Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Bio Exam II

Human Genetics

intro - study of inherited variance in humans - difficulties in studying human genetics (few offspring, long gen. times, cant experiment)
How to study human genetics - pop. studies of large extended families - analyze matings that already occurred - medical attention to human genetic diseases
Use DNA Sequencing DNA sequencing- many generations, extended relatives= genetic basis
Pedigree Analysis - pedigree: family tree/ shows inheritance patterns over several gen. - determine inheritance patterns over several gen. - determine inheritance patterns "based in prevalence & distribution of trait"; used by genetic counselors
Recessively Inherited Disorders - autosomal recessive - Dom. Allele makes enough proteins
Everybody Carries Something - most human genetic disorders are single- locus autosomal recessive traits
2 Outcomes - cell destroyed immediately/ cells clump together
Sickle Cell Heterozygotes - normal & above normal hemoglobin - no phenotypic diff. usually in human homozygotes & heterozygotes
Sickle Cell & Malaria Resistance - malaria: intracellular parasite of RBC's - heterozygotes resistant - sickle- cell allele favored in regions w/ malaria
Dominant Inherited Disorders - Autosomal Dominant: rare; only one defective allele required ex. Achondroplasia: dwarfism; dom. allele
Human Traits w/ non- mendelian inheritance - changes to chromosome # - difference in # of chromosome can cause disease - typical state: disomy (2 copies of eacg chromosome)
Aneuploidy - abnormal # of a partial chromosome (extra or missing copy)
Trisomy - having 3 of a chromosome - 2n+1
Monosomy - lacking 1 member of a pair of chromosomes - 2n-1
Nondisjunction - all abnormalities in chromosome # due to nondisjunction; chromosomes aren't pulled apart properly
Aneuploidy Viability - in humans, monosomes for all autosomes inviable - most trisomies also inviable - estimated that over 50% of pregnancies end by 8 weeks
Trisomy 21 - down syndrome; named after Langdon Down - extra 21st chromosome, complete or partial - frequency increases w/ maternal age
Symptoms of Trisomy 21 - abnormalities of face, hands, tongue, eyelids -slow physical &mental development -short structure - prone to heart malformations, respiratory disease, leukemia
Aneuploidy of sex chromosome - diff. # of sex chromosomes relatively common - many sex chromosome aneuploidies are viable but infertile
Turner Syndrome- XO - 44 autosome 1X chromosomes - "XO" or "45, XO" - Common symptoms: short stature, webbed neck, sterile, no barr bodies
Klinefelter Syndrome- XXY (XXY or 47,XXY) - 44 autosomes 1 X chromosomes, 24 - no specific phenotype - usually fertile (don't transmit extra Y)
Changes to Chromosome Structure - errors in meiosis, radiation, other mutagens
4 Types deletion, duplication, inversion (backwards), translocation ex. Philadelphia chromosomes: translocation: splits a gene, high change of leukemia
Genomic Imprinting - variation in phenotype dependent on parent- specific expression of each allele - occurs during gamete formation
Genomic Imprinting pt.2 - sperm & egg imprinted differently - maternal & paternal copies expressed at diff. levels - often involves DNA methylation= 1 allele silenced= 1 allele expressed
Genetic Testing and Counseling - cancer diagnosis= better change of prevention or alleviation
Fetal testing & Genetic tests done before birth methods - amniocentesis - Chronic villus sampling (CVS) - non-invasive parental screening/testing
Amniocentesis - takes weeks to grow before taking sample
CVS - several hours; takes rapidly growing cells
Newborn Screening - some genetic disorders detected @ birth
Phenylketonuria (PKU) - every newborn tested @ birth in us - normally: phenylalanine= tyrosine - PKU: phenylalanine = phenylketones (toxic) - phenylketones accumulate= damage to nervous system= mental impairment
Managing PKU done eat PKU (anything with amino acids in it)
Created by: tennadeleta.