BIO301 - Final Exam Study Guide

Prototroph

A bacteria that does not require any organic growth factors. Non-mutated.

R plasmid

A bacterial plasmid carrying genes that confer resistance to certain antibiotics.

Auxotroph

A bacterium that cannot grow on minimal growth media, due to its inability to synthesize necessary amino acids.

Clonal

A cancer that originates from a single cell (when one cancerous parent cell divides into two cancerous daughter cells).

Carcinogen

A cancer-causing mutagen

Mutagen

A chemical that causes DNA mutation.

Cancer

A disease characterized by uncontrolled cell division.

Tumor-suppressor gene

A gene that prevents cancerous growth.

Transformation

A living bacterial cell picks up genetic material from the environment.

Auxotroph

A mutant bacteria that cannot create certain amino acids on its own.

Oncogene

A mutant gene that is over-expressed and contributes to the formation of cancer.

Proto-oncogene

A normal, non-mutated gene that has the potential to become an oncogene.

-horizontal gene transfer from another species of bacterium -transduction via a bacteriophage -transformation from DNA in the environmentA

A patient is infected with a new strain of bacteria that is resistant to several different antibiotics. How could the resistance gene have entered the original, antibiotic-sensitive strain?

Ames test

A test in which special strains of bacteria are used to test for mutagens.

A reduction/turned off

A translocation that moves a gene from an area of euchromatin to heterochromatin would typically cause _____ in the expression of the gene.

Acutely Transforming Virus (ACT)

A type of virus that rapidly induces tumors in animals and and efficiently transforms cell sin culture.

Transduction

A virus infects a bacterium and then transfers some bacterial genetic material from that bacterium to another.

A) The person will definitely develop the cancer in their lifetime.

After genetic testing, a person is identified with an inherited mutation associated with a specific class of cancer. Which of the following is incorrect? A) The person will definitely develop the cancer in their lifetime. B) The person may pass the trait on to their offspring. C) The mutation is probably in a tumor-suppressing gene. D) The person is predisposed to the development of the cancer.

Carcinogen

An environmental agent that causes cancer.

80%

Approximately what percentage of cancers arise from somatic mutations?

Apoptosis

Caspases are active during which of the following?

Induced mutation

Cause/mutagen is known

Spontaneous mutation

Cause/mutagen is unknown

A, B, C, and D are all true

During conjugation, one gene (A) is found to transfer to the recipient bacteria 26 minutes following the start of conjugation, while a second gene (M) is found to transfer 37 minutes following the start of conjugation. A third gene (T) transfers 45 minutes following the start of conjugation. Based on this information, which of the following is true? A. Genes A and M have a genetic distance of 11 minutes. B. Genes A and T have a genetic distance of 19 minutes. C. Genes M and T have a genetic distance of 18 minutes. D. The order of the genes is A T M.

[5 minutes](azi)[15 minutes](thr)[20 minutes](bio)[O]

During conjugation, one gene (azi) is found to transfer to the recipient bacteria 5 minutes following the start of conjugation, while a second gene (bio) is found to transfer 40 minutes following the start of conjugation. A third gene (thr) transfers 20 minutes following the start of conjugation. Based on this information, draw a chromosome map of what order these genes might be in. INCLUDE DISTANCE IN MINUTES AND ORIGIN.

Huntington's disease. Wild type has 6-37 repeats of CAG sequences. However, if the gene codes for more than 37 (up to 100 repeats), it causes an overabundance of glutamine, which causes neurodegenerative disease.

Give an example of a Trinucleotide Repeat Expansion (TNRE) mutation. What is repeated, and what does it cause?

* No lactose/no glucose = negative regulation * lactose/no glucose = positive regulation

How is the lac operon regulated?

When lactose is present.

How/when is the lac operon derepressed (turned on)?

The genotypic frequency of heterozygous individuals

In the Hardy-Weinberg equation, what does the term 2pq represent?

Transversion

In the following sequence of DNA, the italicized base has been mutated. What type of mutation is this? 5' - G A T C T C C G A A T T - 3' original strand 5' - G A T C T C C C A A T T - 3' mutated strand

Horizontal gene transfer

In this type of gene transfer, DNA can be acquired from the same species or from a different species.

