Genetics Ch. 10 & 11

Mutations in ______ cells are transmitted to all future generations.

germ

The ability of DNA polymerase to repair its own nucleotide mismatches is called __________.

proofreading

Mutations are changes in the nucleotide sequence of DNA that ____.

Can be passed onto daughter cells

T/F: Nonsense mutations change termination codons into amino acid codons.

False

Why is it difficult to identify the source of an autosomal recessive mutation in a family pedigree?

Heterozygous carriers can remain undetected for generations.

Supertasters for the chemical PTC are ____ for the trait.

Homozygous dominant

A mutation in the Factor VIII gene − required for blood clotting − changes a CGT codon to CAT, and changes the amino acid from arginine to histidine. This is an example of a ________ mutation.

Missense

sense mutation

Mutations that change a termination codon into one that codes for an amino acid. Such mutations produce elongated proteins.

T/F: When the number of trinucleotide repeats in a gene is significantly above normal, it can produce a mutant phenotype.

True

New ____ mutations can often be detected by examining the inheritance of the trait in males.

X linked

In individuals who are most resistant to the toxic effects of parathion, the paraoxonase enzyme is/has ________ due to genetic variations.

able to rapidly metabolize the toxic metabolite of parathion

Huntington Disease results from extra copies of trinucleotide repeats in the Huntingtin gene. This is an example of a(n) ________ mutation.

allelic expansion

Women with breast cancers that are estrogen-sensitive ____.

are in danger of faster growth of cancer cells in the presence of estrogen

Mutations that occur in somatic cells ________.

are not passed onto the offspring

Since the urine of children with phenylketonuria contains phenylpyruvic acid, the defective enzyme in these individuals must normally ________ during the metabolism of phenylalanine.

convert phenylpyruvic acid to other end products

Lactase is an _______ that breaks down the lactose in milk into two simple sugar molecules.

enzyme

Genetic imprinting is caused by ____.

epigenetic changes to DNA

Several lines of research provide strong evidence that ____ to environmental signals influence behavior.

epigenetic responses

A two-nucleotide insertion mutation that results in conversion of an amino acid codon to a stop codon is known as a(n) ________.

frameshift

Insertion or deletion of a nucleotide in a gene causes a type of mutation called a(n) ________ mutation.

frameshift

The disease _______ is caused by a disruption in the body's ability to break down galactose, one of the two sugars found in lactose.

galactosemia

Women with genotypes that lead to decreased CYP2D6 activity ________.

need high doses of tamoxifen for treatment of breast cancer

In the United States, parathion is the most widely used member of a class of ____.

organophosphate insecticides

The science of developing drugs that are personalized to an individual's genotype is known as ________.

pharmacogenomics

The ability to taste PTC and other bitter chemicals is controlled by ____.

proteins on the surface of receptor cells

XP (xeroderma pigmentosum) is an autosomal recessive disorder caused by mutations in DNA ____ genes.

repair

The hemoglobin molecule ____.

transports oxygen from the lungs to the cells of the body

DNA methylation in promoter regions of genes ________.

turns off gene expression

HbA, the adult form of hemoglobin, consists of ________ and ________.

two alpha globins; two beta globins

Several genetic disorders, including Fanconi anemia and ataxia telangiectasia, are caused by mutations in ____.

DNA repair genes

Sense mutations produce ____.

elongated proteins

In some parts of the United States where PBDEs are not banned, samples of human milk contain ________ PBDEs than in European countries, where this chemical is banned.

10-100 times more

When ____ is incorporated into DNA or RNA during synthesis, it will create a(n) ____.

5-bromouracil; nucleotide substitution mutation

What occurs in a missense mutation?

A single amino acid is substituted for another in a protein.

______________ are mutations involving the increase of the number of repeat sequences in genes.

Allelic expansion

If a genetic disorder appears in a family with no prior history, and is fully expressed by everyone carrying that allele, it is most likely a(n) ____ trait.

Autosomal dominant

Radiation normally present in the environment that contributes to radiation exposure is called ________ radiation.

