BIOL 300 progress test #3 and #4 final review

where would you expect to find a housekeeping gene, a gene that is transcribed at high levels in a cell?

euchromatin

which of the following best describes the features of histones?

Along a 10,000 bp segment of DNA, you expect to find twice as many histone protein H4, as histone protein H1.

which of the following correctly lists the levels of compaction in eukaryotes from the least compact to the most compact?

naked DNA, nucleosome, solenoid, loop domains, metaphase chromosome

What term describes a fruit fly that has a total of 7 chromosomes because it is missing one copy of chromosome 3?

aneuploid

if the haploid number for a plant species is 14, how many chromosomes are found in the somatic cell of a member of the species that is diploid, monosomic, trisomic, and tetraploid, respectively?

28, 27, 29, 56

Mice have 40 chromosomes (2n = 40). Suppose a cell undergoing mitosis experiences a chromosome nondisjunction of a single chromosome. What are the chromosome numbers in the resulting daughter cells?

One cell will be monosomic (2n-1 or 2n= 39), and the other will be trisomic (2n+1 or 2n= 41).

A boy with Klinefelter syndrome (47,XXY) is born to a mother who is phenotypically normal and a father who has the X- linked skin condition called anhidrotic ectodermal dysplasia. The mother's skin is completely normal with no signs of the skin abnormality. In contrast, her son has patches of normal skin and patches of abnormal skin.

Which parent contributed the abnormal gamete?

describe the meiotic mistake that occurred. Be sure to indicate in which division the mistake occurred.

explain the son's skin phenotype.

The father must have contributed the abnormal X-linked gene.

Non-disjunction must have occurred during meiosis I.

This son's mosaic phenotype is caused by X-chromosome inactivation, a form of dosage compensation in mammals.

Which of the following outcomes is not a consequence of polyploidy?

increased fertility

Which human condition is the result of a partial chromosome deletion of the terminal end of chromosome 5.

Cri du chat syndrome

The figure shows the structure of a series of fruit fly deletion mutants. The gap in each line represents the segment of the chromosome that is deleted in each mutant period stains that were heterozygous for each deletion mutation and a point mutation (A, B, C, D, E, and F) were created and analyzed for wild type (+) or mutant (-) phenotype. The results of the analysis are shown in the table.

C,E,A,F,B,D

A normal chromosomes and its homolog carrying an inversion are given. The dot represents the centromere.

Normal: ABC•DEFGHIJ

Inversion: abc•dgfehij

What type of inversion is present in what is the name of the structure that will form during synapsis?

Paracentric, inversion loop

normal chromosome, and its homolog carrying an inversion are given. The dot represents the centromere.

Normal: ABC•DEFGHIJ

Inversion: abc•dgfehij

If there a crossover between E and F, which of the following are recombinant gametes?

ABC•DEFGHIJ; abc•dgfehij

which of the following sets of gametes would result from adjacent-1 segregation in reciprocal balanced, translocation heterozygotes? (table)

set 1

although the most frequent forms of down syndrome are caused by a random error, nondisjunction of chromosome 21, down syndrome occasionally runs in families. Which of the following is the case of this form of familial down syndrome?

A translocation between chromosome 21 and another autosome, most often chromosome 14

Which of the following features is common to both DNA replication and transcription?

A sugar-phosphate bond is formed between the 3' hydroxyl and the 5' phosphate.

where would you expect to observe coupling of transcription and translation?

In the cytoplasm of prokaryotes

it has been recently determined that the gene for Duchenne muscular dystrophy (DMD) is over 2000 kb in length; however, the mRNA produced by this gene is only about 14 kb long. What is a likely cause of this discrepancy?

The entrance have been spliced out during mRNA processing using spliceosomes

in bacteria, what aligns with the shine-dalgarno sequence during translation initiation?

16S rRNA

During _______, the Shine-Dalgarno sequence of mRNA base pairs with the 16S rRNA in the small subunit in ________.

translation; prokaryotes

During ______, the RNA polymerase court enzyme in sigma subunit bind to the -10 consensus sequence (pribnow box) double-stranded promoter in _______.

transcription, prokaryotes

During transcription, enhancers bind activator proteins to form a protein "bridge" that bends DNA in both prokaryotes and eukaryotes.

Transcription, eukaryotes

A tRNA contains the anticodon 3'-GAU-5'. This tRnA would pair with which mRNA codon and carry which amino acid? (Table)

5'CUA-3', which corresponds to the amino acid leucine.

In the unlikely event that a tRNA has been changed with the wrong, amino acid, what high Fidelity enzyme is likely to blame?

Aminoacyl synthetase

The TATA box is an important conserved sequence with a gene. What is its primary function?

