CONNECT QUESTIONS IDK

The most common type of spontaneous mutation in a cell is __________.

• double strand breaks

• depurination

• pyrimidine dimers

• deamination

depurination

UV light and other ionizing radiations damage DNA molecules by __________.

• creating guanine dimers between adjacent guanines in the DNA chain

• creating adenine dimers between adjacent adenines in the DNA chain

• creating thymine dimers between adjacent thymines in the DNA chain

• creating uracil dimers between adjacent uracils in the DNA chain

• creating cytosine dimers between adjacent cytosines in the DNA chain

creating thymine dimers between adjacent thymines in DNA chain

What types of bonds are affected by UV light radiation

Hydrogen bonds in DNA

Chemical agents can cause mutations by inducing ethylation of guanine residues in DNA.

False

Deamination of 5-methyl cytosine results in

Thymine

Tautomeric shifts are when a nucleotide can change

conformation

Tautomeric shifts can result in ———— base pairing.

TG/CA

Oxidative DNA damage can cause 8-oxoG to pair with

Adenine

Which of the following is true about Holliday junctions?

• They only occur in prokaryotes.

• They always result in recombinant chromosomes.

• They always result in non-recombinant chromosomes.

• They can be resolved to result in recombinant or non-recombinant chromosomes.

They can result on both either recombinant or non-recombinant chromosomes

Which step in the Holliday model seems least likely?

• Branch migration

• Nicks at the same site on homologous chromosomes

• Formation of multiple heteroduplex regions

• Resolution of Holliday junctions to form recombinant chromosomes

Nick at the same place in both chromosomes

You are a doctor tasked with diagnosing a patient that comes to you with neurodegenerative symptoms. Upon performing genetic tests, you find he has approximately 50 repeats of CAG in one of his genes. His father and grandfather had similar neurodegenerative symptoms, but were never diagnosed with a condition prior to their deaths. His grandmother, mother, and sisters are unaffected. What disease do you predict that this patient has?

SBMA

The patient has CAG repeats, which narrows the possible diseases down to SBMA, HD, and SCA1. The number of repeats is consistent with all 3 of these diseases. However, only SBMA is inherited in an X-linked manner. This patient, as well as his father and grandfather have similar symptoms, with no affected females, suggesting that this disease is inherited in an X-linked manner, rather than an autosomal dominant manner, which is the case for HD and SCA1.

Ataxia telangiectasia is a neurodegenerative autosomal recessive disease that results in severe disability. It is caused by mutations in the ATM gene. The ATM protein has been shown to play a role in both NHEJ and homologous recombination. What types of DNA lesions do you expect to be present in patients with ataxia telangiectasia?

• Thymine dimers

• Abnormal nucleotides

• Oxidative damage

• Double stranded breaks

double stranded breaks

NHEJ and homologous recombination both repair double-stranded breaks,

An example of a base analog would be __________.

5BU

Which repair mechanism often leads to deletions in chromosomes?

Nonhomologous end joining (NHEJ)

Which of the following most likely accounts for the majority of the recombination events during both DNA repair and meiosis?

• A nick in only one strand of the DNA

• Double-stranded breaks in DNA

• DNA gap repair synthesis

• Heteroduplex formation

Double stranded breaks in DNA

What does the RecA protein does in recombination?

promotes D-loop formation and invasion

what repair process accounts for gene conversion

DNA mismatch repair

You are a doctor tasked with diagnosing a patient that comes to you with mental impairment. Upon performing genetic tests, you find he has approximately 300 repeats of GCC in one of his genes. His father and grandfather had similar mental impairment but were never diagnosed with a condition prior to their death. His grandmother, mother, and sisters are unaffected. What disease do you predict that this patient has?

• SBMA

• HD

• SCA1

• FRAXA

• FRAXE

FRAXE

The patient has GCC repeats and mental impairment, which is consistent with FRAXE. FRAXE is inherited in an X-linked fashion, which is also consistent with the males in his family being affected.

Which diseases arise from the TNRE coding repetitive sequence “CAG“

• HD

• SBMA

• SCA1

What disease is caused by GCC TNRE

FRAXE

Which disease is caused by repetitive CGG TNRE

FRAXA

what disease is caused by repetitive CTG TNRE

DM

Would you predict that Kuru would be able to be treated by gene therapy using the nomral PrP^c gene?

NO

Since Kuru is caused by a prion, which is a misfolded protein with a normal amino acid sequence, you predict that adding a normal gene would not effectively treat the disease.

What are the common types of mutations that occur to convert proto-oncogenes to oncogenes? (Check all that apply.)

