269 terms

Genetics old final questions

If a tetraploid with 28 chromosomes: 4N=28 chromosomes. A hexaploid has how many chromosomes?
42, 6N=42
When an organism gains or loses one or more chromosomes but not a complete haploid set
Hershey and Chase experiment offered evidence in support of DNA being genetic material. This made use of these radioactively labeled components:
Phosphorous (DNA) and sulfur (proteins)
Griffith's transforming element was DNA was the major conclusion of who's experiment?
Hershey and Chase
If the transforming element described by Avery, MacLeod, and McCarty had been RNAse sensitive, this would have indicated that ___ was the genetic material
RNA (RNAse destroys RNA)
Cultivated American cotton is thought to have arisen from a _____ event
The salivary glands of water gliders often contain cells with thousands of chromosomes. This condition is termed ____
Metacentric chromosomes are frequently formed from two acrocentric chromosomes by the process of _____
centric fusion
In two point mapping, the presence of both dominant alleles on one homolog is termed ____
coupled configuration (AA, repulsed Aa)
In chromosome location studies with fruit flies, females are normally selected as the heterozygous parent. This is because....
crossing over is inhibited in male fruit flies.
Trisomy 21 is commonly called
Down's Syndrome
Monosomy X is commonly called
Turner's Syndrome
Cri-du-chat is a
terminal deletion
Triploidy is represented by...
Monoploidy is represented by....
2n+3 is called a
Centromere involved
No centromere involved
XXXX represents a...
4N represents a....
Dominant in males, recessive in females.
Sex influenced
Human color blindess is an example of a ..... trait
sex linked
X and Y are....
sex chromosomes
Chromosomes that don't differ between the sexes
the time during mitosis when sister chromatids separate
haploid cells specialized for reproduction
one of the identical halves of a replicated chromosome
Any variation in chromosome number that does not involve whole sets of chromosomes is termed....
A theoretical measure of the number of independent genomic units that would be represented in or contribute to the next gene pool is termed...
effective population size
The most extreme form of inbreeding possible in sexually reproducing organisms is:
self fertilization
familial down's syndrome is caused by a chromosome.....
Improvement of humans through selective breeding was originally termed.... and used by Hitler
Hardy weinberg equilibrium cannot have a genotypic frequency of the heterozygotes greater that.....
endopolyploidy is a condition often observed in
liver cells, water gliders
If 2 gene loci are on nonhomologous chromosomes, alleles at these loci are expected to assort independently. T/F
A paracentric inversion includes the centromere. T/F
False (pericentric includes)
DNA has no sulfur, proteins have no phosphorous. T/F
An individual with Turner Syndrome has no barr bodies. T/F
The transforming principle discovered by griffith was RNA. T/F
False (DNA)
Assume a species has a diploid chromosome number of 24. The term applied to an individual with 25 chromosomes should be triploid. T/F
False (12N+1)
Assume that an organism has a diploid chromosome # of 14. The term applied to an individual with 28 chromosomes would be tetraploid. T/F
Familial Down's syndrome can be caused by a translocation between chromosomes #1 and #14. T/F
False (that's trisomy 21)
An individual with Patau's syndrome would be called a monosomy. T/F
False (Trisomy. Monosomy not possible in Auto)
When considering the structure of DNA, we would say that the complementary strands are parallel. T/F
False (antiparallel)
Hershey and Chase used labeled DNA and protein to determine that DNA is the genetic material in bacteria. T/F
G and C are present in both DNA and RNA. T/F
Thymine is a pyrimidine base. T/F
A section of DNA with the sequence TTTTTTTT would be expected to be more thermally stable than a section with GGGGGGGG. T/F
False (G is most stable)
The B form of DNA is a left handed helix. T/F
False. (Z is only left form)
Both acentric and dicentric chromatids can result from crossovers with inversion loops. T/F
Double stranded DNA that contains 200 bp would be approximately 480 A long. T/F
The alleles that we used in the Molecular Genotyping lab exercise were from repeated regions of DNA called microsatellites. On a CoT curve, these are called HR regions. T/F
The base content of a DNA sample is found to be: A=31%, G=31%, T=19%, C=19%. The DNA in this sample is single stranded. T/F
The maternal age effect was first associated with Turner's syndrome.
False (Down's syndrome)
Considering the structure of double-stranded DNA, what kind of bonds hold one complementary strand to the other?
Hydrogen bonds
When 2 genes fail to assort independently, the term normally applied is....
The human genome contains fewer than ____ genes.