Background

________ build(s) new DNA molecules and proofreads the new strand to detect and correct any errors.

DNA polymerase

The study of genetic variations that affect people's responses to environmental agents, including man-made chemicals, is called _________.

Ecogenetics

_________ are proteins that catalyze biochemical reactions and are vital components of the cell's metabolic pathways.

Enzymes

The epigenetic state of a cell is called its __________.

Epigenome

What is the largest single source of radiation exposure for the average person in the U.S.?

Radon

Mutagenic chemicals that ____ and are incorporated into DNA or RNA during synthesis are called base analogs.

Resemble nucleotides

________ allow(s) for noncomplementary base pairing, which results in permanent mutations after DNA replication.

Tautomeric shifts

Why are the red blood cells sickle-shaped in individuals with sickle cell anemia?

The defective hemoglobin molecules form long fibers, which distort and harden the cell membrane.

Galactosemia is an inherited disorder caused by ____ galactose.

The inability to break down

________ genes tend to have high DNA mutation rates.

Trinucleotide repeat-containing

Results from the study of globin variants indicate that ____.

a change in a single nucleotide is sufficient to cause a genetic disorder

PBDEs are ____.

banned in many European countries but permitted in most states in the United States

A purine or pyrimidine that differs in chemical structure from those normally found in DNA or RNA is called a(n) ________.

base analog

Chemical mutagens that incorporate into DNA or RNA molecules are called ________.

base analogs

Gaucher's disease is caused by a mutation in the GBA gene, which results in the build-up of fat in the liver, spleen, and bone marrow; therefore, the GBA protein must normally function to ________.

break down fat

The flaking of skin after a sunburn is an example of ________.

cell suicide

As radiation strikes molecules in cells, it creates ____.

charged atoms called ions

As DNA polymerase synthesizes a new DNA strand, it can ____.

detect an incorrect nucleotide

The science that describes an individual's sensitivity to chemical toxins is known as ________.

ecogenetics

Selective expression of either the maternal or paternal copy of a gene is called _______.

genetic imprinting

The selective activation or silencing of either the maternal or paternal copy of a gene is called _______.

genetic imprinting

Because many imprinted genes control the timing and patterns of prenatal growth, abnormal imprinting can cause ________, which is seen in disorders such as Beckwith-Wiedemann syndrome.

growth disorders

The red blood cells of people with sickle cell anemia have abnormal shapes due to ____.

hemoglobin molecules with mutant beta globin subunits sticking together and forming long fibers in the cytoplasm

Methylation of promoter regions in DNA loosens the winding of the DNA around ________, making the promoters available for transcription and hence epigenetic changes.

histones

Measuring how DNA methylation patterns on the glucocorticoid receptor gene promoter change in response to environmental signals can reveal ________.

how epigenetics controls the stress response

Thalassemias are associated with a(n) ____.

imbalance in the production of alpha or beta globin

Lactose intolerance is caused by a(n) ____.

inability to digest lactose

Individuals who are lactose intolerant do not make ________; therefore, they cannot metabolize lactose.

lactase

Mutations that result in the production of a defective CFTR protein inserted into the cell membrane cause ________ disease phenotypes.

milder

Individuals who are able to taste PTC are ________.

more sensitive to strong tastes, such as capsaicin

Mutation rates of human genes are expressed as the number of ____.

mutated alleles per gene in each generation

nonsense mutation

mutation that substitute one of the stop codons prematurely into the sequencing of an amino acid

nucleotide substitution

mutations that alter the sequence but not the number of nucleotides

Cells that accumulate significant DNA damage may become dormant, a condition known as _______.

senescence

Dietary treatment of galactosemia ____.

should be started within a few days after birth

Mutations in _____________ cells will be passed on by cell division, but cannot be transmitted to future generations.

somatic

missense mutation

substitution of one amino acid for another in a protein caused by a single nucleotide change

The specific chemical compound that is acted on by a particular enzyme is called a(n) _____.

substrate

frameshift mutation

the insertion or deletion of extra bases other than in multiples of three in DNA leading to a shift in the codon reading frame

In sickle cell anemia, affected individuals carry ____.

the same single nucleotide substitution