In genetics and developmental biology, somatic-cell nuclear transfer is a laboratory technique for creating a clone embryo with a
donor somatic nucleus.
Artificial embryo splitting or embryo twinning, a
technique that creates monozygotic twins from a single embryo, is not considered in the same fashion as other methods of cloning. During that procedure, an donor embryo is split in two distinct embryos, that can then be transferred via embryo transfer.
Monomer of DNA
Nucleotide
Nucleotides are organic molecules that serve as the monomers, or subunits, of nucleic acids like DNA and RNA.
Copy of an organism
Clone
Chromosome that does not determine sex in humans
Autosome
An autosome is a chromosome that is not an allosome (i.e., not a sex chromosome).
Autosomes appear in pairs whose members have the same form but differ from other pairs in a diploid cell, whereas members of an allosome pair may differ from one another and thereby determine sex.
Replication enzyme
DNA polymerase
A DNA polymerase is a cellular or viral enzyme that synthesizes DNA molecules from their nucleotide building blocks, distinguished from RNA polymerase and other polymerases.
Can cause cancer
Mutation
One old, one new
Semiconservative replication describes the mechanism by which DNA is replicated in all known cells. This mechanism of replication was one of three models originally proposed for DNA replication:
Semiconservative replication would produce two copies that each contained one of the original strands and one new strand.
Conservative replication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.
Dispersive replication would produce two copies of the DNA, both containing distinct regions of DNA composed of either both original strands or both new strands.
What percentage of cloned implanted embryos will result in a live birth?
B. Less than 2%
Typically, less than 2 percent of the implanted embryos result in a live
birth. Of the clones that survive, many have serious health problems.
Which of the following is not a goal of cloning?
C. All these are goals of cloning.
A chromosome consists of
D. DNA and proteins
Stretched out end to end, the DNA in a single human cell would be about 2 meters (6.5 feet) long. How can that much DNA pack into a nucleus that is less than 10 micrometers in diameter? Such tight packing is possible because proteins associate with the DNA and help keep it organized.
Human body cells have
E. 46 chromosomes
Chromosomes in a karyotype are arranged by
E. All of these
In which of the following organisms would a karyotype not be valuable for revealing the sex of the individual?
E. Turtles
A karyotype is the number and appearance of chromosomes in the
nucleus of a eukaryotic cell. The term is also used for the complete set
of chromosomes in a species, or an individual organism.
Which of the following is not a nucleotide in DNA?
B. Quinine
Quinine is a natural white crystalline alkaloid having antipyretic (fever-reducing), antimalarial, analgesic (painkilling), and anti-inflammatory properties and a bitter taste.
Which of the following people discovered the helical structure of DNA?
E. Rosalind Franklin
Rosalind Franklin was a British biophysicist and X-ray crystallographer who made critical contributions to the understanding of
the fine molecular structures of DNA, RNA, viruses, coal, and graphite.
Erwin Chargaff discovered two rules on the
basis of which we were able to figure out that the DNA had a double helical structure. The first rule was that the DNA.
Francis Harry Compton Crick, OM, FRS was an English molecular biologist, biophysicist, and neuroscientist, most noted for being a
co-discoverer of the structure of the DNA molecule in 1953 with James
Watson.
Maurice Wilkins CBE FRS was an English physicist and molecular biologist, and Nobel Laureate whose research contributed to the scientific understanding of phosphorescence, isotope separation, optical microscopy and X-ray diffraction, and to the development of radar.
James Dewey Watson, is an American molecular biologist, geneticist and zoologist, best known as a co-discoverer of
the structure of DNA in 1953 with Francis Crick.
The DNA double helix was revealed to the world in
C. 1953
A strand of DNA is AACCTTGG. Its complementary strand would be
E. TTGGAACC
In eukaryotes, DNA replication occurs in the
D. Nucleus
DNA replication is described as
C. Semi-conservative
How fast can bacteria replicate DNA?
B. 1000 nucleotides per second
Which wavelength of light can induce a covalent dimer between neighboring thymine and cytosine in DNA?
D. 350 nm
The enzyme that produces a complementary strand of DNA is called
B. DNA polymerase
Which of the following is not true of reproductive cloning?