Clastogens

Mutagens that cause breaks in DNA (example: X-rays and gamma rays)

X New Mutation X Gene Duplication X Exon shuffling

New genetic variations may occur because of... (Check all that apply) * New mutations. * Gene duplications. * Exon shuffling. * Random genetic drift. * Darwinian selection.

Conjugation

One bacterium acts as a donor and transfers genetic material to a recipient cell.

Apoptosis

Programmed cell death

A) Loosening of the chromatin in that region of DNA.

Recruitment of histone acetyltransferase to a region of genomic DNA would most likely cause: A) Loosening of the chromatin in that region of DNA. B) Condensing of the chromatin in that region of DNA. C) Altering the types of histones in the nucleosomes of that region of DNA. D) B and C

Plasmids

Small circular pieces of bacterial DNA that are used as vectors in cloning experiments.

Genome maintenance

The cellular mechanisms that either prevent mutation from occurring, and/or prevent mutant cells from surviving or dividing.

Transformation

The conversion of a normal cell into a malignant cell.

D. deamination

The conversion of cytosine to uracil in DNA is an example of _____. A. tautomeric shifts B. None of the answers are correct. C. depurination D. deamination

Molecular profiling

The diagnostic process of determining the molecular changes that occur in individuals during disease.

Transversion mutation

The point mutation in which a purine is substituted for a pyrimidine, or vice versa.

Transition mutation

The point mutation in which a purine is substituted for another purine or a pyrimidine is substituted for another pyrimidine.

Tautomerization

The reversible change of of the location of hydrogen atoms in the base, causing incorrect base pairing.

Pharmacogenetics

The study or clinical testing of the interactions of genetic variations and drugs.

Personalized medicine

The use of information about a person's genotype and other clinical data in order to select a medication.

Missense mutation

This type of mutation changes a single amino acid in the protein.

Nonsense mutation

This type of mutation converts an amino acid codon to a termination codon.

Silent mutation

This type of mutation does not involve the change of the amino acid structure of the protein, due to codon degeneracy.

Frameshift mutation

This type of mutation involves the addition or deletion of nucleotides.

Neutral mutation

This type of mutation involves the change of a single amino acid. However, it does not have any noticeable effect on the protein.

False: Homologous recombination requires sequence similarity. If the DNA becomes incorporated randomly, this is known as nonhomologous recombination or illegitimate recombination.

True or False: During transformation, homologous recombination may occur if the sequence of the introduced DNA has no similarity to the host DNA.

False: it demonstrated TRANSFORMATION

True or False: Griffith's experiments with heat-killed IIIS and live IIR bacteria demonstrated transduction.

True

True or False: Restriction endonucleases are specific in the DNA sequences that they recognize.

False, germ cells.

True or False; Somatic cells are those that give rise to sperm and egg cells.

False

True or false: At equilibrium the allelic and genotypic frequencies of a population change over time.

True: they only affect the coding of the protein.

True or false: Nonsense mutations have no effect on transcription

Valine is transcribed instead of glutamic acid (missense mutation).

What amino acid is incorrectly transcribed from a mutant beta gene to cause sickle cell disease? What type of mutation is this?

When glucose is low, cAMP is high. When glucose is high, cAMP is low.

What are cAMP levels when glucose is low? What are cAMP levels when glucose is high?

Tumor suppressors inhibit the cell cycle and oncogenes stimulate the cell cycle.

What are the general ways that tumor suppressors and oncogenes act?

A) May increase or decrease the rate of transcription B) May disrupt the ability of the gene to be properly regulated. C) May alter the ability of mRNA to be translated; may alter mRNA stability D) May alter the ability of pre-mRNA to be properly spliced

What are the possible consequences of the following gene mutations outside of the coding sequence? A) Promoter B) Operator C) UTR D) Splice site

The miRNA might incorrectly bind to a mRNA that should have been translated to a protein, causing it to degrade and the cell lacking a necessary protein. -OR- Could cause the miRNA to NOT bind to a mRNA that should not have been translated, causing a protein to be in the cell that should not be there.

