17 Questions
What is the purpose of ultrasonography in prenatal screening?
To carry out at specific weeks to detect abnormalities or disorders
What does amniocentesis involve?
Inserting a needle through the mother's abdominal wall to withdraw an amniotic fluid sample
What is the purpose of syncytiotrophoblast biopsy?
To be used as a component of screening for fetus trisomy
At what stage of gestation can anencephaly be detected?
Week 18-20
What is the risk of miscarriage associated with chorionic villus sampling performed at 10-12 weeks?
0.5-1%
What does maternal serum analysis measure during genetic screening?
Decrease in factor associated with Edward syndrome (Trisomy 18)
Which type of mutation results in changes to the nucleotide sequence of DNA in somatic cells?
Point mutation
What type of mutation occurs when a base substitution changes an amino acid in a protein?
Nonsense mutation
What is the effect of a deletion or insertion of one or more nucleotides that does not result in a multiple of 3?
Change in splicing sequence
Which type of mutation causes a 'sense' codon to become a 'coding' codon?
Frame shift mutation
What is the effect of reciprocal translocation between non-homologous chromosomes?
Formation of a single, large chromosome with a single centromere
What causes an acrocentric chromosome to fuse into a single, large chromosome with a single centromere?
Robertsonian translocation
What is the effect of duplication of a segment of chromosomes during DNA replication?
Alteration in gene expression level
What is the effect of an intrinsic mutation between non-homologous chromosomes?
Mutational re-arrangement within a chromosome
What is the effect of radiation or chemical exposure on genetic material?
Base substitution and breakage of DNA structure
What is the cause of triploidy (3n) leading to miscarriage in most cases?
Polyploidy
What is the effect of inversion leading to decreased binding of transcription factors and RNA polymerase to the promoter?
Decreased gene expression
Test your knowledge on prenatal screening and ultrasonography which can help detect particular disorders and predispositions to diseases in fetuses. Learn about the timing of different ultrasound scans and their significance in detecting abnormalities.
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