(M) Abnormalities in Chromosome (2) Flashcards
Numerical Abnormalities
with extra sets of chromosomes; caused by fertilization of an egg by >1 or 2 sperm; not compatible with life
Polyploidy
di
ck
T or F. Numerical abnormalities ONLY results from loss of whole chromosome.
F (gain and loss)
T or F. Triploidy is NOT compatible with life.
T
Numerical Abnormality
state of having 2 or more genetically
different cell lines
Mixoploidy
T or F. Polyploidy are acquired or somatic type of chromosomal abnormalities based on chromosomal constituents
F (mixoploidy)
these are those that arise from
two different zygotes
chimera
T or F. Infusion of cells from a twin to another is the same description of Chimera.
T
Type of Aneuploidy: state of having a missing a pair of homologs occurring during the preimplementation stage; lethal
Nullisomy
Types of Aneuploidy: one chromosome missing; occurs during embryonic stage; lethal and abort in 99% of cases
Monosomy
Among this are exception to monosomy except:
A. Monosomy 21
B. Monosomy X
C. Turner Syndrome
D. (45, X)
A
T or F. Trisomy occurs during embryonic (3-8 weeks) or fetal development (9-36 weeks) stage
T
T or F. Trisomy 21 is lethal and may survive or reach 40 y/o or more.
T
What phase in the interphase affects both chromatids?
G1
What phase of the cell cycle affects one chromatid?
G2
Ways to repair that will stabilize your chromosome
joining the two ends or capping end with telomere
What prevent entry of cells with unrepaired chromosome breaks to enter mitosis and it delays mitosis and allows repair of the damaged chromosomes?
Checkpoints
Failure of repair leads to?
Apoptosis
An incorrectly repaired chromosome will lead to?
structural abnormalities
T or F. Cell cycle can halt to undergo repair but an incorrectly repaired chromosome may still be able to pass checkpoints.
T
the point where the cells is committed to advance further into the cell cycle without requiring anymore broad signal that initiated cell division.
restriction point
What phase of the cell cycle checks for DNA damage, adequacy of cell size, and presence of broad signals for cell proliferation
G1 restriction point
T or F. In the S chromosome, there’s a chromosomal duplication and growth in mass
F (duplication lang)
What phase of the cell cycle checks for damaged or unduplicated DNA?
G2 restriction point
Forms
healed by adding telomere, if near the telomere
single break (terminal deletion)
Forms
Balance Translocation
Single break (two chromosomes with a single break they can exchange their broken segments)
Forms
ring chromosome formation, duplication, interstitial deletion, inversion, translocation
no. of breaks
Two or three breaks
T or F. If 3 breaks, you can have ring chromosome formation because the ends can fuse because they are very sticky, although you can have deletion there; you can also have insterstitial deletion, inversion
F (2 breaks)
T or F. If at least 3 breaks, you can have duplication, some breaks in the arms that are being duplicated and other break in the other arm where the duplication will transfer.
T
Forms
formed when two telomeres are lost; ends become sticky and adhere/fuse to form a ring
Ring Chromosome
Form
more likely due to loss of gametes or genes
in the telomeric regions of the chromosome
than the ring formation itself
Ring Chromosome
T or F. Ring formation can go to the cell cycle because it has been repaired but it is also unstable
T
Form
refers to extra chromosomal segment within the same homologous or another non-homologous chromosome
Duplication
T or F. Inversion can also occur between two
homologous chromosome or non-
homologous chromosome
F (duplication)
From
two breaks - broken portion turned
upside down - reattached
inversion
inversion of a segment of the p or q arm and does not include the centromere
Paracentric inversion
inversion
breaks occur in both short and long arms and includes the centromere in the inverted segment
Pericentric inversion
T or F. In inversion, there’s loss of genetic materials.
F
Form
loss of a segment of a chromosome
Deletion
T or F . Terminal end is more common than interstitial deletion.
T
Form
2 breaks between the centromere and telomere à loss à fusion of broken ends to the more proximal segment
Insterstitial deletion
T or F. Deletion involves a loss of genetic material regardless of the type of deletion.
T
Translocation
involves exchange of genetic materials of non-homologous chromosomes
reciprocal or balanced
TOF. Robertsonnian translocation have one break from the chromosome, one break from the other and then exchange of segment of the two chromosomes.
F (balanced)
form
involves acrocentric chromosomes which have short p arms called satellites
Robertsonian Translocation
TOF. A person cant function even if satellites are lost
F
TOF. Miscarriages or spontaneous abortion may also occur in balanced Translocation.
T
T or F. In centric fusion there is a loss of genetic materials and formation of 2 long arms.
T
Centric fusion except:
A. No clinical symptoms
B. Lost of mRNA
C. Lost of centromere
D. Both B and C
E. All of the Above
E
T or F. In acrocentric chromosomes, there’s no clincal symptoms but have increased risk of infertility, spontaneous abortions or chromosomally unbalanced offsprings for carriers
T
Form
occurs when the exchange of chromosome material is unequal resulting in loss or gain of genes.
Nonreciprocal or unbalanced
translocation
T or F. Nonreciprocal or unbalanced
translocation does not also cause significant clinical outcomes.
F
Chromosomes with 2 identical arms is possible due to?
transverse division (of the centromere or U-type exchange between sister chromatids along the centromere under iso)
Try to explain what happened
terminal deletion of 1 healed by the addition of telomere
Describe
An unequal crossover or unequal sister chromatid exchange; instertitial deletion
Identify abnormality
Paracentric inv.
Identify abnormality
Pericentric inversion
Final Chromosomes?
1 Dicentric
Chromosome and 1 Acentric
Chromosome (left) and Stable reciprocal translocation (right)
EXCHANGE OF CENTRIC AND ACENTRIC
FRAGMENTS leads to?
1 Dicentric
Chromosome and 1 Acentric
Chromosome.