What effect might a mutation in a miRNA gene have on the phenotype of a cell?

If the gene is not methylated, it could cause proteins to be transcribed for that cell that shouldn't. This is the type of mutation that causes body parts to grow in inappropriate places.

What effect might a mutation in the DNA methyltransferase gene have on the phenotype of a cell?

1) Missense mutations in Ras gene: changes in the structure of Ras protein that cause it to become permanently activated. 2) Gene Amplification: Abnormal increase in the copy number of a proto-oncogene. 3) Chromosomal Translocation: Certain translocations (like ones that shorten chromosome 22) can fuse the abl gene and bcr gene, yielding an oncogene that encodes an abnormal fusion protein. 4) Viral integration: Certain viruses can integrate their genomes into the chormosomal DNA of their host cell. If the integration occurs next to a proto-oncogene, a viral promoter or enhancer equence may cause the proto-oncogene to be overexpressed.

What four genetic factors can convert proto-oncogenes into oncogenes?

lacZ; cleaves lactose into glucose and galactose. Also, converts lactose into allolactose.

What gene codes for B-galactosidase? What does B-galactosidase do?

lacY; is the membrane protein required for transport of lactose into cell.

What gene codes lactose permease? What does lactose permease do?

lacA; covalently modifies lactose (its functional necessity remains unclear).

What gene codes transacetylase? What does transacetylase do?

Cyclic adenosine monophosphate: a derivative of ATP.

What is cAMP?

Transformation

What is it called when a bacteria assimilates genetic material (DNA) directly from the environment?

Genetic testing is concerned more with individuals and genetic screening is concerned with populations.

What is the difference between genetic testing and genetic screening?

Normal hemoglobin (HbA): Normal alpha and beta genes; normal alpha and beta proteins. Sickle cell hemoglobin (HbS): Normal alpha but mutant beta.

What is the difference between normal hemoglobin and sickle cell hemoglobin?

They are a defense mechanism against viruses in bacteria.

What is the origin of restriction endonucleases?

Binds the Catabolite Activator Protein (CAP) = Increase rate of transcription (positive regulation).

What is the purpose of the CAP site in the lac operon?

Binds mRNA polymerase + sigma factor = basal transcription

What is the purpose of the core promoter in the lac operon?

Binds the lac repressor protein = stop/slow/reduce rate of transcription (negative regulation)

What is the purpose of the operator in the lac operon?

Conditional mutation

What type of mutation affects the phenotype ONLY under a defined set of conditions?

Possible examples: A mutation in the promoter region, histone modification, gene deletion

What type of mutation could result in inhibition of transcription?

Deleterious mutation

What type of mutation decreases chance of survival and reproduction?

Beneficial mutation

What type of mutation enhances the survival or reproductive success of an organism?

Lethal mutation

What type of mutation results in cell death?

Quaternary

What type of structure is hemoglobin?

F+ and F+

What types of bacteria will result from the following conjugation? F+ and F-

Hfr and F-recombinant

What types of bacteria will result from the following conjugation? Hfr and F-

Minutes

What units of genetic distance are used for bacterial conjugation studies?

The mitochondria

Where are oxygen free radicals generated?

A. All of the answers are correct.

Which environmental agent shown can induce mutations? A. All of the answers are correct. B. x-rays C. gamma rays D. UV radiation

Northern Blot

Which of the following methods is used to detect a specific RNA within a mixture of many different RNAs?

Western Blot

Which procedure is used to identify a specific protein within a mixture of many different protein molecules?

Transduction

Which process uses a bacteriophage as an intermediary for the genetic information?

Oxygen free radicals can cause disease; ingesting foods with antioxidants (plants/fruits) and taking vitamin supplements help remove free radicals.

Why should we be concerned about oxygen free radicals, and what can we do to prevent them?

Prototroph

Wild type of bacteria with respect to growth requirements. Able to grow on minimal growth media.

Hardy-Weinberg

states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.