Genetics pp
Marfan syndrome, a dominant single-gene defect, is characterized by lens dislocation, long limbs, spndly fingers, a caved-in chest and a weakened aorta. This is an example of a(n):______ trait.
Pleiotropic
What is it: The same genetic variations or genotype combinations simultaneously affect more than one phenotype trait?
Pleiotropy
The substitution of one nucleotide for another is known as a(n)________
Point
Which of the following syndromes are associated with maternal disomy for chromosome 15?
Prader willi syndrome
Naturally occurring methods of recombining DNA within a species include:
crossing over and sexual reproduction
Huntington's disease is an example of a genetic disorder caused by
A late acting dominant allele
n the polymerase chain reaction (PCR) technique, a heating phase and a cooling phase alternate. An original sample of DNA would have to pass through how many total rounds of heating and cooling before a sample is increased eight times in quantity?
4
Which of the following is the description of an individual with cri-du-chat syndrome?
46, XY, 5p
How many tetrads are found in meiotic prophase in an organism with a diploid number of 12?
6
recombinant methods, the term "vector" refers to _______
A plasmid or other agent used to transfer DNA into a living cell
Which statement is true for the Rh blood group?
A blood sample either belongs to the ABO or to the Rh type incompatibility can cause problems during the second pregnancy with a heterozygous fetus
Taq polymerase:
A heat stable enzyme, used in PCR
man with type A blood marries a woman with type B blood. If both parent are homozygous, their offspring will have type _____ blood, which is an example of ___
AB; codominance
Housekeeping gene controls should be included in the following assays: a. Southern blot b. PCR c. R(everse)T(ranscriptase)-PCR d. DNA fingerprinting e. All of the above
All
The human genome is:
All of our DNA
farmer wishes to know whether his corn is homozygous or heterozygous for a particular trait. If it were homozygous a test cross would yield: (A eller B?)
All offspring with the parental phenotype (riktig?)
Homologous chromosomes are NOT necessarily identical in their _______
Alleles
Duchenne muscular dystrophy and Becker muscular dystrophy have different phenotypes, but they result from mutations in the same gene. This is an example of:
Allelic heterogeneity
What is it: different allelic combinations lead to similar phenotypes?
Allelic heterogeneity
Which stage of meiosis is the physical basis for Mendel's law of independent assortment?
Anaphase I
27. Which of the following syndromes are associated with paternal disomy for chromosome 15?
Angelman Syndrome
How are Klinefelter and Turner syndromes related
Answer is all : The result of non-disjunction b. Can be detected by karyotyping c. Involve abnormal number of X or Y chromosomes d. Have 44 autosomes e. all
Which statement if FALSE for inheritance?
Each chromosome out of the 23 inherited in an unchanged form either from the grandmother or from the grandfather
Myotonic dystrophy may show increasing severity and earlier age of onset in successive generations. This phenomenon is known as:
Anticipation
Several members of a family are affected by Fragile X syndrome, a genetic disease involving varying degrees of mental retardation. A female (Female A) in the family is only slightly affected, having math difficulties. Her daughter (Female B) is slightly more affected, with a squared jaw, large head and required some minor assisted education in high school. Female B has a son (Male C) who is severely affected with fragile X syndrome, i.e. he has the characteristic face (large head, large ears), macro-orchidism and severe mental retardation. This family represent an example of which genetic phenomenon?
Anticipation
Both sickle cell anemia and hemophilia
Are monogenic
DNA replication is said to be semiconservative. This mean that
Each new double helix consist of 1 old and 1 new strand
Huntington disease is a deadly dominant disease. How can this allele be transmitted from one generation to another if one copy is enough to make the carrier die?
Because symptoms appear between 30 and 50 years old and death occurs several years later
genetic defect in humans results in the absence of sweat glands in the skin. Some men have this defect all over their bodies, but in women it is usually expressed in a peculiar way. A woman with this defect typically has small patches of skin with sweat glands and other patches where sweat glands are lacking. This pattern suggests the phenotypic effect of: similarexample to tortoiseshell
Chromosome inactivation
Alleles that are both expressed in a heterozygote are
Codominant
A cystic fibrosis mutation screen of an affected child reveals that he carries the Delta F508 mutation on one chromosome and the G551D mutation on the other chromosome. Which of the following terms best describes his situation?
Complex heterozygosity
PCR is used to:
Copy DNA sequences
DNA fingerprinting is possible because
Each person has a unique set of genes
Polydactyly (extra finger) is a dominant trait in humans. A person who has polydactyly has parents who do not have polydactyly, and a maternal grandfather who does have polydactyly. What is the most likely explanation for this?
