KARYOTYPING

Question 1

the number and appearance of chromosomes in the nucleus of a eukaryotic cell.

also used for the complete set of chromosomes in a species, or an individual organism.

Answer 1

Karyotype

Question 2

Karyotype analyzes

Answer 2

~Sex chromosomes content
~Presence or absence of individual chromosomes
~Nature or extent of chromosomal aberrations

Question 3

Karyotyping Analysis
specimen for adult:

Answer 3

blood (WBC), bone marrow, or skin sample

Question 4

Karyotyping Analysis
specimen for an unborn child:

Answer 4

amniotic fluid (contains stray cells) or extra-embryonic cells (from the chorionic villi)

Question 5

Karyotyping Procedure:
plant-derived chemicals that stimulate mitosis

Answer 5

Lectins

Question 6

Karyotyping Procedure:
Drug used to stop or arrest the mitotic process at metaphase. It arrests the action of spindle fiber microtubules; hence ceasing the mitotic process

Answer 6

Colchicine

Question 7

Key characteristics used to distinguish chromosomes from one another:

Answer 7

~The length of the arms of the chromosome
~Shape
~General appearance of the chromosome.

Question 8

Variations in Chromosome number:
a chromosome number that is a multiple of the normal haploid set.

Answer 8

Polyploidy

Question 9

Variations in Chromosome number:
It is a deviation of an abnormal number of chromosomes in which an additional chromosome pair is added to a particular chromosome (48 chromosomes)

Answer 9

Tetrasomy

Question 10

Variations in Chromosome number:
a chromosomal number that varies by something less than a set

Answer 10

Aneuploidy

Question 11

Variations in Chromosome number:
having only one member of a homologous pair. (e.g., Turner syndrome)
~45 chromosomes
~one chromosome is missing

Answer 11

Monosomy

Question 12

Variations in Chromosome number:
having three copies of a single chromosome. (e.g., Down syndrome)
~most common aneuploidy

Answer 12

Trisomy

Question 13

Major cause of reproductive failure is

Answer 13

Aneuploidy

Question 14

caused of Polyploidy: (EEE)

Answer 14

Errors in meiosis
Events after fertilization
Errors in mitosis

Question 15

Type of Polyploidy
~Three sets of chromosomes
~Most common form of polyploidy
~Probably due to polyspermy
~15-18% of all spontaneous abortions
~Approximately 75% have two sets of paternal chromosomes
~1% conceptions are triploid but 99% die before birth
due to:
~egg is fertilized by a sperm with a double set of chromosomes
~the egg is fertilized by two sperms
~the egg producing cells fail to divide properly and so the mature egg contains double set of chromosomes.

Answer 15

Triploidy

Question 16

Type of Polyploidy:
~Four sets of chromosomes (two extra chromosome set are present)
~5% of all spontaneous abortions
~Extremely uncommon in live births
~May result from failure of cytokinesis in the first mitotic division.
~Life threatening
(92 chromosomes)

Answer 16

Tetraploidy

Question 17

___ is the failure of homologs or sister chromatids chromosomes to separate in meiosis or mitosis

Answer 17

Nondisjunction

Question 18

Autosomal Monosomy or Autosomal Trisomy:
~Lethal condition
~Rarely seen in spontaneous abortions and live births
~Majority are lost early in development

Answer 18

Autosomal Monosomy

Question 19

Autosomal Monosomy or Autosomal Trisomy:
~Most are lethal
~Varies by chromosome (e.g., Trisomy 13, 18, 21)

Answer 19

Autosomal Trisomy

Question 20

Autosomal Trisomy:
~Affected infants small at birth grow slowly and are mentally retarded
~Malformation of heart, hands and feet
~80% are female
~Advance maternal age is a risk factor

Answer 20

Trisomy 18

Question 21

Other name for Trisomy 18

Answer 21

Edwards Syndrome

Question 22

Autosomal Trisomy:
~Lethal: mean survival time is at least 1 month
~Facial malformations, eye defects, extra fingers or toes, and large protruding heels
~Severe malformations of brain, nervous system, and heart
~Parental age only known risk factor

Answer 22

Trisomy 13

Question 23

Other name for Trisomy 13

Answer 23

Patau Syndrome

Question 24

Autosomal Trisomy:
~First chromosomal abnormality discovered in humans (1959)
~Leading cause of mental retardation and heart defects in US
~Wide flat skulls, skin folds in the corner of the eyes, spots on the irises, and thick-furrowed tongues.
~40% congenital heart defects.

