karyotype lab

what is a karyotype

a photo of an organisms chromosome set

how are karyotypes used

for evolutionary studies, pre-natal screenings, other medical diagnoses

how does the karyotype of a male differ from a female

female has two x chromosomes, while male has one x chromosome and one y chromosome

what are the 5 main steps of the procedure used to make a karyotype

1) cell sample taken, chemicals added

2) incubated for 3 days

3) more chemicals, stopped in metaphase

4) cells transferred

5) solution observed

what is deletion

segment of chromosome is missing, instructions not there on how to make or do something

what is a inversion

• segment of a chromosome shuffled around

• person will not show effects

• offspring will have problems

what is translocation

• segments of non-homologous chromosomes exchange locations

• person will show no effects

• offspring will have problems

what is nondisjunction

extra or missing chromosome

what are fragile sites

specific heritable point on a chromosome that tends to form a gap/constriction

what criteria is used to identify each chromosome by number

• size

• banding pattern

• centromere location

what two things is the process of karyotyping used for

finding diseases and abnormalities

what are bands

area of chromosome that can be stained, each chromosome has a distinct pattern of this

what is a centromere

where two chromatids are held together

what is a chromotid

either member of a joined chromosome

what is a gene

threadlike structure of DNA in cell nuclues that carries genes

what is a gene

basic unit of a inheritence

what is a syndrome

group of symptoms that characterize a particular disorder

what is a trisomy

presence of three of a chromosome rather than two

what is P and Q arms of a chromosome

shorter arm is P, longer arm is Q. together are the two segments divided by centromere

what is edward syndrome

• trisomy 18

• elongated skull

• hair lip

• cleft plate

• rocker-bottom feet

what is jacob syndrome

• 47 chromosome

• XXY

• males normal

• difference in EEG pattern

what is patau syndrome

• trisomy 13

• microcephaly

• microphthalmia

• most die after birth

what is turner syndrome

• 45 chromosomes

• XO

• phenotypically female

• streak ovaries

• no ova produced

• do not menstruate

• <46 survive

what is prader-willi syndrome

• deletion of Q arm on 15

• small head

• retarded

• bizarre behavior

what is down syndrome (trisomy)

• trisomy 21

• epicanthic folds of eyelid

• protruding tongue

• small and low-set ears

• retardation

what is klinefelter syndrome

• 47 chromosomes

• XXY

• low levels of testosterone

• enlarged breasts

• small testicles

• phenotypically males

what is cri du chat syndrome

• deletion of part of P arm and chromosome 5

• improperly developed larynx

• cat like cry until age 2

• IQ under 20

what is 18-Q deletion syndrome

• deletion of Q arm and chromosome 18

• 13 ribs

• IQ under 30

what is translocation down syndrome

• extra 21st chromosome attaches to chromosome 14

• epicanthic folds of eyelids

• simian crease in palms

• mental retardation

why is incidence of survivable genetic disorders so rare

deletion of a chromosome removes many essential genes

why is the incidence of trisomy of larger chromosome rarer than smaller chromosomes

larger the chromosome, the more genes it involved

what is the relationship between severity of symptoms and size of chromosome involved

larger the chromosomes have more genes. Thus symptoms are more severe if more genes are involved

what is the most common symptoms of genetic symptoms after looking at them all

abnormal physical development