Telomerase adds nucleotides to the __ end of the __ strand of DNA
3', old
Uracil is an example of a ____ and is found in ____.
pyrimidine, RNA
If a dsDNA molecule has 1,000 base pairs, how long is it?
3,400 A
If a dsDNA molecule has 1,000 base pairs, how many turns of the spiral would you expect?
100 (10 bp/turn)
Which genome characteristics would likely be representative of an organism found inhabiting the hot springs that supply water to Roman spas in Bath, England?
% GC would be larger than % AT
If a dsDNA molecule has 12% adenine, how much Cytosine would be found? Who's rule is this?
38%, Chargaff's
Chain termination sequencing of DNA works because ______ are included in small amounts in each reaction tube
If a peptide occurs in one of your cells that is 50 aa long, what is the minimum number of nucleotides that would have been required for efficient translation?
154 (50 aa * 3 codons each= 150+3 stop codons + 1G=154)
An inactivated X chromosome (Barr body) is an example of _____
facultative heterochromatin
AUG is an example of a ____
start codon
required to initiate transcription
complimentary to antisense
Sense strand
Adds poly a tail
poly a polymerase
catalyzes amino acid addition to tRNA
Amino-acyl synthetase
Synthesizes RNA
RNA polymerase
component of ribosome
carrier of amino acids
responsible for intron removal
SNURP (Splicesome)
Met in P site is a ....
start codon
degrades RNA (function)
"Cap" nucleotide
added post-transcriptionally
200+ adenines
found only in the nucleus
catalyzes peptide bond
Peptidyl transferase
reduce supercoiling of DNA
unzips DNA (unwinds H-bonds)
enzyme that fills the gap
300 A wide
100 A wide
A length of a double stranded DNA that is 2000 bp long would have how many nucleosome structures?
10 (dsDNA=150 bp, linker DNA=50 bp so 200 bp per nucleosome, 2000/200=10 nucleosomes)
DNA replication occurs in the 5' to 3' direction, that is, new nucleotides are added to the 3' end. T/F
A nucleosome is a structure associated with the nuclear membrane. It helps maintain a stable relationship between the extracellular matrix and the membrane itself. T/F
False (It helps condense DNA)
DNA replicates semiconservatively, meaning of the two daughter double-helixes, one is old and the other is new. T/F
False (DNA replicates semi-conservatively and conservative is old-old)
In contrast to euchromatin, heterochromatin contains more genes and is earlier replicating. T/F
False (heterochromatin contains no genes and is non-coding)
Telomerase is an enzyme involved in the replication of the ends of eukaryotic chromosomes. T/F
When one speaks of a 5' cap, one is describing the addition of a base, usually thymine, to the 5' end of a completed peptide. T/F
The genetic code is non-overlapping, meaning that, assuming "standard translation", a given base participates in the specification of one and only one amino acid. T/F
The primary structure of a protein is composed of the sequence of amino acids in that protein. T/F
During replication, primase adds a DNA primer to RNA. T/F
A 3' Poly-A tail and a 5' cap are common components of prokaryotic RNA's. T/F
False (eukaryotic)
Proteins are composed of strings of nucleotides connected together by 5'-3' phosphodiester bonds. T/F
False (RNA)
The triplet AUG is commonly used as a start codon during translation. T/F
rDNA is that portion of a genome which is involved in the production of ribosomal RNA. T/F
An intron is a section of RNA which gets spliced out. T/F
Unambiguous refers to the fact that the third position of many codons can vary without changing the amino acid the code for. T/F
FALSE (degenerate)
Human Barr bodies are termed facultative heterochromatin. T/F
Dideoxynulceotide is important in DNA sequencing. T/F
The term peptidyl transferase relates to ....
peptide bond formation
What name is given to the 3 bases in a mRNA which bind to the anticodon of tRNA to specify an amino acid placement in a protein?
The genetic code is fairly consistent among all organisms. The term is called....
When considering the initiation of transcription, one often finds consensus sequences located in the region of the DNA where RNA pol binds. Which are the common consensus sequences?
Side groups of aa are typically grouped under which of the following?
Polar, nonpolar
One form of posttranslational modification of a protein includes:
removal or modification of terminal aa.
The secondary structure of a protein includes the following elements:
alpha helix and beta pleated sheet
Sequence of aa in peptide
Primary structure
3-D structure
tertiary structure
Oligometric proteins, more than 1 peptide chain
quarternary structure
What is the initiator triplet in prokaryotes and eukaryotes? What is aa coded for?
