MMSC 491 EXAM 1 VERIFIED STUDY GUIDE
DNA base pairing - Answers - DNA bases pair specifically with each other so that
genetic information can be copied accurately.
Complementary base pairing - Answers - Adenine pairs with thymine and guanine pairs
with cytosine.
A-T base pairing - Answers - Adenine pairs with thymine using two hydrogen bonds.
G-C base pairing - Answers - Guanine pairs with cytosine using three hydrogen bonds,
making it slightly stronger.
Hydrogen bonds in DNA - Answers - Weak bonds between complementary bases that
hold DNA strands together but allow them to separate during replication.
Antiparallel DNA strands - Answers - DNA strands run in opposite directions (one 5′→3′
and the other 3′→5′).
DNA replication - Answers - The process of copying DNA before cell division.
Purpose of DNA replication - Answers - To ensure both daughter cells receive identical
genetic information.
Semi-conservative replication - Answers - Each new DNA molecule contains one
original strand and one newly synthesized strand.
Template strand - Answers - The original DNA strand used to guide synthesis of a new
strand.
Replication fork - Answers - Y-shaped region where DNA strands separate and
replication occurs.
DNA helicase - Answers - Enzyme that unwinds the DNA double helix.
Single strand binding proteins - Answers - Proteins that keep separated DNA strands
stable.
DNA polymerase - Answers - Enzyme that synthesizes new DNA strands.
Direction of DNA synthesis - Answers - DNA polymerase synthesizes DNA in the 5′→3′
direction.
RNA primer - Answers - Short RNA segment required to start DNA synthesis.
, Primase - Answers - Enzyme that creates RNA primers.
Leading strand - Answers - DNA strand synthesized continuously.
Lagging strand - Answers - DNA strand synthesized in fragments.
Okazaki fragments - Answers - Short DNA segments produced on the lagging strand.
DNA ligase - Answers - Enzyme that joins Okazaki fragments together.
Epigenetics - Answers - Changes in gene expression that occur without altering the
DNA sequence.
DNA methylation - Answers - Addition of a methyl group (CH₃) to DNA.
Cytosine methylation - Answers - Methyl groups are typically added to cytosine bases.
CpG sites - Answers - DNA regions where cytosine is followed by guanine; common
methylation sites.
Effect of DNA methylation - Answers - Often reduces gene expression by preventing
transcription.
Epigenetic inheritance - Answers - Epigenetic modifications can be passed to daughter
cells.
Chromosome - Answers - A DNA molecule packaged with proteins that carries genetic
information.
Chromatin - Answers - DNA combined with histone proteins.
Histones - Answers - Proteins that DNA wraps around to form nucleosomes.
Nucleosome - Answers - DNA wrapped around histone proteins.
Chromosomal aberration - Answers - Structural change in chromosomes.
Deletion - Answers - Loss of a chromosome segment.
Duplication - Answers - Extra copy of a DNA region.
Inversion - Answers - A chromosome segment is reversed.
Translocation - Answers - DNA segment moves to a different chromosome.
DNA base pairing - Answers - DNA bases pair specifically with each other so that
genetic information can be copied accurately.
Complementary base pairing - Answers - Adenine pairs with thymine and guanine pairs
with cytosine.
A-T base pairing - Answers - Adenine pairs with thymine using two hydrogen bonds.
G-C base pairing - Answers - Guanine pairs with cytosine using three hydrogen bonds,
making it slightly stronger.
Hydrogen bonds in DNA - Answers - Weak bonds between complementary bases that
hold DNA strands together but allow them to separate during replication.
Antiparallel DNA strands - Answers - DNA strands run in opposite directions (one 5′→3′
and the other 3′→5′).
DNA replication - Answers - The process of copying DNA before cell division.
Purpose of DNA replication - Answers - To ensure both daughter cells receive identical
genetic information.
Semi-conservative replication - Answers - Each new DNA molecule contains one
original strand and one newly synthesized strand.
Template strand - Answers - The original DNA strand used to guide synthesis of a new
strand.
Replication fork - Answers - Y-shaped region where DNA strands separate and
replication occurs.
DNA helicase - Answers - Enzyme that unwinds the DNA double helix.
Single strand binding proteins - Answers - Proteins that keep separated DNA strands
stable.
DNA polymerase - Answers - Enzyme that synthesizes new DNA strands.
Direction of DNA synthesis - Answers - DNA polymerase synthesizes DNA in the 5′→3′
direction.
RNA primer - Answers - Short RNA segment required to start DNA synthesis.
, Primase - Answers - Enzyme that creates RNA primers.
Leading strand - Answers - DNA strand synthesized continuously.
Lagging strand - Answers - DNA strand synthesized in fragments.
Okazaki fragments - Answers - Short DNA segments produced on the lagging strand.
DNA ligase - Answers - Enzyme that joins Okazaki fragments together.
Epigenetics - Answers - Changes in gene expression that occur without altering the
DNA sequence.
DNA methylation - Answers - Addition of a methyl group (CH₃) to DNA.
Cytosine methylation - Answers - Methyl groups are typically added to cytosine bases.
CpG sites - Answers - DNA regions where cytosine is followed by guanine; common
methylation sites.
Effect of DNA methylation - Answers - Often reduces gene expression by preventing
transcription.
Epigenetic inheritance - Answers - Epigenetic modifications can be passed to daughter
cells.
Chromosome - Answers - A DNA molecule packaged with proteins that carries genetic
information.
Chromatin - Answers - DNA combined with histone proteins.
Histones - Answers - Proteins that DNA wraps around to form nucleosomes.
Nucleosome - Answers - DNA wrapped around histone proteins.
Chromosomal aberration - Answers - Structural change in chromosomes.
Deletion - Answers - Loss of a chromosome segment.
Duplication - Answers - Extra copy of a DNA region.
Inversion - Answers - A chromosome segment is reversed.
Translocation - Answers - DNA segment moves to a different chromosome.