The TATA box is the principal binding site for transcription factors in most eukaryotic promoters. It is located upstream of the transcriptional start site.

which of the following codons would have no third base "wobble" because it lacks synonymous codons? (Table)

UGG

in the presence of glucose, where is the lac repressor bound?

lacO

in partial diploid of the genotype I-P+O+Z-Y+ / I+P-O+Z+Y+, synthesis of

B-galactosidase will be inducible and permease will be inducible

The following hypothetical genotypes have genes A, B, and C corresponding to lacI, lacO, and lacZ, but not necessarily in that order. Data in the table indicate whether b-galactosidase is produced in the presence of an absence of inducer for each genotype. Use this data to identify the correspondence between A, B, and C and LacI, lacO, and lacZ genes. (table)

A= lacO, B=lacZ, C=lacI

and positive control of several sugar-metabolism-related operons, the catabolite activator protein (CAP) binds to DNA to stimulate transcription. What causes an increase in CAP?

decrease in glucose and increase in cAMP

Typically, methylation of nucleosome N-terminal tail leads to

tighter packaging of the chromatin and reduced transcription

which regulatory sequences are bound by activator proteins and associated co-activator proteins to form a protein bridge that bends the DNA and links the complete initiation complex at the promoter to the activator-coactivator complex, ultimately causing an increase in transcription?

enhancer

When CpG islands are unmethylated,

chromatin in the promotor region is open, allowing access by transcription factors and RNA polymerase

Prader-Willi syndrome is a genetic disorder involving a partial deletion of chromosome 15q on the paternal chromosome. when both copies of a gene (or chromosome) are functional but only one is expressed, this is an example of _________.

genomic imprinting

many types of cancer are known to over-express the receptor protein tyrosine kinase. Which molecular technique can be used to reduce expression of tyrosine kinase in cell culture?

RNAi

5'-ACG___________-3' is half of a palindromic restriction site. What is the complete sequence?

5'ACGCGT-3'

what size fragments would you expect from an EcoRI / Xhol double digest of the plasmid below? (table)

3 kb, 3.75 kb, 4.25 kb

Assume that a plasmid (circular) is 3200 base pairs in length and has restriction sites at the following locations: 400, 700, 1400, and 2600. give the expected sizes of the restriction fragments following complete digestion.

300, 700, 1000, 1200

A DNA fragment is introduced into the lacZ jean of a plasmid, which also contains and ampicillin resistance gene. What is the appearance of bacteria transformed with this plasmid if they are spread on plates containing ampicillin, and Xgal?

White colonies that are resistant to ampicillin

which of the following is true of the sequences found in DNA libraries from human tissue?

those in a muscle cDNA library should all be present in a brain genomic library

Which of the following statements is false regarding gene therapy?

The integration of a transgene into the genome of the target, sell by viral vector, is not permanent, and therefore will require repeated treatments.

Which of the following is not an assumption of the hardy Weinberg equilibrium?

Natural selection operates

DNA from 100 unrelated people was digested with the restriction enzyme BamHI, and the resulting fragments were separated, and probed with a sequence for a particular gene. 3 fragment lengths that hybridized with the probe were observed- namely 4.0, 6.0, and 8.0kb- where each fragment defines a different restriction, fragment allele. The accompanying illustration shows the gel patterns observed. what's the allele frequency of the 4.0kb allele? (table)

0.25

The incidence of phenylketonuria (PKU), and autosomal recessive genetic disorder, is approximately 1 in 4,500 in Ireland. Assuming hardy Weinberg equilibrium, what is the frequency of PKU carriers in Ireland?

2.9%

The incidence of Tay Sachs, an autosomal recessive disorder, is approximately 1 in 3,500 in a certain population. Assuming hardy Weinberg equilibrium, what is the probability that Sarah, who is phenotypically normal with no family, history, and Tom, who, despite having it affected sister, is phenotypically normal, like his parents, will have a child with Tay Sachs?

0.55%

The most common form of color blindness, known as red - green blindness, is an X-linked recessive trait affecting about 8% of the male population in the United States. What percentage of females would you expect to be red - green color blind?

0.64%

during the University of Nevada, Reno, blood donation campaign, the frequencies of alleles determining the ABO. Blood groups were determined to be 0.70 for IO, 0.2 for IA, and 0.1 for IB. assuming random meeting, what is the expected frequency of blood type O?

0.49

you are studying ABO blood groups, and you know that 2.25% of the population has genotype IBIB and 30.25% of the population has type O blood. What is the expected frequency of blood type A?

42%

A researcher studying a newly discovered gene that causes increase body weight and domesticated chickens. Any mainland population, the frequency of the A-1 allele is 0.2, for this gene with two wheels. If 100 of these mainland chicken are transported on a ship to an isolated island with a population of 200 A1A1 chickens, 400 A1A2 chickens, and, 400 A2A2 chickens, what would the frequency of the A1 allele in the admixed population?

0.382

cheetahs exhibit significant inbreeding, and lots of heterozygosity, due to overhunting and lots of habitat experienced at some point in the revolutionary history, which genetic mechanism occurs when a large population of substantially reduced at random, acting independently of natural selection?

bottleneck effect

A population of 1000 Jeffrey pines from mount rose, has been genotyped at a gene involved in resistance to blister rust. the genotypes are:

• R1R1 350

• R1R2 400

• R2R2 250

what is the chi-square (x^2) value and do you reject your chance hypothesis? (table)

36.8; reject