77 terms

Genetics Final HW 7-13

1) In Drosophila, sex is determined by a balance between the number of haploid sets of autosomes and the number of

A) telomeres
B) centromeres
C) X chromosome
D) Y chromosome
E) Nucleolar organizers
2) Which chromosomal condition leads to Klinefelter syndrome?

A) 47, XXY
B) 47, 21+
C) 45, X0
D) 47, XYY
E) Triploidy
3) A recessive gene for color-blindness is located on the X chromosomes in humans. A woman with normal vision (her father is color-blind) marries a color-blind male. What is the likelihood that their first son will be color blind?

A) 25%
B) 0%
C) 100%
D) 75%
E) 50%
4) Hemophilia is caused by a sex-linked recessive gene. If a man with hemophilia marries a normal woman (whose father has hemophilia), what is the probability that they will have a daughter with hemophilia?

A) 1/8
B) ½
C) ¼
D) 1/16
E) ¾
5) For an individual with the XXY chromosomal composition, the expected number of Barr bodies is,

A) two
B) one
C) zero
D) variable
E) three
1) Normally in humans, all the sons of a female homozygous for a sex linked recessive gene will inherit the trait. T/ F
2) Sex-influenced genes are those which cause males to be males and females to be females. T/ F
3) In Drosophila, sex is determined by the ratio of the number of X chromosomes to the number of haploid sets of autosomes. T/ F
4) An individual with Turner syndrome has one Barr body. T/ F
5) Dosage compensation is accomplished in humans by inactivation of the Y chromosome. T/ F
1) When an organism gains or loses one or more chromosomes but not a complete haploid set, the condition is known as;

A) polyploidy
B) euploidy
C) aneuploidy
D) triploidy
E) Trisomy
2) Cri-du-chat syndrome has a genetic composition designated as,

A) 45, X
B) Heteroplasmy
C) 46, 5p-
D) Triploidy
E) Trisomy
3) A genomic condition that may be responsible for some forms of fragile-X syndrome as well as Huntington's disease, involves

A) plasmids inserted into the FMR-1 gene
B) various lengths of trinucleotide repeats
C) multiple breakpoints fairly evenly dispersed along the X chromosome
D) multiple inversions in the X chromosome
E) single translocations in the X chromosome
4) Recently, a gene located on chromosome 3 in humans, FHIT has been shown to be associated with

A) cancer
B) Huntington's disease
C) Mad-cow disease
D) Klinefelter syndrome
E) XYY/ XY mosaicism
5) In Trisomy 21 or Down syndrome, although there is reduced fertility in both sexes females are more fertile than males. Assume that children are born to female with Down syndrome and a normal male. What proportion of children would be expected to have Down syndrome?

A) 1/3
B) 2/3
C) All
D) None
E) ½
1) Nondisjunction is considered as a major cause of aneuploidy. T/ F
2) Familial Down syndrome can be caused by a translocation between chromosome 1 and 14. T/ F
3) A deletion may set up a genetic circumstance known as overdominance. T/ F
4) A pericentric inversion includes the centromere. T/ F
5) Assume that an organism has a diploid chromosome number of 14. There would be 56 chromosomes in a tetraploid. T/ F
6) A position effect occurs when a gene's expression is altered by virtue of a change in the position. Position effects occur with inversions and translocations. T/ F
7) rDNA in eukaryotes is typically redundant. T/ F
1) Which of the following organelles are involved in the general category of organelle heredity?

A) mitochondria and chloroplasts
B) R factors
C) Lysosomes and peroxisomes
D) Factors and episomes
E) Golgi and rough endoplasmic reticulum
2) The term heteroplasmy refers to which of the following?

A) cells with a variable mixture of normal and abnormal organelles
B) heterozygous individuals with more than one gene pair involved
C) conditions where the germ plasm is a mixture of dominant and recessive genes
D) a circumstance that is homologous to incomplete dominance
E) various stages of development of mitochondria and chloroplasts
3) One explanation for organelle inheritance is that

A) Mitochondria and chloroplasts lack DNA and are therefore dependent on the maternal, cytoplasmic contributions.
B) Mitochondria and chloroplasts have DNA that is subject to mutation
C) Organelles such as mitochondria are always wild-type
D) Chloroplasts are completely dependent on the nuclear genome for components
E) None of the above
1) Mitochondrial mutations are passed equally to offspring by both males and females. T/ F
2) It is safe to say that a maternal effect is caused by the genotype, not the phenotype, of the parent producing the egg. T/ F
3) tRNAs and rRNAs are known to be encoded by mitochondrial DNA. T/ F
1) The basic structure of a nucleotide includes the following components;

A) amino acids
B) tryptophan and leucine
C) nitrogenous base, sugar and phosphate
D) mRNA, rRNA, and tRNA
E) phosphorous and sulfur
2) Reverse transcriptase is an enzyme found in association with retroviral activity. It has the property of

A) synthesis of DNA from an RNA template
B) synthesis of RNA from a DNA template
C) requiring no template
D) translation
E) most lysozymes
3) Considering the structure of double-stranded DNA, what kind of bonds hold one complementary strand to the other?

