Malfunctions of the Cell Cycle Flashcards
Meiosis is significant in terms of ?
Evolution
Means that there are individuals that has better chances of survival in a changing environment that ensures species continuity
Genetic Diversity
Meiosis aids in the repairs of?
Genetic defects
Cell division is responsible for the ____ of the body organs
Development
Happens when the cells are worn out or damaged
Cell division
What are the significance of Mitosis
Cell division
Stem cells therapy
Prevention of Cancer
Neurodegeneration
Agriculture
Medicine
Geneticists uses _____ to identify chromosomal aberrations
Karyogram
Process for using Karyogram
- Collects a person’s cells (WBC) from a blood sample
- LAB: stimulates the isolated cells (for actively dividing)
- Applies chemical colchicine to cells to arrest condensed chromosomes in metaphase
- Induce swelling (in cells) w/ hypotonic solution —> chromosomes spreading out
- Preserve sample
What is the chemical used in karyogram
Colchicine
Error in chromosome number
Involves loss or addition or entire chromosome
Aneuploidy
Aneuploidy is caused by?
Nondisjunction
(distribution are not equal)
Losing one chromosome
Monosomy (2n-1)
Gaining an extraneous chromosome
Trisomy (2n+1)
Occurs when homologous chromosome pairs/ sister chromatids fail to separate during meiosis
Nondisjunction
Misaligned or incomplete synapsis, or a spindle apparatus dysfunction that facilitates chromosome migration, can cause _____
Nondisjunction
The risk of nondisjunction
occurring increases with the _____ age.
parents’s
When can nondisjunction occur?
During either meiosis I or II
If homologous chromosomes fail to separate during meiosis I, the result is ________ that lack that particular chromosome and two gametes with two chromosome copies.
two gametes
If sister chromatids fail to separate during meiosis II, the result is ______ that lacks that chromosome, two normal gametes with
one chromosome copy, and one gamete with two chromosome copies.
one gamete
Examples of Autosomal Nondisjunction
Down’ Syndrome
Patau Syndrome
Edward Syndrome
Short stature and stunted digits, facial distinctions that include a broad skull and large tongue, and significant developmental delays characterize individuals with this
inherited disorder
Down’ Syndrome
We can correlate the incidence of Down syndrome with ______
maternal age
TRUE OR FALSE?
Younger women are more likely to become pregnant with fetuses carrying the trisomy 21
genotype
FALSE. Older women
What syndrome has extra copy in chromosome 21? (Trisomy 21)
Down’ Syndrome
Sex Chromosome Nondisjunction examples
Klinefelter Syndrome
Jacob’s yndrome
Trisomy X
Turner’s Syndrome
o has 47 chromosomes (+1)
o XXY
o Poor male sex organ development; subfertility enlarged breast, little to no sperms, no body hair, and broader hips
Klinefelter Syndrome
Can be also called as XYY Syndrome
Jacob’s Syndrome
o Affects male children
o Can have children
o Has 47 chromosomes
Jacob’s Syndrome
o No distinct physical features and mostly show behavioral difference
o Increased risk of learning disabilities and delayed development of speech and
language skills.
o can have delayed development of motor skills (such as sitting and walking) or
weak muscle tone (hypotonia).
Jacob’s Syndrome
Another term for trisomy X?
Triple X Syndrome
o 47 chromosomes
o Affects female
o There are three X chromosomes and no Y chromosome
o Seizures or kidney abnormalities occur in about 10% of affected females.
Trisomy X
Another term for Turner’s Syndrome?
Monosomy X
o 45 chromosomes
o No Y chromosomes
o They are genetically female, but they do not mature sexually during puberty.
Turner’s Syndrome
o Web-like neck, fingernails, and toenails that are narrow and turned upward,
slightly smaller than average height at birth, and short fingers and toes.
Turner’s Syndrome
Double, duplicate only a segment of chromosome
- Deletion
- Translocation
- Inversion
Chromosomal Alteration
Examples of Chromosomal Alterations (Structural Changes)
Duplication
Deletion
Translocation
Happens if the fragment joins the homologous chromosome, then that region is repeated
Duplication
Pallister Killian syndrome, where part of the #12 chromosome is duplicated.
Duplication
where a portion or part of the chromosome is lost during the cell division and the result is mostly lethal (Cri du Chat)
Deletion
where a small part of the chromosome is moved to another chromosome.
Translocation
The number of chromosomes is not changed but there are changes in phenotypic
expression since genes are placed in other locations.
Translocation
If there is an exchange with the parts of a chromosome, it is called ________ but if there is no exchange, just a transfer then it is ___________.
reciprocal translocation
non-reciprocal translocation
______ involving human chromosomes are linked to a number of disorders, including mental retardation, infertility, and cancer.
Translocation
