Chapter 11 Flashcards
which term describes the territory structural organization of chromosomal DNA that allows the long strand to be packed and fit into the cytoplasm of the cell?
supercoiling
which statement about cellular DNA is incorrect?
supercoiling of cellular DNA is controlled by topoisomerase
supercoiling allows cellular DNA to be packed into a small space
DNA exists in the cell as very long, tightly packed molecules
supercoiling makes the separation of the two strands of DNA easier for replication and transcription
most cellular DNA is positively supercoiled
most cellular DNA is positively supercoiled
which statements about euchromatin and heterochromatin are correct
euchromatin undergoes condensation and decondensation through the cell cycle
the majority of transcription takes place on euchromatin
most of the centromere and telomere structures consist of
heterochromatin
describe prokaryotic DNA structure
DNA is circular
condensed only by DNA supercoiling
arranged in a single looped structure
does not have telomere region
describe eukaryotic DNA structure
DNA is linear
condensed around histone proteins
arranged in multiple chromosomes
has repeating telomere region
in a circular bacterial chromosome, the structure of DNA is a ___ double helix
right handed
if DNA is twisted in the ____ direction, it becomes overwound
right handed
overwinding results in ____ supercoiling
positive
if DNA is twisted in the _____ direction, it becomes underwound
left handed
underwinding results in _____ supercoiling
negative
heterochromatin
the denser form of chromatin
the type of chromatin that is not usually transcribed
euchromatin
the looser form of chromatin
the type of chromatin that is most often transcribed
arrange the features of eukaryotic chromosome packaging in order form the smallest unit to the largest unit
base pair nucleosome coiled fiber chromosome genome
histone proteins
attach to DNA and from compacted DNA- protein associations
the less condensed form of chromatin is
euchromatin
the inactive form of chromatin is
heterochromatin
a core composed of ____ proteins interacts with DNA through hydrogen bonding and ionic bonds
histone
if DNA structure is described as “beads on a string” , a “bead” is a
histone
the more darkly staining form of a chromatin is
heterochromatin
if DNA structure is describe as “ beads on a string”, the “string” is the
DNA molecule
a_____ is a DNA -protien complex
nucleosome
DNA is wrapped around histone proteins and coiled to form a dense fiber called chromatin.
which statements describes the function of the chromatin conformation of DNA?
DNA is wrapped around histone proteins to regulate gene expression
how does chromosome compaction differ during metaphase and interphase in eukaryotes?
chromosomes are more compacted in metaphase than in interphase
what is the function of the centromere in the transmission of genetic information?
the attachment point for sister chromatids