
Occurs at the ribosome, where mRNA codons are matched with tRNA anticodons.
Each codon (3 RNA bases) corresponds to a specific amino acid, forming a polypeptide chain.
Begins at a start codon (AUG) and ends at a stop codon (UAA, UAG, UGA).
What is gene expression?
The process by which genetic information in DNA is used to produce a functional product,
usually a protein.
What is a gene?
A DNA segment that codes for RNA or protein.
Is all DNA expressed?
No, not all DNA is expressed; regulatory or noncoding regions control when and how much a
gene is expressed.
, What is mRNA's role in protein production?
mRNA (transcript) is translated multiple times, allowing for efficient protein production.
What does chromosomal DNA contain?
The core genetic blueprint necessary for the life and reproduction of the organism.
What is the function of plasmid DNA?
Provides extra capabilities, such as antibiotic resistance, that are beneficial but not essential.
In what situations is plasmid DNA especially useful?
In harsh environments or under selective pressure.
Describe the structure of DNA
DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a
sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T),
guanine (G) and cytosine (C).
Describe DNA replication
-DNA helicase splits the two strands by breaking hydrogen bonds
-DNA polymerase adds nucleotide bases from 5' to 3'
-Both strands act as a template
-On lagging strand, built in Okazaki fragments joined by DNA ligase
-occurs in both directions
What is the site where replication starts called?
Origin of replication (Ori)
What enzyme unzips the DNA helix during replication?
Helicase
What is the role of stabilizing proteins during DNA replication?
They keep the strands apart.