AUG, methionine
The lagging strand produced during DNA replication is caused by the....
5' to 3' polarity restriction of DNA polymerase
What enzyme functions to help unwind dsDNA during replication?
THe name of the protein structure that appears at the G2/M boundary and assists in the final condensation of chromosomes is called
Chromatin refers to a complex consisting of proteins and....
3 nucleotides taken together are termed a.....
In a cell with no uracil would replication, ribosome formation, and transcription occur?
Old parental strand of DNA and one new strand in each of the sister chromatids composes....
sister chromatids
During replication, ...... adds a short length of RNA to the new DNA strands.
Linkage and crossing over are......., linkage keeps genes......, crossing over ........ genes up.
opposite, together, mixes
Crossing over take place in ..... and is the exchange of genetic material between......
Prophase 1 of meiosis, non-sister chromatids
Arrangement in which the wild type alleles are found on one chromosome and mutant alleles are found on the other chromosomes is called.....or....configuration.
coupling, cis
The arrangement in which each chromosome contains one wild type and one mutant allele is called.....or .....configuration
repulsion, trans
Between genes of different chromosomes, arises from independent assortment in anaphase 1 of meiosis.
interchromosomal recombination
You can tell genes are linked if there are more......progeny than...... progeny
nonrecombinant, recombinant
The degree to which one crossover interferes with additional crossovers in the same region is called......
number of observed double crossovers/number expected double crossovers .........the equation for the____
coefficient of coincidence
1- coefficient of coincidence calculates....
When interference is complete and no double crossover is observed, the coefficient of coincidence is __ and the interference is ___
Chromosome where the centromere is in the middle and so the chromosome has two arms of equal length
centromere is displaced toward one end, creating a long arm and a short arm (in humans, short arm is p and long arm is q)
centromere is near one end, producing a long arm and a knob or satellite on the other end
the centromere is at or very near the end of the chromosome
The complete set of chromosomes possessed by an organism
Chromosome rearrangements, aneuploids, and polyploids are the three types of ......
chromosome mutations
Chromosome rearrangements alter the ____ of chromosomes.
In aneuploidy, the ____ of chromosomes is altered, one or more is added or deleted.
In polyploidy, one or more __ of chromosomes is added or deleted.
Mutations in which point of the chromosome has been doubled.
chromosome duplication
Type of duplication mutation where duplicated region is immediately adjacent to the original segment called a .....
tandem duplication
Type of duplication mutation where duplicated segment is located some distance from the original segment, either on the same chromosome or a different one, the chromosome rearrangement is called a ____
displaced duplication
Type of duplication mutation when the duplication is inverted
reverse duplication
Do duplications effect the phenotype?
The expression of a recessive mutation. An indication that one of the homologous chromosomes has a deletion
When a single copy of a gene is not sufficient to produce a wild type phenotype, it is said to be a ..........
haploinsufficient gene
When a chromosome is turned 180 degrees.
When an inversion takes place, the chromosome must break in __ places
Inversions that don't include the centromere are termed.....
paracentric inversions
Inversions that include the centromere are called.....
pericentric inversions
If a gene's position is altered by an inversion, it may be expressed at an inappropriate time or in inappropriate tissues. This is referred to as the....
position effect
Chromatid that has 2 centromeres, produced when crossing over takes place within a paracentric inversion.
dicentric chromatid
The 2 centromeres of the dicentric chromatid are frequently pulled........in mitosis or meiosis, breaking the chromosome
lacks a centromere, produced when crossing over takes place within a paracentric inversion
acentric chromatid
In anaphase one, the centromeres are pulled toward opposite poles and the two homologous chromosomes separate. This stretches the dicentric chromatid cross the center of the nucleus, forming a .....
dicentric bridge
entails the movement of genetic material between non homologous chromosomes within the same chromosome
Genetic material moves from one chromosome to another without any reciprocal exchange
nonreciprocal translation
genetic disease characterized by numerous fibrous tumors of the skin and nervous tissue, results from an autosomal dominant mutation.
