Chapter 24 COnnect

which method can be used at the DNA level to detect the presence of a specific mutation in a disease causing allele

DNA microarray analysis

Identical twins share a genetic disease more often than fraternal twins:

TRUE

Genetic testing is used to determine whether a(n)_____ has a disease causing gene, while genetic screening is used to determine how frequently the gene is found in a(n)______.

individual; population

a situation where a disease may be caused by mutations in two or more different genes is called

locus heterogeneity

A prion is a disease-causing agent composed of

protein alone

select the human disorders that are inherited in an autosomal recessive fashion

sickle cell disease phenylketonuria cystic fibrosis

when a defect in a single gene causes a human disease, the mutant gene often follows

simple mendelian inheritance patterns

To study the distribution of disease-causing genes, genetic ___ refers to determining if an individual carrier the faulty gene while genetic _____ relates to assessing the presence of the gene throughout the population

testing, screening

approximately how many human disease have a genetic basis

thousands

consider the children of II-6 and II-7 in the accompanying pedigree for a family affected by Tay-Sachs disease. what is one genotype that could have been produced by these two parents but was not observed

unaffected homozygote

how can abnormal forms of the prion protein arise within an individual

- a person may have inherited an allele that causes their normal prion protein to convert to an abnormal one at a low rate - a person can be infected by eating meat from an animal with the disease

in the accompanying pedigree, a filled symbol indicates an individual with Huntington disease while a clear symbol shows an unaffected individual. which of these following characteristics of inheritance can be observed for this family

- an affected individual has at least one affected parent - the trait occurs in both males and females

what is the inheritance pattern when a trait occurs with the same frequency in both sexes and an affected offspring can have two unaffected parents

Autosomal recessive

which methods can be used at the DNA level to test for specific mutations related to the genetic disease

DNA sequencing FISH fluorescence in situ hybridization DNA microarray analysis

Twins that share about 50% of their genetic material are called _____ twins.

Dizygotic

rett syndrome which is inherited dominant manner is caused by a mutation in the gene for

MECP2.

embryos produced by in vitro fertilization can undergo genetic testing by

Preimplantation genetic diagnosis

what is the inheritance pattern for the trait that more commonly affects males than females which will occur in about 50% of the sons to be born to unaffected daughter of an affected male

X linked recessive

in one study, autism showed 60% concordance for monozygotic twins and 0% concordance for dizygotic twins. this demonstrates that autism is

a genetic disease

chorionic villus sampling is a produce for

a procedure in which a small sample of tissue is removed from the placenta.

The abnormal form of a prion protein causes a neurodegenerative disease by:

catalyzing the conversion of the normal protein form to the abnormal protein fo

true or false: Dizygotic twins share a genetic disease more frequently than monozygotic twins

false

a dominant genetic disorder can be caused by a ____ mutation where the product of an altered gene gains a new or abnormal function

gain of fucntion

select human disorders inherited in an autosomal dominant fashion

huntington's disease Marfan syndrome aniridia

which statements is true of X linked dominant disorders such as Rett syndrome and Aicardi syndrome

males die at an early stage of development

Twins that are genetically identical to each other are called

monozygotic

Suppose a disease causing allele shows autosomal recessive inheritance. How would a carrier of this disease-causing allele be identified?

Carriers often show reduced activity for the enzyme encoded by the allele.

select human disorders that are inherited by an X linked dominant manner

- rett syndrome - vitamin D resistant rickets - incontientia pigmenti

which of the following characteristic of inheritance can be observed in the accompanying pedigree of a family affected by Tay- Sachs disease

- an affected offspring can have two unaffected parents - the trait occurs in both males and females - affected individuasl are offspring of heterozygous parents

What is the inheritance pattern for a trait that on average occurs with the same frequency in both sexes and two affected heterozygous individuals have, on average, 25% unaffected offspring?

Autosomal dominant

which type of mutation causes a dominant genetic disorder through the production of an altered protein that works against the action of the normal protein

Dominant-negative

select human disease that are inherited in an X linked recessive fashion

hemophilia duchenne muscular dystrophy Androgen insensitivity syndrome