Incomplete penetrance
Which is true in connection with the ovogenesis? (oogenesis)
DNA replication happens before meiosis I
disease caused by an autosomal non-disjunction is
Down syndrome
Find the genetic disorder and protein mismatch X Chromosome
Duchenne muscular dystrophy - myosin
What is it: severity of the illness can often vary in the affected persons even suffering from the very same variant?
Expressivity
The effect of Barr body formation in mammals is that_______
Females are mosaics for heterozygous X-linked genes
In meiosis, what is meant by a tetrad of homologous chromosomes?
Four chromatids in the unit
Which one of these is caused by repeats of base triplets rather than a whole chromosome?
Fragile-X syndrome
Which of the following mutations would cause a frameshift and this likely be the most detrimental?
Insertion of 1 base pair
An interstitial deletion of paternal chromosome subregion 15q11-q13 results Prader- Willi syndrome (PWS). The deletion of the same subregion of maternal chromosome results another disease Angelman syndrome. The reason for this is:
Genomic imprinting
Find the genetic disorder and protein mismatch:
Hemophilia - hemoglobin
Mary's father has haemophilia, but her husband doesn't. What is the chance her son XR will have the disease? Write up the genotypes and the Punett square to prove the answer.
Hemophilia is sex linked recessive solve it she is hetero and father is sick 50 %
In meiosis I anaphase
Homologous chromosomes move toward opposite poles
Which of the following defines the pseudoautosomal region?
Homologous regions of the X and Y chromosomes
In which phase or stage do sister chromatids separate during meiosis?
In anaphase II
Which of the following is NOT true about mtDNA?
It has many DNA repair mechanisms
What is true about sister chromatid exchange?
It has no genetic consequence in most of the cases
What is the mode of inheritance of color blindness?
It is an autosomal dominant trait
Amniocentesis and chorionic villus sampling are both techniques used to________
Karyotype a fetus b. Determine sex of a fetus c. Look for chromosomal aberrations d. Perform biochemical studies e. All of the above answers are correct All are correcttttttt
Klinefelter's syndrome (XXY) is an example of chromosomal aneuploidy that can readily be diagnosed by:
Karyotyping
If a gene is expressed within human liver cells, which of the following cells can be used to create a cDNA library?
Liver
Hemophilia A and hemophilia B have nearly identical phentoypes, but they result from a mutation in different genes on the X chromosome. This is an example of:
Locus heterogeneity
A 47, XXY karyotype may be caused by the non-disjunction of ________
Meiosis II in either parent
Which is true in connection with the spermatogenesis?
Meiosis is arrested at the first meiotic propohase
Which statement is NOT true about X and Y chromosomes?
Most of X and Y chromosomes located genes are related to gonadal and genital development.
A person with two or more different cell lines originating from a single zygote is called a:
Mozaic
Monozygotic twins showed 45% concordance, dizygotic twins showed 15%. What is true about the inheritance?
Multifactorial
Which type of inheritance results in continuous variation - often bell shaped curve - because genes at many loci are involved?
Multifactorial
Which of the following would eliminate X linkage as a possible mode of inheritance? An affected female has an affected mother X linked b. An affected female does NOT have an affected mother fathercouldhave giventheX c. An affected female has an affected father d. An affected female does NOT have an affected father fathercangive the X mothercouldhavegiventheX e. None of the above
Non of the above
Southern blotting is:
Non-radioactive DNA restriction fragments, separated by electrophoresis and blotted onto a membrane filter, is tested for hybridization with radioactive gene-specific probe of either RNA or DNA.
A point mutation that changes a codon specifying an amino acid into a stop codon is called a:
Nonsense mutation
Which technique would be most suitable for testing the hypothesis:Treating an estrogen-responsive cell line with estrogen gives a five-fold increase in the level of a specific mRNA with a length of 1800 nucleotides
Northern blotting
Which is not true for the structural chromosome aberrations?
One or more extra copy of chromosome is in the cell
If you examine a pedigree showing the transmission pattern of mitochondrial gene mutation, which of the following statements would be FALSE?
Only females will express the trait
From whom did a male with red-green color blindness inherit the defective allele?
Only from his mother
Question about Y-linked inheritance:
Only sons
What is it: Environmental factors lead to the same clinical phenotype as do the genetic factors?
Phenocopy
Which of the following identifies NOT correctly the mode of inheritance for the given genetic disease? (A eller E?)
Phenylketonuria - X - Linked recessive
Which of the following represents the best description for the movement of a fragment of the short arm of chromosome 6 to the long arm of chromosome 8 and concurrently, moving the fragment that should have been on the long arm of chromosome 8 to the short arm of chromosome 6?