C. It occurs only in sporulation.
Somatic cell nuclear transfer can produce clones from an animal that is
C. All of these
Somatic cell nuclear transfer (SCNT) uses DNA from a(an)
C. Adult cell
Clones never
E. All these commonly afflict clones.
Which of the following have not been cloned?
B. Humans
DNA replication enzyme; uses a DNA template to assemble a complementary strand of DNA.
DNA polymerase
One of two attached members of a duplicated eukaryotic chromosome.
Sister chromatids
Technology that produces genetically identical individuals.
Reproductive cloning
Having two of each type of chromosome characteristic of the species (2n).
Diploid
Of a duplicated eukaryotic chromosome, constricted region where sister chromatids attach to each other.
Centromere
Member of a pair of chromosomes that differs between males and females.
Sex chromosomes
Any chromosome other than a sex chromosome.
Autosomes
Short, single strand of DNA or RNA that base-pairs with a targeted DNA sequence.
Primer
Type of protein that structurally organizes eukaryotic chromosomes.
Histones
The order of nucleotides in a strand of DNA.
DNA sequence
Process by which cells become specialized during development; occurs as different
cells in an embryo begin to use different subsets of their DNA.
Differentiation
Genetically identical copy of an organism.
Clones
A structure that consists of DNA and associated proteins; carries part or all of a cell's genetic information.
Chromosomes
Permanent change in DNA sequence.
Mutation
Energy-requiring process by which a cell duplicates its DNA before it divides.
DNA replication
The sum of all chromosomes in a cell of a given species.
Chromosome number
Describes the process of DNA replication, which produces two copies of a DNA molecule: one strand of each copy is new, and the other is a strand of the
original DNA.
Semiconservative replication
Reproductive cloning method in which the DNA from a body cell is transferred into an unfertilized egg.
Somatic cell nuclear transfer (SCNT)
Image of an individual's complement of chromosomes arranged by size, length, shape, and centromere location.
Karyotype
A chromosome contains many genes that are transcribed into different ___.
B. RNAs
RNAs form by ___; proteins form by ___.
C. transcription; translation
Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA by the enzyme RNA polymerase.
Translation is the process in which cellular ribosomes create proteins. It is part of the process of gene expression.
The main function of a DNA molecule is to ___.
B. store heritable information
The main function of an mRNA molecule is to ___.
store heritable information
carry DNA's genetic message for translation
form peptide bonds between amino
acids carry amino acids to ribosomes
carry DNA's genetic message for translation
Where does transcription take place in a eukaryotic cell?
C. nucleus
Translation takes place in the ___ of all cells.
C. cytoplasm
Up to how many amino acids can be encoded by a gene that consists of 45 nucleotides plus a stop codon?
15
Most codons specify a(n) ___.
B. amino acid
The genetic code is traditionally represented as a RNA codon table due to the biochemical nature of the protein translation
process. However, with the rise of computational biology and genomics,
proteins have become increasingly studied at a genomic level. As a result, the practice of representing the genetic code as a DNA codon table has become more popular.
A series of codons in part of a messenger RNA (mRNA) molecule. Each codon consists of three nucleotides, usually representing a single amino acid.
___ are mutations.
B. Base-pair, substitutions, Insertions and Deletions
A transposable element is a DNA sequence that can change its position within the genome, sometimes creating or reversing mutations and altering the cell's genome size.
Homeotic gene products ___.
a. map out the overall body plan in embryos
b. control the formation of specific body parts
b. control the formation of specific body parts
Homeotic genes cause the development of specific structures in plants and animals.
A gene that is knocked out is ___.
A. either deleted or expressed
Which of the following includes all of the others?
B. master genes
A cell with a Barr body is ___.
A. from a female mammal
A Barr body is the inactive X chromosome in a female somatic cell, rendered inactive in a process called lyonization, in those species in
which sex is determined by the presence of the Y or W chromosome rather than the diploidy of the X or Z.
True or false? Some gene expression patterns are heritable.
True.
May cause epigenetic effects
Methylation
Linear order of nucleotides
DNA sequence
Assembles amino acids
Ribosome
Translated to protein
mRNA
Set of 64 codons
Genetic code
Cells become specialized
Differentiation
Gets around
Transposable element
Put the following processes in order of their occurrence during expression of a eukaryotic gene:
An experiment in which a gene is deliberately inactivated in a living organism.