The long arms of two acrocentric chromosomes become joined to a common centromere through translocation, generating a metacentric chromosome with two long arms and another chromosome with two very short arms
Robertsonian translocation
Robertsonian translocations are the cause of some cases of _____
Down syndrome
Chromosomes of cells grown in culture sometimes develop constrictions or gaps at particular locations called______, because they are prone to breakage under certain conditions
fragile sites
Disorder occurs from site on X chromosome, associated with mental retardation. It has been shown to result from a increase in the number of repeats of a CGG trinucleotide
Fragile X syndome
An increase or decrease in the number of individual chromosomes
Ends of genes are ___ rich. These regions allow the formation of hairpin loops which contribute to:___
GC, termination of transcription
The promotor region of a gene is used specifically to ____
start transcription
When something is said to be highly conserved, this means that it is similar between all life forms found on the planet. T/F
highly complex genomes often lack repetitive DNA sequences. T/F
Euchromatin is a ____ coiled region of a chromosome involved in ____
loosely, transcription
Replication occurs during the ____ phase of Mitosis.
Telomerase is an enzyme involved in replication of the ends of eukaryotic chromosomes. T/F
The 5'-3' polarity restriction of DNA polymerase during DNA replication produces the ____
lagging strand
Spliceosomes are found in the ____ and help to _____
nucleus, remove introns
Transcription produces:
The region of DNA that comprises what is traditionally called a gene is known as the ____
transcriptional unit
Telomerase is an enzyme involved in the replication of the ends of eukaryotic chromosomes. T/F
Enhancers are regulatory elements which serve as coordinators of gene transcription. T/F
The c-value paradox suggests that higher organisms have ____ DNA than they need to encode all essential genes
The model hypothesized to explain the condensation of DNA into chromosomes is termed the ____ model
Folded fiber
DNA replication results in____
sister chromatids
Cot curves provide information about the _____ of genomes
size, complexity
Anti-codons go in the ___to____ direction
Translation involves four steps:
tRNA charging, Initiation, Elongation, Termination
When reading frames are defined
TATA consensus sequences are involved in____
RNA polymerase is active in..........
Peptidyl transferase is active in.....
Three different RNAs are required for.....
Aminoacyl synthetase is involved in....
ribosomes are formed in...
Ligase is involved in...
RNA polymerase is involved in...
DNA polymerase is involved in....
Taylor, Woods, and Hughes discovered...
Gyrase is involved in....
Helicase is involved in....
G/C rich region is involved in.....
Lagging strand is involved in.....
antisense strand is involved in.....
mRNA is involved in......
RNA primer is involved in.....
Specific DNA sequences shared by genes to which proteins bind to coordinate gene activity is termed...
Structures located at the end of eukaryotic chromosomes are called .....
DNA of eukaryotes is organized into repeating interaction with protein octomers forming structures called nucleosomes. nucleosomes are composed of which class of molecules are called:
Each codon is thought to be unique for one and only one amino acid. The term associated with this property of genetic code is....
Metaphase chromosomes normally contain two general domains(bands) which relate to the degree condensation. These two regions are:
heterchromatin, euchromatin
Cot curves provide information about the size and complexity of the genomes. T/F
Transcription occurs in the....
Chromosomal regions which represent evolutionary vestiges of duplicated copies of genes that have underdone sufficient mutations to render them untranscribable are called.....
Centromeres are often listed as an example of constitutive heterochromatin. T/F
In addition to highly repetitive and unique DNA sequence, a third category of DNA sequences exists. It is called...
moderately repetitive DNA
The histone called ___ binds DNA to the nucleosome and is critical for the formation of the ____
H1, solenoid
Ratio for single dominant epistasis
Ratio for single recessive epistasis
Ratio for double recessive epistasis
Ratio for segregation
AaBb x Aabb ratio
Aabb x aabb
female rabbits are
male penguin is
Huntington's disease is caused by a ___ gene
dominant lethal
cock feathering is a ___ trait
A genetic trait is hypothesized to exhibit a simple dominant/recessive mode of inheritance. If 2 heterozygotes are crossed and 100 progeny produced, what expected numbers would you use to conduct a chi-squared test of this hypothesis?
75 dominant, 25 recessive
Black pelage of guinea pigs is a dominant trait, white is recessive phenotype. When two heterozygous black guinea pigs are crossed, what fraction of the black F2 offspring are expected to be heterozygous?
Of the couples attending PTA night at a local school, 12 couples report that they have 2 kids. How many of these couples would you predict to have two daughters?
Assume that curly wind and brown eye are both autosomal recessive alleles in fruit flies. If two heterozygous wild-type flies with both of these traits are mated, which of Mendel's principles would you use to predict the phenotypic ratios in the offspring?
segregation, independent assortment
As you learned in lab, Modes of inheritance have "signatures" that can help you identify them. For example, one signature for the classic dominant/recessive mode would be: a phenotype disappears in the F1 and re-appears in the F2 in a 3:1 ratio. T/F
One phenotype is never true breeding and when crossed yields a 2:1 ratio is a signature for......
recessive lethal
Plumage color in mallard ducks is dependent upon a single locus with 3 alleles. The alleles form a dominance series with R (restricted)-->M (mallard)-->D (dusky). What genotypic ratio would you expect from a RM x RD cross? What phenotypic ratio would you expect here?