• missense

• translocations

• amplifications

Epigenetic changes usually happen to

chromatin modifying proteins (silencing tumor suppressor genes by methylation)

Rb gene is inactive when its phosphorilated this…

promotes cancer

activation of Ras gene…

promotes cancer

duplicate BRCA-1 gene…

prevents cancer

Which genes promote cancer when inactive “tumor-suppressor genes“

• Rb

• BRCA-1

• P53

Translocation mutation are shown in gene sequencing T/F

true

Most cancers rise from environmental factors and carcinogens

true

Chronic myelogenous leukemia is an example of a proto-oncogene activation by __________.

a translocation

Genetic duplications may be caused by

crossing over of misaligned chromosomes

production of gene families, such as the globin genes is the result of ________.

gene duplications

what amount of the population present inversion mutations

2%

Inversion loops happen in

Paracentric and pericentric inversions

Familial Down syndrome is a result of 

Translocation

Which chromosomal change rarely has an effect on the phenotype of the individual who carries it?

Balanced translocation

Robetsonian genetics take place between:

2 non-homologous acrocentric chromosomes

translocation cross happens when person has an

reciprocal translocation

Klinefelter, Jacobs and Turner(XO) syndromes are examples of 

sex chromosome aneuploidy

Trisomy 8 usually leads to early miscarriage of a fetus.  However, adult individuals have been found with cells that have three copies of chromosome 8 in them.  How can this be?

this individual probably has a mosaic region that present trisomy on chromosome 8

What term describes an organism with two complete sets of chromosomes from two different species?

• allotetraploid

• allodiploid

allotetraploid

A _______ translocation represents when a piece of one chromosome is attached to another chromosome.

• simple

• complex

• reciprocal

• balanced

simple

SMAD4 is a tumor suppressor gene located on chromosome 18 that is known to be homozygously deleted in human lung cancer.  If you were to perform comparative genomic hybridization using tissue from a lung cancer patient with a homozygous negative SMAD4 tumor, what ratio of green to red fluorescence would you expect?

A ratio of 1 all across chromosome 18

When an area is deleted on both chromosomes, as in the homozygous deletion of SMAD4, the green to red ratio is 0. But because the deletion only occurs in the area of the SMAD4 gene, the rest of the chromosome will have a ratio of 1; these other chromosomal regions are the same between the lung cancer patient cells and normal cells.

The African clawed frog (Xenopus laevis) is allotetraploid, likely as a result of an interspecies mating long ago, followed by a duplication of the entire genome.  Xenopus laevis is fertile and has a normal life cycle.  In contrast, mules, the allodiploid offspring of a male donkey and a female horse, are generally sterile. Why can Xenopus reproduce and mules cannot?

allotetraploids have all the chromosomes pair up in meiosis whereas in allodiploids this doesnt happen

You perform comparative genomic hybridization. You correctly synthesize your red and green DNA, but you forget to treat the DNA with heat before you apply the samples to metaphase chromosomes.  What will the ratio of green fluorescence to red fluorescence be?

Theres no signal because

When scientists apply colchicine to plants to induce polyploidy, tetraploid plants can form. Is it possible for these tetraploids to be fertile, hence becoming a new species?

Yes, the tetraploids can produce diploid eggs and pollen.

Genetic abnormalities that occur before fertilization may result in some tissues of the body differing in their genetic composition. This is called mosaicism.

False

In individuals with reciprocal translocations, meiosis can produce unbalanced gametes.

true

In polyploids, the chromosomal number is an integral multiple, whereas in aneuploids the number is plus or minus one or more from the diploid number.

true

A phenotypically normal person is having fertility issues. They consult a geneticist. Their karyotype shows they have 45 chromosomes.  Which of the following is the most likely cause of their chromosome abnormality?

Robertsonian translocation

A zedonk is a diploid hybrid animal produced from a cross between a zebra and donkey. A donkey has 62 chromosomes and a zebra has between 32 and 46 chromosomes depending on the species. Zedonks usually have 54 chromosomes. Zedonks are

allodiploid

What are the productsof a recombination event between a normal chromosome and a chromosome with a paracentric inversion?

• 1 normal chromosome

• 1 acrocentric chromosome

• 1 dicentric chromosome

• 1 chromosome with an inversion

In mammals, the majority of cardiomyocytes (cardiac muscle cells) undergo repeated DNA replication without cytokinesis as a part of normal development, and in response to injury or heart attack.  Many cardiomyocytes are tetraploid, and some cells have even higher DNA content.  This variation in DNA content is an example of

• alloploidy.