Knockout
Mutation in which one or more nucleotides become inserted into DNA.
Insertion
Nucleotide sequence that remains in an RNA after post-transcriptional modification.
Exons
Inactivated X chromosome in a cell of a female mammal. The other X chromosome is active.
Barr body
Enzyme that carries out transcription.
RNA polymerase
Nucleotide sequence that intervenes between exons and is excised during post-transcriptional modification.
Introns
In DNA, a sequence to which RNA polymerase binds.
Promoter
Protein that influences transcription by binding to DNA.
Transcription factors
DNA sequence that encodes an RNA or protein product.
Gene
Type of RNA that has a protein-building message.
Messenger RNA (mRNA)
Mutation in which one or more nucleotides are lost.
Deletion
Refers to DNA modifications such as methylation that do not involve a change in DNA sequence.
Epigenetic
Set of three nucleotides in a tRNA; base-pairs with mRNA codon.
Anticodon
Mutation in which a single base pair changes.
Base-pair substitution
Complete set of sixty-four mRNA codons.
Genetic code
Type of RNA that becomes part of ribosomes.
Ribosomal RNA (rRNA)
Type of RNA that delivers amino acids to a ribosome during translation.
Transfer RNA (tRNA)
Process by which enzymes assemble an RNA using the nucleotide sequence of a gene as a template.
Transcription
Process by which the information in a gene guides assembly of an RNA or protein product.
Gene expression
Process by which a polypeptide chain is assembled from amino acids in the order specified by an mRNA.
Translation
Gene encoding a product that affects the expression of many other genes.
Master genes
In mRNA, a nucleotide triplet that codes for an amino acid or stop signal during translation.
Codon
Ricin is not
A. Counteracted by any antidote
Ricin is a highly toxic, naturally occurring lectin produced in the seeds of the castor oil plant Ricinus communis. A dose the size of a few grains of table salt can kill an adult human.
Ricin is toxic to cells because it
E. Damages ribosomes
The RNA destined to be translated into amino acids, a protein, is
B. mRNA
mRNA - Messenger RNA is a large family of RNA molecules that convey genetic information from DNA to the ribosome, where they specify the amino acid sequence of the protein products of gene expression.
tRNA - A Transfer RNA is an adaptor molecule composed of RNA, typically 73 to 94 nucleotides in length, that serves as the physical link between the nucleotide sequence of nucleic acids and the amino acid sequence of proteins.
rRNA - ribosomal ribonucleic acid is the RNA component of the ribosome, and is essential for protein synthesis in all living organisms.
Which sequence is correct?
A. DNA → RNA → protein
Which of the following is found in RNA but not DNA?
C. Uracil
Uracil is one of the four nucleobases in the nucleic acid of RNA that are represented by the letters A, G, C and U. The others are adenine, cytosine, and guanine. In RNA, uracil binds to adenine via two hydrogen bonds.
Thymine is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nucleobase.
Cytosine is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine.
Guanine is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine. In DNA, guanine is paired with cytosine.
Adenine is a nucleobase (a purine derivative) with a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate (ATP) and the cofactors nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD), and protein synthesis, as a chemical component of DNA and RNA. The shape of adenine is complementary to either thymine in DNA or uracil in RNA.
RNA polymerase would produce what complement based on the DNA sequence AATTCCGG?
C. UUAAGGCC
Which of the following is present in the newly transcribed RNA but not in the finished RNA?
B. Introns
An intron is any nucleotide sequence within a gene that is removed by RNA splicing while the final mature RNA product of a gene is being generated.
Which of the following mRNA codon is for leucine?
A. All of these
Which of the following would stop translation?
B. UGA
In the genetic code, a stop codon (or termination codon) is a nucleotide triplet within messenger RNA that signals a termination of translation. Proteins are based on polypeptides, which are unique sequences of amino acids. Most codons in messenger RNA (from DNA) correspond to the addition of an amino acid to a growing polypeptide chain, which may ultimately become a protein. Stop codons signal the termination of this process by binding release factors, which cause the ribosomal subunits to disassociate, releasing the amino acid chain.
