Homework #6

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

allelic expansion

Supertasters for the chemical PTC are ____ for the trait. a. heterozygous b. homozygous dominant c. either homozygous dominant or homozygous recessive d. either homozygous dominant or heterozygous e. homozygous recessive

b. homozygous dominant

Mutations are changes in the nucleotide sequence of DNA that ____. a. are always spontaneous b. are always chemically induced c. do not occur in the germ cells d. can be passed on to daughter cells e. do not occur in the somatic cells

d. can be passed on to daughter cells

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

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

false

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

frameshift

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

proofreading

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

true

Thalassemias are associated with a(n) ____. a. extended chain in beta globin b. imbalance in the production of alpha or beta globin c. amino acid substitution d. altered rate of oxygen transport e. excessive synthesis of beta globin

b. imbalance in the production of alpha or beta globin

When ____ is incorporated into DNA or RNA during synthesis, it will create a(n) ____. a. 5-bromouracil; nucleotide substitution mutation b. 5-bromouracil; frameshift mutation c. oxygen; nucleotide substitution mutation d. oxygen; base analog e. carbon; base analog

a. 5-bromouracil; nucleotide substitution mutation

What occurs in a missense mutation? a. A single amino acid is substituted for another in a protein. b. All of the amino acids beyond the mutation point are changed. c. A nucleotide is added to the DNA. d. A nucleotide is deleted from the DNA. e. The protein is always completely nonfunctional.

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

PBDEs are ____. a. banned in many European countries but permitted in most states in the United States b. banned worldwide but are still being used illegally c. banned in many Europeans countries and all states in the United States d. permitted in many European countries but banned in the United States e. permitted in only one European country and in only 11 states in the United States

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

As radiation strikes molecules in cells, it creates ____. a. charged atoms called ions b. excess copies of mRNA c. excess storage of tRNA d. excess DNA polymerase e. charged atoms called isotopes

a. charged atoms called ions

As DNA polymerase synthesizes a new DNA strand, it can ____. a. detect an incorrect nucleotide b. induce apoptosis when it detects a mistake in DNA synthesis c. not detect an incorrect nucleotide d. immediately stop the cell cycle e. induce senescence when it detects a mistake in DNA synthesis

a. detect an incorrect nucleotide

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

background

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

base analog

Several genetic disorders, including Fanconi anemia and ataxia telangiectasia, are caused by mutations in ____. a. DNA polymerase genes b. mitochondrial DNA c. DNA repair genes d. the cell wall e. ribosome structure

c. DNA repair genes

Results from the study of globin variants indicate that ____. a. extended chains of phosphorus molecules function to carry oxygen b. all of the changes in globin are due to changes in amino acid sequences c. a change in a single nucleotide is sufficient to cause a genetic disorder d. all amino acid substitutions cause severe phenotypic effects e. sickle cell anemia is not primarily an inherited disease

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

Women with breast cancers that are estrogen-sensitive ____. a. will often experience cancer remission with increased uptake of estrogen b. can exacerbate their symptoms with only a small increase in estrogen levels c. are in danger of faster growth of cancer cells in the presence of estrogen d. become ill when taking prescription estrogen e. do not produce their own estrogen and must obtain it through diet or supplements

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

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. a. Y-linked b. X-linked recessive c. autosomal dominant d. autosomal recessive e. mitochondrial

c. autosomal dominant

Genetic imprinting is caused by ____. a. a frameshift mutation b. deletion of an amino acid from the mRNA strand c. epigenetic changes to DNA d. insertion of a nucleotide into an exon e. a change in a termination codon

c. epigenetic changes to DNA

The red blood cells of people with sickle cell anemia have abnormal shapes due to ____. a. the attachment of phosphate groups to the hemoglobin molecules b. destruction of the hemoglobin molecules c. hemoglobin molecules with mutant beta globin subunits sticking together and forming long fibers in the cytoplasm d. the binding of methyl groups to the heme group of the hemoglobin molecule causing desiccation of the cells e. loss of hemoglobin through leaky cell membranes

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

Lactose intolerance is caused by a(n) ____. a. nucleotide substitution that prevents lactose production b. excess in lactose production c. inability to digest lactose d. accumulation of galactose-1-phosphate e. variant manifestation of galactosemia

c. inability to digest lactose

The ability to taste PTC and other bitter chemicals is controlled by ____. a. hormone levels that change throughout life b. the amount of PTC exposure as a child c. proteins on the surface of receptor cells d. the amount of capsaicin present in taste buds e. the presence of fats and sugars in the food being eaten

c. proteins on the surface of receptor cells

Galactosemia is an inherited disorder caused by ____ galactose. a. metabolizing excess fat molecules and attaching them to b. the excess break down of the protein c. the inability to break down d. the over-consumption of e. the overproduction of

c. the inability to break down

The hemoglobin molecule ____. a. is controlled by a single gene b. acts as a cell surface receptor c. transports oxygen from the lungs to the cells of the body d. prevents sickle cell anemia when present in high enough concentrations in the blood e. is involved in amino acid metabolism

c. transports oxygen from the lungs to the cells of the body

Several lines of research provide strong evidence that ____ to environmental signals influence behavior. a. base analog reactions b. base analog responses c. epigenetic feedback d. epigenetic responses e. base analog reconstruction due

d. epigenetic responses

In the United States, parathion is the most widely used member of a class of ____. a. chlorophosphate fungicides b. organophosphate herbicides c. chlorophosphate insecticides d. organophosphate insecticides e. chlorophosphate herbicides

d. organophosphate insecticides

What is the largest single source of radiation exposure for the average person in the U.S.? a. consumer products b. nuclear medicine c. medical X-rays d. radon e. cosmic

d. radon

In sickle cell anemia, affected individuals carry ____. a. one mutant allele in several genes b. a number of mutant alleles c. one of several different nucleotide substitutions d. the same single nucleotide substitution e. more than one nucleotide substitution

d. the same single nucleotide substitution

New ____ mutations can often be detected by examining the inheritance of the trait in males. a. mitochondrial b. imprinting c. autosomal dominant d. autosomal recessive e. X-linked

e. X-linked

Sense mutations produce ____. a. extra termination codons b. frameshifts c. cell death d. shortened proteins e. elongated proteins

e. elongated proteins

Mutation rates of human genes are expressed as the number of ____. a. nucleotides substitutions per gene b. frameshift mutations per genome c. mutated alleles per genome d. induced mutations per generation e. mutated alleles per gene in each generation

e. mutated alleles per gene in each generation

Mutagenic chemicals that ____ and are incorporated into DNA or RNA during synthesis are called base analogs. a. resemble amino acids b. resemble genes c. cause frameshift mutations d. cause deletion mutations e. resemble nucleotides

e. resemble nucleotides

Dietary treatment of galactosemia ____. a. need not begin until one or two months after birth b. consists of very low protein intake c. can usually be discontinued by the age of twelve d. completely eliminates symptoms of the disease e. should be started within a few days after birth

e. should be started within a few days after birth

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

genetic imprinting

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

somatic

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

substrate