karotype
A picture of all the chromosomes in a cell arranged in pairs
Pedigree
A chart or "family tree" that tracks which members of a family have a particular trait
affected pedigree
is shaded/colored
Carrier in pedigree
Half-Shade
Unaffected pedigree
unshaded
multifactorial
determined by many factors, both genetic and environmental, collectively influence phenotype
Diabetes, Dementia, High Blood Pressure are types of what disorders
multifactorial disorders
single gene
change or mutation in one gene
single gene recessive trait examples
sickle cell and cystic fibrosis
single gene dominant trati examples
dwarfism and huntington's disease
sex-linked trait
passed on the sex chromosomes (the X or the Y)
why do males more affected by sex linked trait diseases?
because women have 2 X chromosomes and only need one to function while men have only 1 X-chromosome
mitochondrial disorders
Leber's heditatry optic nueropathy
sex linked trait examples
colorblindness, duchenne muscular dystrophy and hemophilia
what disorder is only passed from mother to child?
mitochondrial disorders
chromosomal disorders
not having enough or having extra chromosomes
what are some examples of chromosomal disorders?
Down Syndrome, Turner's Syndrome, Klinefelter's Syndrome
how are chromosomal disorders revealed?
karotypes
what do we use to find out abt diseases?
genetic screening
Carrier Screening
test that is typically done on adult couples who are considering having children and want to determine if those children could inherit any diseases.
how is carrier screening done?
blood sample is drawn, DNA is extracted and amplified using PCR, and then DNA goes under testing for diseases.
Preimplantation Genetic Diagnosis (PGD)
often used by people with known autosomal dominant or sex-linked conditions that they do not want to pass on to their children
How is PGD done?
eggs are fertilized in a vitro dish and after they are developed, a single cell from each embryo is removed, amplified, and tested for the trait the parents dont want to pass
Fetal Screening/Prenatal diagnosis is performed when?
when fetuses are inside the mommy
amniocentesis
needle puncture of the amniotic sac to withdraw amniotic fluid for analysis
When is amniocentesis performed?
14-20 weeks
chorionic villus sampling
the examination of cells retrieved from the placenta
what are risks of getting amniocentesis chorionic villus sampling?
miscarriage
Newborn screening
the testing of infants shortly after birth
how do we do newborn screening?
A small sample of blood is taken from the baby, and DNA is isolated from it for testing purposes
Newborn screening is used for what?
for inherited diseases if the parents choose not to implement measures that complete this testing while the baby is still in utero
What does PCR stand for
polymerase chain reaction
What do we use for PCR?
taq polymerse, DNA primers, and DNA nucleotides
what is the first step of PCR
denaturation
what is denaturation
high temperature breaks hydrogen bonds that hold the double stranded DNA together.
Second step of PCR
annealing
what is annealing
dna primers are added to the dna mixture and dna primers are binding to dna
why is dna primer present?
so taht the DNA is reading for copying
what is the 3rd step of PCR
extension
what is extension?
taq polymerse is used to copy bacterial dna before bacterial cells divide.
what is genotype
genetic code for traits that we possess
testing for traits in the lab can be done with what?
gel electrophoresis
what does centrifugation do?
separates DNA from cell waste
why are restriction enzymes used for gel electrophoresis for gene testing?
so that different versions of the gene, "bad" or "good", can be distinguished
what does the end result of gel electrophoresis determine?
reveals the genotype of the individual being tested
what trimester is critical during pregnancy?
the first
what is gene therapy?
the transplantation of normal genes into cells in place of missing or defective ones in order to correct genetic disorders.
what are vectors
viruses
type of vectors?
retroviruses, adenoviruses, adeno-associated viruses, herpes simplex viruses, liposomes, and naked DNA.
purpose of vectors?
providing unaffected genes to people carrying specific genes
sperm sorting
a method of separating sperm that carry Y chromosomes from sperm that carry X chromosomes; you can choose gender of the baby
plasmid and liposome
-can be any size -dna -dont generate immune response -dont do genome integration -less efficient, therefore result in low protein levels
Herpes virus
-dna -double stranded -only infects nervous cells -creates immune response
adenovirus
-dna -double stranded -can enter differing cell types -creates immune response -results in high levels of protein
Retrovirus
-rna -only infects dividing cells -creates immune response -integrate with genes randomly
Adeno-associated virus
-dna -single stranded -can enter different amount of cells -create permanent genome integration
Lentivirus
-rna -can enter different types of cells -integrates with genes randomly
Cystic Firbrosis
an inherited disease that affects glands, causing buildup of mucus, which blocks the ducts
cystic fibrosis means a lack of what?
CFTR gene which controls salt and balance of water in the body
what vector should be used for cystic fibrosis?
adeno-associated
which screening method removes cells from the placenta?
chronic villus sampling
which method removes amniotic fluid for testing?
amniocentesis
which screening method is the least risky/invasive
ultrasound
a single cell is taken from an embryo and tested for genetic abnormalities. what method was used?
pre-implantation genetic diagnosis (PGD)
which disorder is caused by an extra chromosome
down syndrome
which disorder is considered to be multifactorial
alzeheimer’s disease
what is not a step in PCR
sequencing
what causes DNA fragments to separate in each lane of an agase gel?
electrical current
dna fragments separate during gel electrophoresis according to their…
size
what are the correct pcr steps
denaturation, annealing, extension
what type of genetic disorder is the best target for gene therapy?
single gene mutation
which is not an important consideration when choosing a gene therapy vector
whether its RNA or DNA
which 2 techniques can be used to select the sex of the baby
sperm sortinga and PGD
what kind of genetic disorder is down syndrome
chromosomal
what kind of genetic disorder is cystic fibrosis
single gene recessive
what pre-natal screening/testing can be done earlier during pregancy
CVS
which gene therapy vector carries single stranded rna
retrovirus
what gene vector would be ideal for inserting a gene that was 18500 base pairs long
herpes-simplex virus
what kind of genetic disorder can be detected with a SNP analysis and gel electrophoresis?
single gene
what genetic disorder can be detected with a karotype
chromosomal
which occur when gametes are fertilized in a dish in the lab which result in a zygote
IVF