Translation ends when a stop codon is reached. In the standard genetic code, there are several stop codons:
in RNA:
UAG ("amber")
UAA ("ochre")
UGA ("opal")
in DNA:
TAG ("amber")
TAA ("ochre")
TGA ("opal" or "umber")
Mitochondria and chloroplasts use a slightly modified version of the genetic code that most closely resembles
D. Bacteria
The most accurate term used to describe the joining of two amino acids in a polypeptide chain is
A. Peptide bond
A peptide bond (amide bond) is a covalent chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, causing the release of a molecule of water (H2O), hence the process is a dehydration synthesis reaction (also known as a condensation reaction), and usually occurs between amino acids.
What is the first step in translation?
D. mRNA binds to the small ribosomal subunit.
How many codons are within the ribosomal complex at any one time?
D. 2
Which of the following mutations would have the least impact on a protein?
C. Base-pair substitution.
Which of the following is not true of human hemoglobin?
D. All these are true.
Which of the followings statements pertaining to sickle-cell anemia is not true?
D. It is the result of a frameshift.
Which of the following does not impact gene expression?
D. All these may impact gene expression.
Which of the following statements about epigenetics is not true?
C. Direct methylation of nucleotides may be a factor.
Epigenetics is the study of heritable changes in gene activity that are not caused by changes in the DNA sequence; it also can be used to describe the study of stable, long-term alterations in the transcriptional potential of a cell that are not necessarily heritable.
Which of the following is not a source of ribosome inactivating proteins (RIPs)?
B. Human immunodeficiency virus (HIV).
How rapidly can ricin inactivate ribosomes?
B. One ricin can inactivate 1000 ribosomes per minute.
In a eukaryotic cell cycle, the interval between mitotic divisions when a cell grows, roughly doubles the number of its cytoplasmic components, and replicates its DNA.
Interphase
A neoplasm that forms a lump.
Tumor
Process in which homologous chromosomes exchange corresponding segments during meiosis.
Crossing over
Nuclear division process that halves the chromosome number. Basis of sexual reproduction.
Meiosis
The process in which cancer cells spread from one part of the body to another.
Metastasis
Having one of each type of chromosome characteristic of the species.
Haploid
Stage of mitosis during which chromosomes condense and become attached to a newly forming spindle.
Prophase
In a dividing animal cell, the indentation where cytoplasmic division will occur.
Cleavage furrow
Stage of mitosis at which all chromosomes are aligned in the middle of the cell.
Metaphase
Reproductive mode by which offspring arise from a single parent only.
Asexual reproduction
Gene that helps transform a normal cell into a tumor cell.
Oncogene
Reproductive mode by which offspring arise from two parents and inherit genes from both.
Sexual reproduction
Stage of mitosis during which chromosomes arrive at opposite ends of the cell and decondense, and two new nuclei form.
Telophase
Disease that occurs when a malignant neoplasm physically and functionally disrupts body tissues.
Cancer
Male gamete.
Sperm
First cell of a new individual; forms by the fusion of two haploid gametes.
Zygote
Paired chromosomes with the same length, shape, and set of genes.
Homologous chromosomes
Forms of a gene with slightly different DNA sequences; may encode slightly different versions of the gene's product.
Alleles
Apparatus that moves chromosomes during nuclear division; consists of dynamically assembled and disassembled microtubules.
Spindle
An accumulation of abnormally dividing cells.
Neoplasm
Stage of mitosis during which sister chromatids separate and move toward opposite sides of the cell.
Anaphase
A series of events from the time a cell forms until its cytoplasm divides.
Cell cycle
Mature, haploid reproductive cell.
Gametes
Female gamete.
Eggs
Nuclear
division mechanism that maintains the chromosome number. Basis of body
growth, tissue repair and replacement in multicelled eukaryotes; also
asexual reproduction in some plants, animals, fungi, and protists.
Mitosis
Stages of the cell cycle which include the time that the cell is in the process of dividing
Mitosis
Stages of the cell cycle which include the time that the cell is not actively dividing
Interphase
The G1 stage of Interphase is ___.
A. when most of the cellular metabolic business occurs
The S stage of Interphase is ___.
B. the time in which the cell copies its DNA
The G2 stage of Interphase is ___.
A. the interval when the cell prepares to divide
The G2 stage of Interphase is ___.
A. the time after DNA replication and before the cell divides
The G1 stage of Interphase is ___.
