Chapter 5 Flashcards
(90 cards)
1
Q
highly coordinated sequence of events that
occurs during division process
A
cell cycle
2
Q
cell cycle of somatic cells
A
G1 - cell growth
S - DNA replication
G2 - prepare of mitosis
M - chromosome segregation
3
Q
sister chromatids are
separated and delivered to pole of the cell
A
chromosome segregation
4
Q
division of mother cell into two daughter
cells (equal chromosome)
A
cytokinesis
5
Q
Chromosome replicates and becomes highly
condensed; separate two daughter nuclei
A
interphase
6
Q
Highly condensed chromosomes in dividing cell
are known
A
mitotic chromosomes
7
Q
long, thin tangled threads in the
nucleus
A
chromatin
8
Q
Nuclear membrane is disassembled
A
Mitotic phase
9
Q
spindle organize SC pair in the center
of the cell
A
kinetochore
10
Q
Set of chromosomes is encapsulated by nuclear
membrane and the cells divide into
A
two daughter cells
11
Q
is a dynamic structure that can be
condensed and extended throughout the cell cycle
A
chromosome
12
Q
Microscope images of metaphase chromosome
when the SC are maximally condensed but have not
yet separated
A
karyotype
13
Q
Display of chromosome, lined up from largest to
smallest
A
karyotype
14
Q
total DNA content of cell and divided
among one or more chromosomes
A
cell genome
15
Q
organize, store, and transmit genetic
information compacted that fit within the cells
A
chromosome
16
Q
DNA is organized compatible with myriad DNA-based
process
A
replication, transcription, repair, and
recombination
17
Q
is double-stranded DNA molecule with
proteins that condense and organize DNA within the cel
A
chromosome
18
Q
bends the DNA during binding of small basic
proteins to have more compact structure
A
Bacteria
19
Q
compact bacterial chromosome
A
nucleoid
20
Q
is denser centrally than radially
A
Nucleoid
21
Q
may influence the shape
in these stages
A
Longitudinal confinement
22
Q
Two types of global nucleoid-wide dynamics make the
nucleoid more?
A
fluid
23
Q
Cell length increases _______ during growth
A
monotonically
24
Q
are implicated in sister segregation
A
Global cycles
25
Specifically the heterogeneous class of abundant
proteins called
nucleoid-associated proteins
(NAPs)
26
bind nonspecifically across bacterial genomes,
wrapping, bending, or bridging DNA
nucleoid-associated proteins
27
is small protein that can bridge DNA which
separate loci on the primary sequence level into close
physical proximity
E.coli H-NS
28
mall, abundant (~30,000 copies/cell) NAP found in
bacteria that coats and wraps chromosomal DNA around
itself, grossly similar to histones
HU
29
inserts conserved proline residues into the minor
groove of DNA, inducing sharp bend in the DNA
HU
30
two other protein that can also sharply
bend DNA
Integration Host Factor (IHF) and Factor for Inversion
Stimulation (FIS)
31
can alter DNA shape and facilitate the formation
of loops, frequently bring RNA polymerase together
with distant regulatory proteins
Integration host factor
32
affects DNA replication, initiation, and
recombination
Integration host factor
33
binds genome affecting transcription, replication,
and recombination and also influence chromosome compaction
and organization
Factor for inversion stimulation
34
is deceptively simple in its superficial
appearance
Viral particle
35
is contained within a capsid, which is
a symmetrical or quasisymmetrical structure assembled
from one or only a few proteins.
Nucleic acid genome
36
two-layer disk that is a circular structure; it
forms at a helix as it interacts with the RNA
Capsid
37
inserts into the central hole in the disk,
and the disk changes conformation into a helical
structure that surrounds the RNA
RNA hairpin
38
what are the examples of spherical capsids of DNA virus
phaga lambada and T4
39
is assembled from small set
proteins
empty headshell
40
is inserted in the head with structural changes in capsid
duplex genome
41
what are the general rules ( in order) in packing of DNA into head
prohead 1 has protein core - protein II is empty - DNA packing begins - headshell expands as DNA enters - headshell matches full size - tail is attached
42
maternal and paternal
chromosomes of a pair
homologous chromosomes
43
the only nonhomologous
chromosome pairs; X from mother, Y from father
sex chromosomes
44
Packaging of DNA inside the nucleus is through the
association od DNA with histones proteins to form
nucleoprotein complex known as
chromatin
45
is the fundamental repeating unit of
chromatin
nucleosome
46
long string of nucleosome;
first level of chromatin
beads on the string
47
disk-like protein
complex in the center of nucleosome
histone octamer / core particle
48
length of nucleosome fiber
10 nm fiber
49
is required to interact with chromosomal
proteins, they represent some of the highly conserved
proteins in eukaryotes
Core histones
50
– common protein fold in all 4 core
histones
histone fold
51
Each core histone protein has an _______ that
extends away from the nucleosome core between the coils
of DNA
N-terminal tail
52
N-terminal tail carry ________ which help to
interact with negative charged DNA.