Answer 24

Trisomy 21

Question 25

Other name for Trisomy 21

Answer 25

Down Syndrome

Question 26

Risks for autosomal trisomy (2)

Answer 26

~Advanced maternal age
~Risk increased rapidly after 35 years of age

Question 27

Autosomal Trisomy:
~Features do not develop until after puberty
~Affected individuals are male with low fertility and may have mental dysfunction
~60% due to maternal nondisjunction
~Other forms XXYY, XXXY and XXXXY

Answer 27

Klinefelter’s Syndrome (XXY)

Question 28

Autosomal Monosomy
~Females, short, wide chest, rudimentary ovaries, and abnormal sexual development
~Puffiness of hands and feet
~Abnormalities of the aorta
~No mental dysfunction
~Single X chromosome (lethal)

Answer 28

Turner Syndrome (X)

Question 29

Autosomal Trisomy:
~Above average in height
~No established link with possible antisocial behavior

Answer 29

Jacob Syndrome (XYY)

Question 30

inactive X chromosome in a female somatic cell

Answer 30

Barr Body

Question 31

Cells Used for Chromosomal Analysis (STRACAL)

Answer 31

Skin cells
Tumor cells
Rare fetal cells from maternal blood
Any cell with a nucleus
Chorionic villi
Amniotic cells
Lymphocytes

Question 32

Most common type of banding

Answer 32

G-banding

Question 33

Types of banding:
Obtained with Giemsa stain following digestion of chromosomes with trypsin.
~The dark regions tend to be heterochromatic, late-replicating and AT rich
~The light regions tend to be euchromatic, early replicating and GC rich

Answer 33

G-banding

Question 34

Types of banding:
the reversed of G-banding.
~The dark regions are euchromatic (guanine-cytosine rich regions)
~The bright/light regions are heterochromatic (thymine-adenine rich regions)

Answer 34

R-banding

Question 35

Types of banding:
Giemsa binds to consecutive heterochromatin, so its stains centromeres.

Answer 35

C-banding

Question 36

Types of banding:
a fluorescent pattern obtained using quinacrine for staining. The pattern of bands is very similar to that seen on G-banding

Answer 36

Q-banding

Question 37

Types of banding:
Visualize telomeres

Answer 37

T-banding

Question 38

More specific than Giemsa stain

Answer 38

Spectral Karyotyping

Question 39

a molecular cytogenetic technique used to simultaneously visualize all the pairs of chromosomes in an organism in different colors.

this technique is used to identify structural chromosome aberrations in cancer cells and other disease conditions when Giemsa banding or other techniques are not accurate enough

(e.g., FISH typing)

Answer 39

Spectral Karyotyping

Question 40

a technique used to quantify the DNA copy number on a genomic scale. Short sequences of DNA from specific loci all over the genome are isolated and enumerated.

This method is also known as virtual karyotyping

(e.g., PCR)

Answer 40

Digital Karyotyping

Question 41

the number of complete sets of chromosomes in a cell

Answer 41

Ploidy

Question 42

Where one sex is diploid, and the other haploid. It is a common arrangement in the Hymenoptera, and in some other groups.

Answer 42

Haplo-diploidy

Question 43

A process by which chromosomes replicate without the division of the cell nucleus, resulting in a polyploidy nucleus. Also called endomitosis.

Answer 43

Endopolyploidy

Question 44

Translocation mutation commonly associated with chronic myelogenous leukemia and less often with acute lymphoblastic leukemia.

Answer 44

Philadelphia chromosome