A. when the cell only has one set of chromosomes
The S stage of Interphase is ___.
B. the time of DNA replication
The S stage of Interphase is ___.
C. when the cell copies its DNA in order to have two full sets of chromosomes
The G1 stage of Interphase is ___.
A. the interval of cell growth before DNA replication
The G2 stage of Interphase is ___.
B. when the cell has two complete sets of chromosomes and is preparing to divide
In humans there are ___ total individual chromosomes, but there are ___ pairs of homologous chromosomes.
46; 23
Homologous: having the same relation, relative position, or structure, in particular.
Chromosomes that are the same size and shape are the homologous pairs.
A fruit fly has 8 total chromosomes. Therefore, they have ___ homologous chromosomes pairs and, when a cell has duplicated its DNA and mitosis begins, has ___ sister chromatids.
4; 16
Mnumonic device to help remember the order of the stages of mitosis
"Puppies Pee on the MAT" (Prophase, Metaphase, Anaphase, Telophase)
Which of the following factors might cause checkpoint genes to interrupt cell division?
B. All of these can be factors
An abnormal mass of tissue arising from an abnormal proliferation of cells.
Neoplasm
A doctor who specializes in the study and treatment of cancer
Oncologist
Symbol for diploid cells
2n
Symbol for haploid cells
n
Crossing over is an event that occurs during ___.
A. prophase I of meosis
Mitosis and cytoplasmic division function in ___.
E. both asexual reproduction of single-celled eukaryotes and growth and tissue repair in multicelled species
A cell with two of each type of chromosome has a(n) chromosome number.
D. diploid
How many chromatids does a duplicated chromosome have?
B. two
Except for a pairing of sex chromosomes, homologous chromosomes ___.
B. all of these
Interphase is the part of the cell cycle when ___.
A. a cell grows and duplicates its DNA
After mitosis, the chromosome number of the two new cells is ___ the parent cell's.
D. the same as
Only is not a stage of mitosis.
C. interphase
The main evolutionary advantage of sexual over asexual reproduction is that it produces ___.
A. more variation among offspring
Alternative forms of the same gene are ___.
C. alleles
A gamete is a cell that fuses with another cell during fertilization (conception) in organisms that reproduce sexually.
Homologous is having the same relation, relative position, or structure, in particular.
Oncogenes are genes that, in certain circumstances, can transform a cell into a tumor cell.
Meiosis functions in ___.
D. sexual reproduction in plants and animals
Crossing over mixes up ___.
B. alleles
Sexual reproduction in animals requires ___.
B. meiosis and fertilization
Chart showing the pattern of inheritance of a trait in a family.
Pedigrees
A chromosome abnormality in which there are too many or too few copies of a particular chromosome.
Aneuploidy
Having three or more of each type of chromosome characteristic of the species.
Polyploid
An individual's observable traits.
Phenotype
Cross between two individuals identically heterozygous for one gene; for example Aa × Aa.
Monohybrid cross
The particular set of alleles that is carried by an individual's chromosomes.
Genotype
Refers to an allele with an effect that is masked by a dominant allele in heterozygous individuals.
Recessive
Refers to a gene whose product influences multiple traits.
Pleiotropic
Effect in which two alleles are both fully expressed in heterozygous individuals and neither is dominant over the other.
Codominance
Diagram used to predict the genetic and phenotypic outcome of a cross.
Punnett square
Bell-shaped
curve; typically results from graphing frequency versus distribution for a trait that varies continuously in a population.
Bell curve
Having identical alleles of a gene.
Homozygous
Polygenic inheritance, in which a trait is influenced by the products of multiple genes.
Epistasis
Cross between two individuals identically heterozygous for two genes; for example AaBb × AaBb.
Dihybrid cross
Refers to an allele that masks the effect of a recessive allele in heterozygous individuals.
Dominant
Effect in which one allele is not fully dominant over another, so the heterozygous phenotype is between the two homozygous phenotypes.
Incomplete dominance
Having two different alleles of a gene.
Heterozygous
Failure of chromosomes to separate properly during nuclear division.
Nondisjunction
A range of small differences in a shared trait.
Continuous variation
CFTR is a gene that encodes a protein responsible for transporting ________ out of cells.