lysine and arginine
53
helps to stabilize the
overall histone-DNA assembly
electrostatic interaction
54
histones encoded by these
genes
canonical histones
55
HV often replace canonical histones during
chromatin metabolism which known as
replacement variants
56
is generally less diverse than those that arise
from H2A and H2B families
H3
57
is the most diverse family of core histone proteins
and accompanied by substantial variation in their aminoand carboxy- terminal tail regions
H2A
58
most diverse of all histones and
represented by 11 isoforms in mice and 10 isoforms in
humans (7 somatic & 3 germline-specific variants)
H1
59
confers unique properties on chromatin structure by
promoting differential interactions with various associated
complex proteins
HV
60
consecutive nucleosomes are adjacent
to one another in the fiber and is folded into one-start
helix
Solenoid model
61
Nucleosomes are arranged in zigzag
manner
Two start helix
62
Further compaction of 30-nm fiber involves folding of
fibers to series of
loops and coils
63
suggests that 30-nm
fiber is folded progressively into larger fibers to form large
chromatin fibers
Hierachical helical folding model
64
assumes 30-nm fiber folds into
oriented loops to form mitotic chromosomes
Radical loop model
65
decondensed ~1000-fold compaction
region
Euchromatin
66
~10,000-fold compaction
Heterochromatin
67
Conversion of
Euchromatin to Heterochromatin
Facultative heterochromatin
68
Common form of
heterochromatin
Constitutive heterochromatin
69
DNA sites attached
to proteinaceous structures in interphase nuclei
Matrix attachment regions
70
– beads that appear at meiosis stage in
which chromosomes resemble series of beads on string
Chromomere
71
serves as powerful system for exploring
general principles of chromosome organization and
function
lampbrush
72
Found in the interphase nuclei of larvae tissue of flies
polytene chromosome
73
is the
centromere, which allows one copy of duplicated and
condensed chromosomes (sister chromatids)
Second type of specialized DNA sequence
74
Most species contain single centromere packaged into
heterochromatin
75
are rich in satellite DNA sequences, which
are hundreds of kilobases of repetitive DNA sequence
centromeres
76
the centromere is pulled
toward the pole and the attached chromosome appears to
be dragged along behind it
during anaphase/telophase
77
is critical to centromere function and cells would
fail to recruit kinetochore component in its absence
CENP-A
78
Third type of specialized DNA sequence, which is located
at the end of the chromosome
Telomere
79
short sequences of DNA that have the ability to move to
new locations in the genome and to make additional
copies of themselves
noncoding interspersed transposons
80
repeating DNA sequences may be 15 to 100 bp long
and are found within and between genes
o dispersed throughout the genome
o referred as minisatellites
o basis for DNA fingerprinting
VNTR
81
o consists of di-,tri-, tetra- and pentanucleotide
o known as microsatellites
STR
82
— highly repetitive DNA consisting
of short sequences repeated many times
satellite DNA
83
probably involved in
posttranscriptional gene regulation through the action of
RNA=induced silencing complex (RISC)
satDNA derived siRNAs
84
appear to turn over rapidly, but can be
strongly influenced by positive selection
microRNAs
85
conveniently thought of as dead genes
that play no functional roles; DNA sequences representing
evolutionary vestiges of duplicated copies of genes that
have undergone significant mutational alteration
pseudogenes
86
– generally maternally inherited, although
some plants show biparental inheritance
chloroplasts
87
substitution mutation that does
not change the amino acid sequence of the polypeptide
product, silent mutation
synonymous mutation
88
mutation that does alter the
amino acid sequence of the polypeptide product,
missense codon or a nonsense codon
nonsynonymous mutation
89
– distilled to the concept of accumulation
of substitutions, through time yielding a stable rate from
which we can estimate lineage divergence
molecular clock
90
difference between two genes, the percent
at which the nucleotides are differen
divergence
