Cytogenetics Flashcards
What is cytogenetics?
The study of chromosomes and their structure, inheritance, and abnormalities
Which arm of the chromosome is the long arm? Which is the short arm?
Long= q; short= p
During which stage of mitosis are chromosomes best visualized?
Metaphase
Which class of chromosome structure has the centromere directly in the center of the chromosome?
Metacentric
Which human chromosomes are telocentric?
None
What class of chromosome structure has the centromere very near the end of the chromosome?
Acrocentric
What technique enables the identification of individual chromosomes by producing characteristic light and dark bands?
G-banding
What are the two types of chromatin visualized via G-banding?
Dark staining= Heterochromatin; Light gray or white= euchromatin
What is the name of the lab techniqu in which fluorescently labeled fragment of cloned DNA (probe) is allowed to pair with its complementary sequence on the chromosome directly on the microscope slide
Fluorescence in situ hybridization
What is polyploidy?
Any abnormal multiple of the haploid chromosome number
What is aneuploidy?
Any number of chromosomes that is not diploid
What is the most common cause of aneuploidy?
Nondisjunction
What is the most common cause of triploidy?
Simultaneous fertilization of one egg by two sperm
What is the chromosomal basis of Down Syndrome?
Trisomy 21
What is the most common trisomy?
Trisomy 21