Intro to Genetics Final Part 1
Repeating the sequence of the polymerase chain reaction doubles the number of DNA fragments each time.
True
Stem cells have the ability to differentiate to form specific cell types, which divide only slowly or not at all.
True
The basic method of DNA sequencing is the Sanger method.
True
About one in three people will be diagnosed with cancer at some time in his/her life.
True
Identical twins have identical ____, but they do not always have identical ____.
genotypes; phenotypes
Stem cells ____.
have the property of self-renewal by division
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
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
Women with PKU who eat a normal diet during pregnancy will have children with ____.
intellectual disability regardless of the child's genotype
The ability to smell ____.
is mediated by a family of about 400 genes
Epigenetics is the study of heritable alterations in gene expression caused by ____.
mechanisms that do not alter any DNA sequence
The ability to taste PTC and other bitter chemicals is controlled by ____.
proteins on the surface of receptor cells
A proto-oncogene ____.
regulates cell division
Probes can come from a variety of sources, such as ____________________.
related genes from other species
Many specialized cells, such as white blood cells, ____.
remain in G0 until stimulated by external signals to reenter the cell cycle and divide
Plasmids are short sequences of DNA used as primers in PCR.
False
The human genome contains approximately 40,000 genes.
False
Dr. Asbjorn Folling discovered that the blood of children affected by PKU reacted with ferric chloride to produce a green color indicating the presence of phenylalanine.
False
Enzymatic reactions convert products into substrates.
False
Even if detected early, PKU cannot be treated to prevent the development of intellectual disability.
False
Halogen-containing organic compounds persist in the environment for approximately five years.
False
Hereditary nonpolyposis colon cancer (HNPCC) requires only one mutational step to initiate the formation of a cancer cell.
False
In genetic goitrous cretinism, the phenotype is caused by accumulation of thyroid hormone and its breakdown products.
False
Mutations in germ cells are passed on only to other germ cells in members of future generations.
False
Nonsense mutations change termination codons into amino acid codons.
False
Parathion is effective and highly toxic to only about 5% of the human population.
False
People with cystic fibrosis display a single phenotype for the disorder.
False
Radiation and chemotherapy are the best treatments for cancer because they are very specific and destroy only cancerous cells.
False
The ras proto-oncogene family is a group of related genes that slow or stop the progression of cancer.
False
There are no direct-to-consumer genetic tests available that screen for breast cancer susceptibility.
False
In rapidly dividing cells, expression of BRCA1 and BRCA2 genes is the highest during the ____.
G1/S transition and into S phase
During gel electrophoresis, DNA fragments are separated by size.
True
A mutation of an autosomal recessive trait can remain undetected for generations.
True
Beckwith-Wiedemann syndrome is a cell growth disorder that causes enlarged organs, high birth weight, and predisposition to cancer.
True
Control systems in the cell can induce cell suicide, or apoptosis, in cells with excessive DNA damage.
True
In most human populations, lactase levels are highest soon after birth and drop off in middle-to-late childhood.
True
In people with PKU, phenylalanine from dietary proteins cannot be converted to tyrosine.
True
Linus Pauling and his colleagues discovered that a mutant gene involved in the synthesis of hemoglobin causes sickle cell anemia.
True
Most of the somatic cells in the body are structurally and functionally specialized and do not divide.
True
Most often, radiation doses are expressed in terms of damage.
True
PBDEs have not been linked directly to cancer in test animals.
True
People who can taste PTC are more likely than non-tasters to dislike broccoli and Brussels sprouts.
True
Proteins are essential parts of all structures and biological processes in cells.
True
The mutant BRCA1 gene imparts a dominantly inherited predisposition to breast cancer.
True
To interpret microarray data, it is necessary to understand the significance of the color of each dot within the array.
True
Viral infection is a major cause of cancer.
True
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
Nuclear transfer is a preferred method of cloning over embryo splitting because it ____.
results in a larger number of cloned offspring
Results from the study of globin variants indicate that ____.
a change in a single nucleotide is sufficient to cause a genetic disorder
Most often, genomic library screening uses ____.
a labeled, complementary single-stranded RNA or DNA molecule called a probe
A DNA microarray is ____.
a series of short nucleotide sequences placed on a solid support and has several uses
The translocation seen in the Philadelphia chromosome in myelogenous leukemia represents ____.
a specific chromosomal aberration accompanying a specific cancer
In most cases, cancer-causing mutations ____.
accumulate over a number of years
To clone an animal by embryo splitting, ____.
an unfertilized egg is collected from a donor mother and then fertilized in a dish by in vitro fertilization
The DNA sequencing reaction uses the enzyme DNA polymerase, a primer, and ____________________.
the four deoxynucleotides found in DNA
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
Southern blot is a method for ____.
transferring DNA fragments from a gel to a membrane filter and used in hybridization experiments
The hemoglobin molecule ____.
transports oxygen from the lungs to the cells of the body
During the process of gel electrophoresis, the DNA fragments migrate due to the effects of ____.
electrical charge
Sense mutations produce ____.
elongated proteins
Several lines of research provide strong evidence that ____ to environmental signals influence behavior.
epigenetic responses
Phenylalanine is a(n) ____ and the starting point for a network of metabolic pathways.
essential amino acid
Frameshift mutations change the number of ____ in the gene and usually cause large-scale changes in the ____ sequence of the protein.
nucleotides; amino acid
In the United States, parathion is the most widely used member of a class of ____.
organophosphate insecticides
Genetic goitrous cretinism and alkaptonuria are metabolic disorders in the ____ pathway.