A) ionic
B) covalent
C) van der Waals
D) hydrogen
E) hydrophobic and hydrophilic
4) In a DNA structure, covalently arranged combination of a deoxyribose and a nitrogenous base would be called a

A) Nucleotide- nitrogenous base + sugar+ phosphate
B) ribonucleotide
C) monophosphate nucleoside
D) oligonucleotide
E) nucleoside - nitrogenous base + sugar
5) If 15% of the nitrogenous bases in a sample of DNA from a particular organism is thymine, what percentage should be cytosine?

A) 15%
B) 30%
C) 70%
D) 35%
E) 40%
6) Which of the following is true regarding the nucleotide composition of DNA?

A) A = C
B) A = G and C = T
C) A + C = G + T
D) A + T = G + C
E) Both B and C are true
7) Which of the following clusters of terms accurately describes DNA as it is generally viewed to exist in prokaryotes and eukaryotes?

A) double-stranded, parallel, (A + T)/ (G + C) = variable, (A + G)/ (C + T) = 1.0
B) double-stranded, antiparallel, (A + T)/ (G + C) = variable, (A + G)/ (C + T) = 1.0
C) single-stranded, antiparallel, (A + T)/ (G + C) = 1.0, (A + G)/ (C + T) = 1.0
D) double-stranded, parallel, (A + T)/ (G + C) = 1.0, (A + G)/ (C + T) = 1.0
E) double-stranded, antiparallel, (A + T)/ (G + C) = variable, (A + G)/ (C + T) = variable
1) In RNA, uracil is present instead of guanine (in DNA). T / F
2) Chargaff's rule states that A = T and G = C. T / F
3) In DNA, strings of nucleotides are joined together by hydrogen bonds. T / F
4) Cytosine, thymine and uracils are purines. T / F
5) B-DNA is the most prevalent and stable DNA structure. T / F
6) Heat or alkali can be used to denature DNA. T / F
1) DNA polymerase III adds nucleotides

A) to the 3' end of the RNA primer
B) to the 5' end of the RNA primer
C) in the place of the primer RNA after it is removed
D) to both ends of the RNA primer
E) to internal sites in the DNA template
2) Structures located at the ends of the eukaryotic chromosomes are called

A) centromeres
B) telomerase
C) recessive mutation
D) telomeres
E) permissive mutation
3) Which cluster of terms accurately reflects the nature of DNA replication in prokaryotes?

A) fixed point of initiation, bidirectional, conservative
B) fixed point of initiation, unidirectional, conservative
C) random point of initiation, bidirectional, semiconservative
D) fixed point of initiation, bidirectional, semiconservative
E) random point of initiation, unidirectional, semiconservative
4) DNA polymerase I adds nucleotides

A) to the 5' end of the primer
B) to the 3' end of the primer
C) in the place of the primer RNA after it is removed
D) on single-stranded templates without need for an RNA primer
E) in a 5' to 3' direction
5) Unwinding of DNA helix involves the following set of enzymes;

A) Helicase and DNA polymerase III
B) DnaA and SSBP
C) Helicase and SSBP
D) DNA polymerase I and III
E) Helicase and primase
1) DNA replicates conservatively, which means that one of the two daughter double-helices is 'old' and the other one is 'new'. T/ F
2) During replication, primase adds a short chain of DNA primer. T/ F
3) Replication of DNA occurs in the 5' to 3' direction; that is, new nucleoside triphosphates are added to the 3' end. T/ F
4) A characteristic of the aging cells is that their telomeres become very short. T/ F
5) A nucleosome is a structure associated with the nuclear membrane and associated with cellular transport. T/ F
6) DNA gyrase is responsible for keeping the uncoiled strands apart. T/ F
7) Telomerase is an RNA containing enzyme that adds telomeric DNA sequences onto the ends of linear chromosomes. T/ F
1) Viral chromosomes exist in a variety of structures and can be made up of the following;