C. Chloride
Cystic fibrosis is caused by
E. A gene mutation
If an organism has two alleles at a specific gene, and only the one for tall height is expressed, which of the following statements is false?
C. The tall allele is recessive.
Using modern terms, Mendel was not responsible for discovering
E. DNA
Two heterozygous parents are crossed. What percentage of their offspring will express the recessive trait? (Hint: Use a Punnett square.)
B. 25%
In a dihybrid cross, an individual that is homozygous dominant for both alleles is crossed with an individual that is homozygous recessive for both alleles. What percentage of their offspring will express the recessive traits? (Hint: Use a Punnett square.)
C. 0%
A red parent and white parent are crossed, and the offspring are pink. This is an example of
B. Incomplete dominance
Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely dominant over the other allele.
Epistasis is when the effect of one gene depends on the presence of one or more 'modifier genes' (genetic background).
Pleiotropy occurs when one gene influences multiple, seemingly unrelated phenotypic traits, an example being phenylketonuria, which is a human disease that affects multiple systems but is caused by one gene defect.
Human blood types reveal
D. Dominance and codominance
Epistasis is when the effect of one gene depends on the presence of one or more 'modifier genes' (genetic background).
Which of the following is not true of changes in DNA methylation?
E. They represent a change in nucleotide sequence.
DNA methylation is a biochemical process whereby a methyl group is added to the cytosine or adenine DNA nucleotides.
A methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms — CH3.
A phenotype is the composite of an organism's observable characteristics or traits, such as its morphology, development, biochemical or physiological properties, phenology, behavior, and products of behavior.
Which of the following is most likely to result in continuous variation in phenotypic expression?
D. Multiple genes, each with multiple alleles for a given trait
In a pedigree, a solid circle would indicate a
D. Female who is affected
Which of the following is a single-gene disorder?
D. None of these
A particular disorder is found to express more commonly in males than females. This suggests the disease is
B. X-linked recessive
X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males and in females who are homozygous for the gene mutation.
Autosomal recessive: A genetic condition that appears only in individuals who have received two copies of an autosomal gene, one copy from each parent.
Autosomal dominant: a gene on one of the non-sex chromosomes that is always expressed, even if only one copy is present.
In which of the following could a "carrier" not exist?
C. Autosomal dominant
A human is born not having two of a particular chromosome in a set. Which of these terms could not potentially describe this condition?
A. Polyploidy
Monosomy: the condition of having a diploid chromosome complement in which one (usually the X) chromosome lacks its homologous partner.
Trisomy: a condition in which an extra copy of a chromosome is present in the cell nuclei, causing developmental abnormalities.
Nondisjunction: the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei.
Polyploidy: the heritable condition of possessing more than two complete sets of chromosomes.
Aneuploidy: a condition in which the chromosome number is not an exact multiple of the number characteristic of a particular species. An extra or missing chromosome is a common cause of genetic disorders including human birth defects.
Which of the following is an autosomal aneuploidy?
D. Down syndrome
An autosome is a chromosome that is not an allosome (i.e., not a sex chromosome).
Turner syndrome is a genetic condition in which a female does not have the usual pair of two X chromosomes.
Trisomy 21 (formerly known as Down syndrome) is caused by an extra chromosome 21.
Klinefelter syndrome (KS) (also known as XXY syndrome) is caused by the presence of two X and one Y chromosomes (47,XXY).
Triple X syndrome, also called trisomy X or 47,XXX, is characterized by the presence of an additional X chromosome in each of a female's cells.
Which of the following can only be done with in vitro fertilization?
D. Preimplantation diagnosis
Which of the following is both most invasive and most dangerous?
E. Fetoscopy
CVS is a test made in early pregnancy to detect congenital abnormalities in the fetus. A tiny tissue sample is taken from the villi of the chorion, which forms the fetal part of the placenta.
Preconception and prenatal genetic screening: Blood tests offered to pregnant women to screen whether they are at increased risk of carrying a baby with certain conditions, such as Down Syndrome or an open neural tube defect. This screening is optional.
Fetoscopyis an endoscopic procedure during pregnancy to allow access to the fetus, the amniotic cavity, the umbilical cord, and the fetal side of the placenta. A small (3–4 mm) incision is made in the abdomen, and an endoscope is inserted through the abdominal wall and uterus into the amniotic cavity.