• aneuploidy.

• copy number variation.

• endopolyploidy.

endopolyploidy

A misaligned cross over between two homologous chromosomes usually results in

a deletion in one chromosome and a duplication in the other one

What mutations alter chromosomal structure

• inversions

• deletions

• translocations

• duplications

1. Copy number variation occurs only as a result of duplications

2. In humans, appropximately 0.4% of the genomes of two unrelated people usually differ with respect to copy number. 

3. Errors in DNA replication are the main way that copy number variation occurs.  

4. Most copy number variation is inherited and happened in the past. 

5. Copy number variation refers strictly to variation in the number of copies of a specific gene in an organism.

6. Scientists generally refer to variations in copy number among members of the same species.  

1. False

2. True

3. False

4. True

5. False

6. True

What is the result of non-disjunction happening in Meiosis I

We will get 2 daughter cells with trisomy and 2 daughter cells with monoploidy

What is the result of non-disjunction happening in meiosis II

We get 1 daughter cell with trisomy, 1 with monoploidy and 2 normal ones.

Homologous genes are the result of random mutations accumulated over the course of many generations.

True

In C. elegans, the hermaphrodite_________ expression off of each X chromosome.

• increases

• decreases

decreases

A person develops Prader-Willi syndrome if they are missing a functional copy of a gene in ch.15 inherited from their

father

A person develops Angelman syndrome if they are missing a functional copy of a gene in ch.15 inherited from their

father

When a cell has a mixture of normal and mutant mitochondria, it is known as_______________

heteroplasmy

Which of the following is a mechanism to imprint genes?

• Methylation of cytosine

• Phosphorylation of adenine

• Methylation of alanine

• Acetylation of cytosine

Methylation of cytosine

The Igf2 locus encodes a growth hormone called insulin-like growth factor 2. Igf2 is an imprinted gene. The copy of the gene inherited from the father is active and the copy inherited from the mother is silenced. Igf2 is the wild type allele. There is also a recessive allele Igf2m. The expression of the Igf2m allele results in dwarf offspring. 

just general data

In four o’clock plants, where are the genes that determine leaf coloration located?

in the chloroplast genome of the egg, maternal inheritance

In snail shell coiling the twisting of the shell is controlled by __________.

a protein produced by nurse cells

You have available a dwarf male mouse with the genotype Igf2m Igf2m and a dwarf female with the genotype Igf2m Igf2. What is the minimum number of generations it would take to produce a normal male? Hint: mice inbreed happily.

2

When you mate the dwarf male mice to the dwarf female mice, the offspring will be half Igf2m Igf2m and half Igf2m Igf2. However, because the mice received their functional copy of Igf2 from their mother, it will be transcriptionally silent, and all animals will be dwarf. If you take an Igf2m Igf2 male and cross it with any of its female siblings, half of the offspring will receive a functional Igf2 gene from their father, and will be normally sized.

Which nucleotide modification occurs in imprinting a gene?

• acetylation

• phosphorilation

• methylation

• nitration

methylation

In which cells do erasure and re-establishment of nucleotide imprinting modifictions typically not occur?

• Nurse cells

• Sperm cells

• Oocytes

• Somatic cells

Somatic cells

What is a disease associated with extra nuclear inheritance?

• Prader-willi

• Angelman syndrome

• LHON

• M. dystrophy

LHON

Which scientists proposed the endosymbiosis theory

Margullis

Wallin

Schimper

The coat color of calico cats is a result of __________.

• Maternal inheritance

• Paternal inheritance

• Extranuclear inheritance

• X inactivation

X-inactivation

Who proposed the X-inactivation theory?

Lyon

Monoallelic expression is associated with what?

genomic imprinting

If the sperm cell contributes mitochondria to the oocyte, it is called __________.

paternal leakage

Codominance

when both alleles are expressed AB blood type example

Which of the following is an example of epigenetic inheritance?

• Expression of the Igf-2 gene based on methylation of the ICR and DMR regions

• Inheritance of flower color as studied by Mendel

• Leaf coloration based on mitochondrial inheritance

• Snail shell twist patterns maternal inheritance

Expression of the Igf-2 gene based on methylation of the ICR and DMR regions

in a dihybrid cross how many genotypes are expected

• 4

• 9

• 16

• 12

9

in a dihybrid cross how many phenotypes are expected

• 4

• 9

• 16

• 12

4

Segregation of the alleles means that a gamete has a ________ chance of getting a particular allele.

• 50%

• 100%

• 0%

• 75%

50%

Which of the following is correct regarding the blending hypothesis of inheritance?