1:1:1:1, 3:1
The theory that new organs and tissues form completely new (de novo) each generation is termed:
An individual with the genotype AabbCCDd could produce how many different types of gametes if meiosis were completed a large number of times?
Humans have 46 chromosomes in each somatic cell. How many autosomes does a child receive from her father?
In pocket gophers, gray coat color is produced by a recessive lethal allele. At a separate locus, green eye color is found to be dominant over brown. If two heterozygous gray, green eyed gophers are crossed, the final phenotypic ratio for the living progeny would be...
If two shepherd's purse plants are crossed and the phenotypic ratio in the progeny is found to be 15:1, the genotypes of the parents must have been
AaBb x AaBb
two traits affected by one locus illustrates
A decrease in the number of heterozygotes with a related increase in the number of homozygotes in a population is characteristic of ___
The syndrome resulting from a monosomy of the sex chromosomes is ___
The test used to determine if observed data agree with expectations, for example in linkage studies, is called ....
traits that involve many loci/continuous distributions are called .....
quantitative traits
Chromosome abberations that can occur from the exchange of DNA between two nonhomologous chromosomes are termed:
Classical Eugenics faced many problems, one of which was the most of the traits of interest were controlled by many genes. The genetic terms for these are.... traits.
Any change in the gene pool, such as a change in gene frequencies, over time can be termed .....
Most chromosome abberations arise de novo but some occur repeatedly in family lineages. One example is ..... syndrome
Familial Down's
The linkage arrangement in dihybrid in which the two dominant alleles are on one chromosome and their corresponding recessive alleles are on the homologous chromosome are termed....
Assume a cross is made between AaBn and aabb plants and all of the offspring are either AaBb or aabb. These results are most consistent with the following circumstance:
complete linkage
When an organism gains or loses one or more chromosomes but not a complete haploid set, the condition is known as....
In humans, the genetic basis for determining the sex "male" is accomplished by the presence of a portion of the ___ chromosomes
Klinefelter's syndrom in humans, which leads to underdeveloped testes and sterility is caused by this chromosomal condition:...chromosomes and ....
47, XXY
The condition known as William's syndrome in humans results in heart problems due to a defect in the elastin gene located on chromosome 7. The genetic cause of this syndrome is an ________
intercalary deletion
While the most frequent form of Down's syndrome is caused by a random error, Down's syndrome occasionally runs in families. The cause of this form of familial Down's is : a ____ between chromosomes __ and ___
translocation, 21, 14
What term is given to the genetic information carried by all reproductive members of a population?
gene pool
Environmental factors typically have the strongest influence on the inheritance of _____
continuous traits
____ is the only source of truly new variation in a population
Nondisjunction of the sex chromosome during meiosis I normally results in sperm with odd numbers of chromosomes. If these sperm fertilize normal haploid eggs, you could expect to observe offspring that were:
Monosomic, Trisomic
If color is controlled by additive alleles where A and B each contribute 1 dose of color, how many phenotypes would you expect from the cross AaBb x Aabb
More than one amino acid can be specified by given codon. T/F
Mutant genes, which when normal are involved in promoting the cell cycle are known as.....
Ends of genes are GC rich. These regions allow the formation of hairpin loops which contribute to....
termination of transcription
The amino acid that initiates a new peptide chain is brought to the ribosome by a charged tRNA. What amino acid does that tRNA carry?
The region of DNA that comprises what is traditionally called a gene is known as the...
transcriptional unit
Mutations that arise without known external cause are thought to be ..
Two genes with a 50% recombination frequency are.... map units apart
Centromeres of sister chromatids uncouple and chromatids separate during
anapase II
For an organism with a diploid number of 46 chromosomes, the per cell number of centromeres at metaphase of mitosis is....
The fundamental Mendelian process which involves the separation of contrasting genetic elements at the same locus would be called...
What is the name given to the three bases in a messenger RNA which bind to the anticodon of tRNA to specify the amino acid in a polypeptide chain?
Albinism, of the lack of pigmentation, is autosomal recessive in humans. Two parents with normal pigmentation have an albino child. What is the probability that their next child will be an albino girl?