ESSENTIAL CELL BIOLOGY CHAPTER
#5 EXAM QUESTIONS AND ANSWERS
Nucleolus - ANSWER-Large structure within the nucleus where ribosomal RNA is is
transcribed and ribosomal subunits are assembled.
Histone - ANSWER-One of a group of abundant highly conserved proteins around
which DNA wraps to form nucleosomes, structures that represent the most fundamental
level of chromatin packing.
Chromatin - ANSWER-Complex of DNA and proteins that makes up the chromosomes
in a eukaryotic cell.
Nucleosome - ANSWER-Beadlike structural unit of a eukaryotic chromosome
composed of a short length of DNA wrapped around a core of histone proteins; includes
a nucleosomal core particle along with a segment of linker DNA that ties the core
particles together.
Chromatin-Remodeling Complex - ANSWER-Enzyme that uses the energy of ATP
hydrolysis to alter the arrangement of nucleosomes in eukaryotic chromosomes,
changing the accessibility of the underlying DNA to other proteins, including those
involved in transcription.
Heterochromatin - ANSWER-Highly condensed region of an interphase chromosomes,
generally gene-poor and transcriptionally inactive.
Euchromatin - ANSWER-One of the two main states in which chromatin exists within an
interphase cell. Prevalent in gene-rich areas, its less compact structures allows access
for proteins involved in transcription.
DNA - ANSWER-Double stranded polynucleotide formed from two separate chains of
covalently linked deoxyribonucleic units. It serves as the cell's store of genetic
information that is transmitted from generation to generation.
Double Helix - ANSWER-The typical structure of a DNA molecule in which the two
complementary polynucleotide strands are wound around each other with base pairing
between the strands.
Base Pair - ANSWER-Two complementary nucleotides in an RNA or DNA molecule that
are held together by hydrogen bonds.
Complementary - ANSWER-Describes two molecular surfaces that fit together closely
and form noncovalent bonds with each other.
#5 EXAM QUESTIONS AND ANSWERS
Nucleolus - ANSWER-Large structure within the nucleus where ribosomal RNA is is
transcribed and ribosomal subunits are assembled.
Histone - ANSWER-One of a group of abundant highly conserved proteins around
which DNA wraps to form nucleosomes, structures that represent the most fundamental
level of chromatin packing.
Chromatin - ANSWER-Complex of DNA and proteins that makes up the chromosomes
in a eukaryotic cell.
Nucleosome - ANSWER-Beadlike structural unit of a eukaryotic chromosome
composed of a short length of DNA wrapped around a core of histone proteins; includes
a nucleosomal core particle along with a segment of linker DNA that ties the core
particles together.
Chromatin-Remodeling Complex - ANSWER-Enzyme that uses the energy of ATP
hydrolysis to alter the arrangement of nucleosomes in eukaryotic chromosomes,
changing the accessibility of the underlying DNA to other proteins, including those
involved in transcription.
Heterochromatin - ANSWER-Highly condensed region of an interphase chromosomes,
generally gene-poor and transcriptionally inactive.
Euchromatin - ANSWER-One of the two main states in which chromatin exists within an
interphase cell. Prevalent in gene-rich areas, its less compact structures allows access
for proteins involved in transcription.
DNA - ANSWER-Double stranded polynucleotide formed from two separate chains of
covalently linked deoxyribonucleic units. It serves as the cell's store of genetic
information that is transmitted from generation to generation.
Double Helix - ANSWER-The typical structure of a DNA molecule in which the two
complementary polynucleotide strands are wound around each other with base pairing
between the strands.
Base Pair - ANSWER-Two complementary nucleotides in an RNA or DNA molecule that
are held together by hydrogen bonds.
Complementary - ANSWER-Describes two molecular surfaces that fit together closely
and form noncovalent bonds with each other.
