2.4 Flashcards
what did an antenatal screening do
identifies the risk of a disorder so that further tests and prenatal diagnosis can be offered
when dies a dating scam occur
8-14 weeks
what is the reason for dating scan
measuring fetus, determining the due date and stage of pregnancy
what is the timing for an anomaly scan
18-20 weeks
what is the reason for an anomaly scan
look for serious physical abnormalities
why are blood and urine tests done
to monitor concentrations of marker chemicals
what can happen if blood and urine tests are done at the wrong time
a false positive , leading to a misdiagnosis
what happens due to amniocentesis
small amount of fluid from the amniotic sac surrounding the foetus to check for genetic disorders carrioud out between 14 - 16 weeks
what is cvs
cells from placenta are tested from genetic disorders
as early as 8 weeks
give an advantage of amniocentesis
smaller chance of misscariage
advantage to cvs
is done earlier in the pregnancy
what are homologous pairs
two chromosomes that are very similar in size , shape and genetic information, one from the mother and one from the father
what is dominant
alleles that are always expressed
what is a genotype
genetic makeup , made from alleles which determine d gratuité
what is genetics
study of inheritance controlled by genes
what is a phenotype
features resulting from the expression of genes
what is an allele
different forms of the same gene
what does homozygous mean
two alleles of a pair that are the same
what does recessive mean
alleles are only expressed if both alleles are recessive
what is a gene
a section of dna that codes for a particular protein
what does heterozygous mean
two alleles of a pair are different
what does autosomal dominant inheritance mean
any sufferers only require one dominant allele it effects both genders equally
what does autosomal recessive mean
suffered require two recessive alleles to be affected
autosomal incomplete dominance
the dominant allele may not fully express itself
what does sex linked recessive mean
sex chromosomes, carry genes that code for functions
what is pku
disorder meaning people can’t break down phenylalanine causing a build up
what is an example of an autosomal recessive disorder
cystic fibrosis
what is an example of automsomal dominant disorder
huntingtons
what is an example of an incomplete dominant disorder
sickle cell disease
what is a sex linked recessive disorder
haemophilia
