Karyotypes are prepared from _______ that are in ______
Somatic cells
metaphase
Compensation for the extra unneeded X chromosome is accomplished by:
X-inactivation
The genes found on the Y chromosome:
are responsible for secondary sex characteristics
Karyotype
Chromosomes arranged in pairs from largest, most metacentric to the smallest most acrocentric
Metacentric
centromere is in the middle of the chromosome
Submetacentric
One chromosome arm is longer than the other
p=_______ arm
short arm
q=____arm
long arm
acrocentric
centromere is at one end
the short arm consists of heterochromatin and nucleolar organzing region
may be variable in size and staining patterns
Primary constriction
the centromere- typicalled associated satellite DNA ( alpha-satellite)
Secondary constriction
Consists of highly repetitive sequences that are either inert or NOR (nuclear organizing region)
stain lighter
Telomere
Functional DNA sequence TTAGGG
prevents chromosomes ends from sticking to each other
Satellite
a genetically inert piece of chromosome usually connected to the short arm of acrocentric chromosome via a secondary constriction , the NOR and highly repetitive DNA sequences
Chromosome bands
Cross striation patterns on chromosomes due to various treatments
reflect underlying DNA sequences and chromosome structure
Cultures from peripheral blood are obtained by transforming_______ from a resting stage to actively dividing cells using__________
T-lymphocytes
phytohemaglutinin
phytohemaglutinin
Brings t-lymphocytes to an actively dividing state
a ____tonic solution is used swell the cells to aid chromosomes in sperading
Hypotonic
Fix is made of:
it is used to:
Methanol and acetic acid
preserves nucleoprotein structure and clears cytoplasm
Q banding
the first banding technique
uses a special fluorescent microscope
G Banding
produces banding patterns after gentle treatment with trypsin followed by staining with Giemsa
C banding
Stains heterochromatin around the centromeres of every chromosome and secondary constrictions of 1, 9 and 16
NOR (silver staining)
Stains nucleolar organizer regions on acrocentric human acrocentric chromosomes
BrdU labeling
Early or late DNA replication patterns when subsituted for thymidine in early or late S period
When substituted for thymidine through two complete cell cycles produces differential staining of sister chromatids and reveals sister-chromatid exchanges (SCEs)