Reciprocal translocation
Ectrodactyly is an autosomal dominant trait that causes missing middle finger (lobster-claw malformation). A grandfather and grandson both have ectrodactyly, but the intervening father has normal hands by X-ray. Which of the following terms would most appropriately apply to the trait in this family?
Reduced penetrance
Which one is NOT a length mutation?
SNP
Which cells are haploid in the process of spermatogenesis?
Secondary spermatocytes, spermatids
Ana's dad developed in his thirties a disease caused by genes carried by his mitochondria. Ana is 20 years-old and she is worried that she may have inherited the same disease. What can you tell Ana?
She should not worry because mitochondria are inherited maternally
The horn length of unicorns ranges from 45cm to 102 cm. When the horns of hundreds of unicorns are measured, the distribution forms a bell (Gaussian) curve. These data indicate that horn length in unicorns is controlled by
Single gene with different expressivity
During anaphase II (meiosis II)
Sister chromatids separate and migrate towards opposite poles
Which of these statements about the difference between mitosis and meiosis is true?
Sister chromatids separate during mitosis and meiosis II, but not during meiosis I
A girl has a brother with fragile X and wants to know if she carries the gene. What is the best way
Southern blot
What does it mean normal karyotype?
Species / individual specific number of chromosome
In vitro DNA synthesis requires the activity of _________
Taq polymerase
Genes of which of the following are coded on the Y chromosome:
Testis development
Which statement is TRUE for the cell cycle?
The DNA content of the cell is duplicated before mitosis
What is true for the chromosomes?
The DNA sequence of the two sister chromatids are identical
Which of the following observations is the strongest evidence for an important genetic component in the causation of type-1 diabetes mellitus (IDDM)?
The concordance rate in monozygotic twins is five times that in dizygotic twins
Pleiotropy refers to
The control of more than one trait by a single allele
In people with sickle cell disease the red blood cells breakdown, clump, and clog the blood vessels. The broken cells accumulate in the spleen. Among other things this leads to physical weakness, heart failure, pain, brain damage and spleen damage. Affected individuals become paralyzed and can develop rheumatism, pneumonia and other diseases and kidney failure. This is an example of:
The pleiotropic effects of the sickle cell allele
The number of chromosomes in a zygote is
The same as in a skin cell half
Which of the following statements regarding mutations causing Huntington Disease is FALSE?
The trinucleotide repeats are located within the 3' untranslated region of the Huntingtin gene.
RLFPs have been tremendously useful for genomic mapping studies because:
They are not restricted to genes, and are abundantly scattered throughout the genome
A human genetic defect that is caused by non-disjunction of sex chromosome is
Turner syndrome
There are three types of alleles denoting blood type: I^A, I^B and I^O. How many of these alleles does a typical person have?
Two
In a population expressing five different alleles for a particular gene, how many alleles may be present in each diploid organism in the population?
Two (One maternal + one paternal)
What is the function of Anaphase promoting complex?
Ubiquitin ligase
Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human's genes?
Use polymerase chain reaction
How can archeologist obtain enough DNA from unearthed human bones?
Use polymerase chain reaction
DNA endonuclease ENZ1 and ENZ2 both found in human (NOT in chimpanzee)
a. ENZ1 bacteria human and ENZ human
What is true about the stages in meiosis?
a. Pachytene - recombination / crossing over
26. In a group of 100 women with the genotype for widow's peak in the hairline, only 87 actually exhibited the trait. This is an example of
a. Reduced penetrance
DNA endonuclease makes:
a. Sticky ends
In the position of alanine we put glutamine, this is:
a. Substitution
How many genes cause Sickle cell anemia?
a. Two genes Sickle cell trait
Polyploidy refers to
an individual with complete extra sets of chromosomes
Find the genetic disorder and protein mismatch
c. Duchenne muscular dystrophy - myosin
Which cytoskeletal component play a crucial role in cytokinesis?
d. Actin and myosin filaments
Choose the correct statement for the M-phase
d. At the beginning of prophase the nuclear envelope disintegrates
A person has 3 barr bodies, what is true?
d. Has 4 chromosome X
Some mutations have been found that are expressed differently depending on the set of the parent the gene is passed through. This is called _______
imprinting
During the mitosis the spindle fibers connect to the:
kinetochores
human female is born with ________ cells in the primordial follicles of her ovaries
oogonia
Male pattern baldness is a ______ trait.
sex-influenced
Which type of chromosome abnormality is characteristic for the centric fusion?
structural aberration