phenylalanine
In the 1930s, Dr. Asbjor Folling described the metabolic disorder he called ____.
phenylketonuria
In addition to several other factors, the overall risks of environmental chemicals depend on genetically determined variations in the ____ involved in transport, metabolism, and excretion of these chemicals.
proteins
What is the largest single source of radiation exposure for the average person in the U.S.?
radon
During metabolism, cancer-causing ____ are generated.
reactive oxygen species (ROS)
Mutagenic chemicals that ____ and are incorporated into DNA or RNA during synthesis are called base analogs.
resemble nucleotides
The discovery that some bacteria ____ using enzymes that cut the viral DNA into pieces was one of the first steps in the development of recombinant DNA technology.
resist viral infection
When ____ is incorporated into DNA or RNA during synthesis, it will create a(n) ____.
5-bromouracil; nucleotide substitution mutation
Hereditary nonpolyposis colon cancers (HNPCC) ____.
are caused by several mutations in several different genes
Women with breast cancers that are estrogen-sensitive ____.
are in danger of faster growth of cancer cells in the presence of estrogen
PBDEs are ____.
banned in many European countries but permitted in most states in the United States
The field of epigenetics has opened the way for the development of a new class of anticancer drugs ____.
because of the discovery that epigenetic modification of key genes is important in some cancers and the fact that epigenetic changes are reversible
Mutations are changes in the nucleotide sequence of DNA that ____.
can be passed on to daughter cells
With the sequence of the gene-coding regions of the human genome in hand and the development of newer sequencing methods, scientists ____.
can now sequence and analyze the protein-coding genes in cancer cells
All epithelial cells in the inner lining of the large intestine that are heterozygous for an APC mutation ____.
can partially escape control of the cell cycle and lead to the formation of clusters of polyps
As radiation strikes molecules in cells, it creates ____
charged atoms called ions
Enzymes in the body catalyze biochemical reactions and ____.
convert substrate molecules into products
During in vitro fertilization, the fertilized egg ____.
develops in a Petri dish to form an embryo containing four to eight cells
During DNA sequencing, a laser beam scans the fragments on the electrophoresis gel to identify the ____________________.
end nucleotide by the color it fluoresces
Genetic imprinting is caused by ____.
epigenetic changes to DNA
In a typical application, a DNA microarray is used to compare the ____________________.
expression of genes in two different tissues
An advantage of YACs over other vectors in cloning human genes is that they ____.
have a higher capacity for carrying long DNA fragments
Common alleles of genes other than BRCA1 ____.
have a strong influence on whether a carrier will develop breast cancer
Adult cells cannot be used as the source of nuclei for cloning animals.
False
In June 2001 an announcement was made that a draft sequence of the ____________________ nucleotides in the human genome had been finished.
3.2 billion
About ____ of all cancer cases have a hereditary component.
5-10%
What occurs in a missense mutation?
A single amino acid is substituted for another in a protein
In recombinant DNA techniques, the gaps in the paired DNA fragments are closed by ____.
DNA ligase
Several genetic disorders, including Fanconi anemia and ataxia telangiectasia, are caused by mutations in ____.
DNA repair genes
Vectors can transfer ____.
DNA sequences into bacterial host cells for cloning
Cancer causing mutations are always the result of chromosomal rearrangements.
False
Edwin Southern and his colleagues started the field of genomics.
False
Growth hormones given to dairy cows would still be necessary to stimulate milk production in a cloned animal.
False
In the early years of the twentieth century, ____ proposed that some genetic disorders and abnormalities of metabolism are related.
Sir Archibald Garrod
A collection of clones containing all the DNA sequences carried by an individual is called a genomic library.
True
A restriction enzyme is a ____.
bacterial enzyme that cuts DNA at specific sites
A promoter is a regulatory region located at the ____.
beginning of a gene
The RB1 tumor-suppressor gene ____.
controls the G1/S checkpoint
Cancer-causing mutations of the cell cycle ____.
cause the cell to bypass checkpoints in the cycle
A yeast artificial chromosome (YAC) is a ____ that can accommodate large DNA inserts and uses the eukaryote yeast as a host cell.
cloning vector that has telomeres and a centromere
As DNA polymerase synthesizes a new DNA strand, it can ____.
detect an incorrect nucleotide
Supertasters for the chemical PTC are ____ for the trait.
homozygous dominant
During the denaturation step of PCR, ____ bonds are broken when DNA is heated.
hydrogen
The presence of phenylpyruvic acid in urine is directly linked to ____.
intellectual disability
If a cell begins to divide in an uncontrolled way, it ____.
may form a benign tumor
During the M checkpoint, the cell ____.
monitors attachment of spindle fibers to chromosomes
Mutation rates of human genes are expressed as the number of ____.
mutated alleles per gene in each generation
Because there was no previous history of hemophilia in Queen Victoria's family, and because she transmitted the mutant allele to a number of her children, it is reasonable to assume that ____.
she was a heterozygous carrier
Dietary treatment of galactosemia ____.
should be started within a few days after birth
PCR uses two components: ____________________ that serve as templates and primers that bind to regions on either side of the template to be copied.
single strands of DNA
According to the American Cancer Society, 30% of all cancer deaths in the U.S. are due to ____.
smoking
A characteristic of all cancers is that ____.
the cells divide continuously
Galactosemia is an inherited disorder caused by ____ galactose.
the inability to break down
In sickle cell anemia, affected individuals carry ____.
the same single nucleotide substitution