1|Page
BCHM 4360 EXAM 1 NEWEST 2025/ 2026 ACTUAL
EXAM COMPLETE 180 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||NEWEST UPDATE!!!
The position of chromosome territories may be related to
the position of chromosomes just after what event? -
ANSWER-mitosis
True or False: When transcription on a certain
chromosome increases, its territory size decreases. -
ANSWER-False: increases
True or False: Genes are only transcribed during
interphase because mitosis is focused on division. -
ANSWER-False: genes are transcribed whenever the cell
needs them to be
Chromosomes can ______, replicate, and then ______
back together in pretty much the same structure. -
ANSWER-unfold, refold
Are heterochromatic regions often found near the nuclear
envelope or the middle of the nucleus? - ANSWER-
nuclear envelope
,2|Page
Human chromosomes 18 and 19 are similar in size. Gene-
rich 19 is found near the ______ of the nucleus whereas
gene-poor 18 is at the _________ of the nucleus. -
ANSWER-center, periphery
True or False: A gene can be silenced if brought into the
proximity of heterochromatin, even on another
chromosome. - ANSWER-True
If a small region of heterochromatin is inserted into a
certain locus of one copy, what happens to the other
copy? - ANSWER-It is also silenced, probably due to the
relocation of the region containing the locus to a
heterochromatic region of the nucleus
True or False: The nucleolus is a membrane-bound
organelle that sits in the middle of the nucleus. -
ANSWER-False: the nucleolus is not separated by a
membrane
What was Kornberg attempting to solve? - ANSWER-The
arrangement of histones and DNA
Describe the steps of Kornberg experiment. - ANSWER-
Micrococal nuclease digestion was used to test a model of
,3|Page
the way DNA is packaged into chromatin. Exposed ds-
DNA is digested by the nuclease but regions wrapped
around the histones are protected. After digestion, the
remaining intact DNA can be visualized by gel
electrophoresis.
What were the main results of the Kornberg experiment? -
ANSWER-Two different sized bands were produced. One
was about 170bp and the other was about 205bp. The
shorter fragments resulted from "nibbling" up to the
histone octamer by the nuclease. The longer fragments
results from "multiples" - where the nuclease did not cut
between one or more histone octamers
What were the steps and the conclusion of the Mavrich
experiment? - ANSWER-Modern sequencing allowed
identification of the DNA sequences wrapped around
histones. Histones were chemically linked to DNA. DNA
was digested and histone-linked DNA was isolated using
histone antibodies. Histones were removed and the DNA
sequenced. The DNA was mapped onto chromosomes.
Showed that promoter and terminator regions of yeast
genes are relatively free of histones.
What did the Brownell and Allis paper do and find? -
ANSWER-The enzyme that acetylates histones was
, 4|Page
discovered using an assay with a histone-impregnated gel.
Proteins were separated on the gel, then SDS removed to
allow proteins to re-fold and regain activity. Labeled
acetyl-CoA was added to the gel, and peptide sequences
identified from a protein that could add the label to the
histones. Peptide sequences allowed the gene to be
identified and cloned by PCR methods.
How were histone modifications mapped to the human
genome? - ANSWER-Using a nuclease technique with
antibodies that are highly specific for different histone
modifications
How did Clarke and Carbon determine the molecular
structure for centromeres? - ANSWER-Regions of DNA
from chromosome III were transferred into the ARS
plasmid and examined for segregation into daughter cells
after division. Chromosome walking was used to isolate
overlapping regions of the centromeric region for insertion
into the plasmid. Regions were narrowed down to a 1.6kb
region that conferred segregation. The identified
centromeric piece of DNA also conferred meiotic stability.
Yeast cells containing the plasmid were able to survive
without histidine due to the presence of a histidine gene
on the plasmid.
BCHM 4360 EXAM 1 NEWEST 2025/ 2026 ACTUAL
EXAM COMPLETE 180 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||NEWEST UPDATE!!!
The position of chromosome territories may be related to
the position of chromosomes just after what event? -
ANSWER-mitosis
True or False: When transcription on a certain
chromosome increases, its territory size decreases. -
ANSWER-False: increases
True or False: Genes are only transcribed during
interphase because mitosis is focused on division. -
ANSWER-False: genes are transcribed whenever the cell
needs them to be
Chromosomes can ______, replicate, and then ______
back together in pretty much the same structure. -
ANSWER-unfold, refold
Are heterochromatic regions often found near the nuclear
envelope or the middle of the nucleus? - ANSWER-
nuclear envelope
,2|Page
Human chromosomes 18 and 19 are similar in size. Gene-
rich 19 is found near the ______ of the nucleus whereas
gene-poor 18 is at the _________ of the nucleus. -
ANSWER-center, periphery
True or False: A gene can be silenced if brought into the
proximity of heterochromatin, even on another
chromosome. - ANSWER-True
If a small region of heterochromatin is inserted into a
certain locus of one copy, what happens to the other
copy? - ANSWER-It is also silenced, probably due to the
relocation of the region containing the locus to a
heterochromatic region of the nucleus
True or False: The nucleolus is a membrane-bound
organelle that sits in the middle of the nucleus. -
ANSWER-False: the nucleolus is not separated by a
membrane
What was Kornberg attempting to solve? - ANSWER-The
arrangement of histones and DNA
Describe the steps of Kornberg experiment. - ANSWER-
Micrococal nuclease digestion was used to test a model of
,3|Page
the way DNA is packaged into chromatin. Exposed ds-
DNA is digested by the nuclease but regions wrapped
around the histones are protected. After digestion, the
remaining intact DNA can be visualized by gel
electrophoresis.
What were the main results of the Kornberg experiment? -
ANSWER-Two different sized bands were produced. One
was about 170bp and the other was about 205bp. The
shorter fragments resulted from "nibbling" up to the
histone octamer by the nuclease. The longer fragments
results from "multiples" - where the nuclease did not cut
between one or more histone octamers
What were the steps and the conclusion of the Mavrich
experiment? - ANSWER-Modern sequencing allowed
identification of the DNA sequences wrapped around
histones. Histones were chemically linked to DNA. DNA
was digested and histone-linked DNA was isolated using
histone antibodies. Histones were removed and the DNA
sequenced. The DNA was mapped onto chromosomes.
Showed that promoter and terminator regions of yeast
genes are relatively free of histones.
What did the Brownell and Allis paper do and find? -
ANSWER-The enzyme that acetylates histones was
, 4|Page
discovered using an assay with a histone-impregnated gel.
Proteins were separated on the gel, then SDS removed to
allow proteins to re-fold and regain activity. Labeled
acetyl-CoA was added to the gel, and peptide sequences
identified from a protein that could add the label to the
histones. Peptide sequences allowed the gene to be
identified and cloned by PCR methods.
How were histone modifications mapped to the human
genome? - ANSWER-Using a nuclease technique with
antibodies that are highly specific for different histone
modifications
How did Clarke and Carbon determine the molecular
structure for centromeres? - ANSWER-Regions of DNA
from chromosome III were transferred into the ARS
plasmid and examined for segregation into daughter cells
after division. Chromosome walking was used to isolate
overlapping regions of the centromeric region for insertion
into the plasmid. Regions were narrowed down to a 1.6kb
region that conferred segregation. The identified
centromeric piece of DNA also conferred meiotic stability.
Yeast cells containing the plasmid were able to survive
without histidine due to the presence of a histidine gene
on the plasmid.