A) Protein- or lipid-coding sequences
B) DNA only
D) RNA only
E) DNA, RNA or protein
2) In E.coli, the genetic material is composed of

A) Circular, double-stranded DNA
B) Linear, double-stranded DNA
C) RNA and protein
D) Circular, double-stranded RNA
E) Polypeptide chains
3) Eukaryotic chromosomes contain two general domains that relate to the degree of condensation. These two regions are

A) Heterochromatin and euchromatin
B) Uniform in the genetic information they contain
C) Separated by large sketches of repetitive DNA
D) Each void of typical protein-coding sequences of DNA
E) Void of introns
4) In human chromosomes, satellite DNA sequences of about 170 base pairs in length are present in tandem arrays of up to 1 million base pairs. Found mainly in centromere regions, they are called

A) Telomeres
B) Primers
C) Alphoid families
D) Euchromatic regions
E) Telomere-associated sequences
5) In addition to highly repetitive and unique DNA sequences, a third category of DNA sequences exist. What is it called and what types of elements are involved?

A) Composite DNA, telomeres and heterochromatin
B) Dominant DNA, heterochromatin and euchromatin
C) Multiple gene family DNA, hemoglobin and 70s RNA
D) Moderately repetitive DNA, SINEs, LINEs and VNTR
E) Permissive DNA, centromeres and heterochromatin
6) Chromatin of eukaryotes is organized into repeating interactions with protein octomers called nucleosomes. Nucleosomes are composed of which class of molecules?

A) Glycoproteins
B) Histones
C) Lipids
D) H1 histones
E) Nonhistone chromosomal proteins
7) Supercoiling relies on the enzyme

A) Helicase
B) DNAse
C) Topoisomerase
D) DNA polymerase I
E) Primase
1) Telomerase is an enzyme involved in the replication of the ends of eukaryotic chromosomes. T/ F
2) In contrast to euchromatin, heterochromatin contains more genes and is earlier replicating. T/ F
3) Viral genomes are always either double-stranded DNA or single-stranded RNA. T/ F
4) Polytene chromosomes are unique because they are composed of a large number of identical DNA strands. T/ F
5) Presence of heterochromatin is characteristic of prokaryotic chromosome. T/ F
1) Some restriction endonucleases produce 'sticky' ends. What makes an end sticky?

A) blunt ends
B) single-stranded complementary tails
C) poly-A sequences
D) 5' cap
E) Interference
2) List two especially useful characteristics of cloning vector

A) high copy number and antibiotic-resistance gene
B) virulence and lysogenecity
C) ability to integrate into host chromosome and cause lysis of the host cell
D) nonautonomous replication and transposition
E) reverse transcriptase and ligase activity
3) Vectors such as pUC18 contain a large number of restriction enzyme sites clustered in one region. What is that site called?

A) palindrome
B) consensus sequence
C) polylinker
D) beta-galactosidase
E) complementation
4) In a southern-blot, one generally

A) hybridizes filter-bound DNA with a DNA probe
B) hybridizes filter-bound RNA with a DNA probe
C) examines amino acid substitutions with radioactive probe
D) cleaves RNA with restriction endonuclease
E) ligates DNA with DNA ligase
5) ddNTPs are used in which of the following biochemical reaction?

A) restriction digestion
B) DNA sequencing
C) Electron transport
E) Plaque hybridization
6) Taq polymerase, a heat-stable DNA polymerase, is used in PCR, because

A) each PCR cycle includes a 'hot' (95 degree C) denaturation phase, that allows the primer to anneal to the target DNA
B) each PCR cycle includes a 'hot' (95 degree C) denaturation phase, that sterilize the culture
C) each PCR cycle includes a 'hot' (95 degree C) denaturation phase, that activates the Taq polymerase
D) each PCR cycle includes a 'hot' (95 degree C) denaturation phase, that separates the hydrogen bonds which hold the strands of DNA together
E) A and C are correct
7) ddNTP lacks ..............at the ........end.

A) methyl group, 3'
B) OH group, 3'
C) OH group, 5'
D) Carboxyl group, 3'
E) None of the above
1) To isolate a bacterium with a plasmid that carries a desired DNA fragment along with an ampicillin-resistance gene; we should grow the bacteria in a medium that contains ampicillin. T / F
2) A common term for a plasmid or other DNA element that serves as a cloning vehicle is vector. T / F
3) In a typical PCR, primers are used to cleave specific regions of the DNA template T / F
4) Some restriction endonucleases produce sticky ends, while others produce blunt ends. T / F
5) In restriction mapping, map units are expressed as m.u. T / F