• It suggested that hereditary traits blended from one generation to the next.

• It was possible for the blending to change the trait from one generation to the next.

• It was supported by early research by Joseph Kölreuter.

• It was a prevailing hypothesis of inheritance prior to Mendel.

All of them are correct

Mendel's work with monohybrid crosses provided proof of which of the following?

• blending theory of inheritance.

• particulate theory of inheritance.

• chromosomal theory of inheritance.

• pangenesis.

• none of the answers are correct

Particulate theory of inheritance

Mendel's work with single-factor crosses resulted in the development of which of the following?

• Law of segregation

• Law of independent assortment

• Theory of natural selection

• Law of biological evolution

• All of these choices are correct

Law of segregation

Mendel's work with two-factor (dihybrid) crosses led directly to which of the following?

Multiple Choice

• Chromosomal theory of inheritance

• Particulate theory of inheritance

• Law of segregation

• Law of independent assortment

• Theory of biological evolution

Law of independent assortment

In a dihybrid cross using Mendelian inheritance, if both parents are heterozygous for both traits, what will be the phenotypic ratio of their offspring?

Multiple Choice

• 3:1

• 1:2:1

• 1:1

• 9:3:3:1

9:3:3:1

Which of the following would be used to determine the probability of three independent events in order?

• Sum rule

• Product rule

• Chi-square test

• Binomial expansion

• Random sampling error

product rule

According to Mendel's law of segregation, allele segregation into gametes is __________.

random

The Law of Independent Assortment states that __________.

Multiple Choice

• two different genes will randomly assort their alleles during the formation of haploid cells

• two different alleles will randomly assort during the formation of haploid cells

• two different genes will NOT randomly assort their alleles during the formation of haploid cells

• two different genes will randomly assort their alleles during the formation of diploid cells

Two different genes will randomly assort their alleles in the formation of haploid cells

If the progeny of a mating of pea plants have the following ratios 1342 smooth seed/green pod, 447 wrinkled seed/yellow pod, 429 smooth seed/ yellow pod, 1361 wrinkled seed/green pod what are the genotypes of the parents?

Multiple Choice

• Parent 1: Homozygous for seed shape and pod color

  Parent 2: Heterozygous for seed shape and homozygous for pod color

• Both parents are heterozygous for seed shape and pod color

• Parent 1: Heterozygous for seed shape and pod color

  Parent 2: Homozygous seed shape and heterozygous for pod color

• Parent 1: Heterozygous for both seed shape and pod color

  Parent 2: Homozygous for both seed shape and pod color

• Parent 1: Heterozygous for seed shape and pod color

  Parent 2: Homozygous seed shape and heterozygous for pod color

This is a two-gene cross involving the genes for seed shape (S) and pod color (G). We can tell right away that both plants are not heterozygous for both genes, because then we would observe a 9:3:3:1 ratio. We can also tell that one of the parents for seed shape is going to be homozygous recessive and one is going to be heterozygous, because there are as many progeny with smooth seeds as there are with wrinkled seeds. If we write out the ratios for the different answers, we can see that the following answer is the only one that gives the desired ratios:

Parent 1: Heterozygous for seed shape and pod color

Parent 2: Homozygous seed shape and heterozygous for pod color

In this cross you are crossing a SsGg parent with an ssGg parent. The progeny you expect are:

3 SsG_ Smooth green

1 Ssgg Smooth yellow

3 ssG_ Wrinkled green

1 ssgg Wrinkled yellow

These ratios fit with the numbers in the question.

Transcription of the lac operon results in the production of how many different mRNA transcripts?

Multiple Choice

• 1

• 2

• 3

• 4

1

Does lactose inhibit or activate Lac operon transcription

lactose activates transcription

How is the lac operon regulated?

• It is repressible, under negative and positive control.

• It is repressible, under negative control.

• It is inducible, under positive control.

• It is inducible, under negative and positive control

It is inducible by positive and negative control because lactose activates transcription by binding to repressor so its induced.

Which gene is responsible for producing the protein that converts lactose to allolactose?

• lacZ

• lacI

• lacY

• lacA

Lac Z

LacI codes for repressor

Lac Y codes for transport of lactose to cytoplasm

LacA prevents lactose build-up

The structural proteins encoded by the lac operon are involved in lactose synthesis T or F

False

The CAP protein is an activator that binds to the operator.
true or false

False CAP proteins bind to the CAP site in promoter

Does glucose inhibit or increase lac operon transcription

it inhibits

How many binding sites are there in the lac operon for the lac repressor?

• 2

• 4

• 3

• 5

answer is 3