Amniocentesis is the sampling of amniotic fluid using a hollow needle inserted into the uterus, to screen for developmental abnormalities in a fetus.
Individuals who are heterozygous for the cystic fibrosis (CF) gene defect are more resistant to
B. Typhoid fever
How old is the cystic fibrosis allele?
E. Over 50,000 years
___ is a complex gene interaction, wherein multiple genes affect a single phenotypic trait.
C. Epistasis
Pleiotropy is the production by a single gene of two or more apparently unrelated effects.
Epistasis is the interaction of genes that are not alleles, in particular the suppression of the effect of one such gene by another.
Codominanceis a relationship between two versions of a gene. Individuals receive one version of a gene, called an allele, from each parent. If the alleles are different, the dominant allele usually will be expressed, while the effect of the other allele, called recessive, is masked.
Assuming all alleles have
a clear dominant/recessive relationship, a dihybrid cross leads to a
phenotypic ratio in offspring that is typically close to ___.
B. 9:3:3:1
The probability of a crossover occurring between two genes on the same chromosome ___.
B. increases with the distance between them
___ alleles are both fully and equally expressed.
B. Codominant
A bell curve indicates ___ in a trait.
B. continuous variation
Constructing a pedigree is particularly useful when studying inheritance patterns in organisms that ___.
C. produce few offspring per generation
A female child inherits one X chromosome from her mother and one from her father. What sex chromosome does a male child inherit from each of his parents?
X from mom, Y from dad
Nondisjunction at meiosis can result in ___.
C. aneuploidy
Nondisjunction is the failure of chromosome pairs or sister chromatids to separate properly during cell division.
Aneuploidy is a condition in which the chromosome number is not an exact multiple of the number characteristic of a particular species.
True or false? All traits are inherited in a predictable way.
False
If one parent is heterozygous for a dominant autosomal allele and the other parent does
not carry the allele, a child of theirs has a chance of being heterozygous.
C. 50 percent
Klinefelter syndrome (XXY) is most easily diagnosed by ___.
c. phenotypic treatment
A. karyotyping
Karyotyping is a test to examine chromosomes in a sample of cells, which can help identify genetic problems as the cause of a disorder or disease.
Aneuploidy is a condition in which the chromosome number is not an exact multiple of the number characteristic of a particular species.
Phenotype is how the condition is expressed. Basically the symptoms of the gene mutation. Therefore, phenotypic treatments would be preventing a disorder from being expressed.
AaBb × AaBb
B. Dhybrid cross
In contrast to a monohybrid cross, a dihybrid cross is a cross between F1 offspring (first-generation offspring) of two individuals that differ in two traits of particular interest.
For example, BB × bb. B = brown. b = blue. BB = Dark brown. Bb = Brown (not blue). bb = Blue.
Aa × Aa
C. Monohybrid cross
A monohybrid cross is a genetic cross between homozygous individuals but with different alleles for a single gene locus of interest.
In genetics, a locus is the specific location of a gene or DNA sequence or position on a chromosome.
bb
B. Homozygous condition
Aa
B. Heterozygous condition
Extra sets of chromosomes
B. Polyploid
Syndrome
D. Symptoms of a genetic disorder
Aneuploidy
F. One extra chromosome
Nondisjunction during meiosis
E. Gametes end up with the wrong chromosome number
Epistasis
F. Two genes affect the same trait
Genotype
D. An individual's alleles
Human eye color
G. Varies continuously
Polyploid
G. Extra sets of chromosomes
Symptoms of a genetic disorder
C. Syndrome
One extra chromosome
E. Aneuploidy
Gametes end up with the wrong chromosome number
C. Nondisjunction during meiosis
Two genes affect the same trait
B. Epistasis
An individual's alleles
G. Genotype
Varies continuously
E. Human eye color
Author
Dienekes
ID
270720
Card Set
Genetics
Description
DNA is a very stable, passive molecule made of long strands of nucleotides, and the order of those nucleotides contains genetic information. The DNA sequence serves as a template for transcribing RNA with a complementary sequence and the RNA copy can then be translated by ribosomes that produce amino acid chains dictated by the RNA sequence. What proteins a cell produces, and thus what functions a cell engages in, depends largely on which of the many genes in the cell’s DNA are transcribed and translated.
