Test 6. (Genetics) Flashcards
amniocentesis
fetal testing technology used to detect chromosomal abnormalities… extracting amniotic fluid and harvesting cells in a lab to later watch dividing cells in a karyotype.
chorionic villi sampling (CVS)
fetal testing technology used to detect any chromosomal abnormalities…tissue from the placenta is extracted and cells once again are karyotypes (this method is much quicker and can be done earlier on in the pregnancy)
at what phase are chromosomes condensed (stop dividing) at?
metaphase of mitosis!
karyotype
image of individual separate chromosomes… used to detect chromosomal abnormalities
aneuploidy
an abnormal number of chromosomes
what causes aneuploidy?
nondisjuction
what are two possible ways nondisjunction can occur?
chromosomes fail to separate at meiosis 1 OR sister chromatids fail to separate at meiosis 2
what would the karyotype of a normal male have?
a x and Y chromosome (y is shorter than x) on the 23 location
what would the karyotype of a normal female have?
two X chromosomes on 23 location
what would a karyotype of a person with Down syndrome (trisomy 21) look like?
three copies of chromosome 21 on 21 location
what would the karyotype of a male with Klinefelter syndrome look like?
3 chromosomes on 23 location of the karyotype (XXY)
what does the turner syndrome for a female look like on a karyotype?
missing an X chromosome on location 23
what is used to make chromosomes more visible under microscopes?
giemsa dye
symptoms of Klinefelter syndrome
abnormally small testes, sterile sperm, female body characteristics (larger breasts)
symptoms of turner syndrome
sterile eggs, poor development of breasts sole known case that is not fatal
