genetics final

Patau Syndrome is an autosomal disorder caused by an additional chromosome. If a male child is affected with Patau Syndrome, how many Barr bodies are found in his nuclei.

0

A man heterozygous for blood type B marries a woman of blood type AB. The chance that their first child will have type O blood is -------

0%

How many origins of replication are there on a bacterial chromosome?

1

What stem-loop conformations favor attenuation?

1-2 and 3-4

Which of the following is not an example of euploidy?

Aneuploid

Variation in a particular chromosome is called ----------while variation in the number of complete sets of chromosomes is called ---------------

Aneuploidy, Euploidy

Genes transferred from father to son only is called

B) holandric genes C)Y -linked genes

In tomatoes, yellow flowers (Y) are dominant to white flowers (y) and round fruit (R) is dominant to oblong fruit (r). You cross a heterozygous yellow round plant with a plant with white flowers and oblong fruit. You get the following progeny: 238 yellow round210 yellow oblong270 white round282 white oblongFormulate a null hypothesis and performing a chi square analysis on it, what chi square number would you obtain? Based upon this number, would you reject or accept your null hypothesis? Use the table listed below.

Chi square = 12.7; reject

Find the constitutive and alternative exons between Protein 1, 2 and 3

Constitutive: 1, 5 and 6; Alternative: 2, 3 and 4

Met B null mutants in Fig. above need to be supplemented with which molecule for methionine biosynthesis?

Cystathionine

The enzyme which do the primer removing function of Flap Endonuclease in prokaryote is

DNA Polymerase I

Okazaki fragments are

DNA fragments polymerized by DNA pol III

What is the chromosomal system for sex determination in birds?

Z-W

Alternate versions of a specific gene are called ________.

alleles

In the lac operon, the CAP site is located next to the __________. When both lactose and glucose are present, this leads to a rate of transcription that is __________.

promoter; low

What is the name of the enzyme that adds CCA to the 3' end of tRNAs?

tRNA nucleotidyltransferase

A dihybrid plant was crossed; the F2 generation consisted of: 219 tall plants with purple flowers; 79 dwarf, purple plants; 65 tall, pink plants; and 21 dwarf, pink plants. The data remind you of a 9:3:3: 1 ratio. What is the chi-square value in the test of this hypothesis?

1.8

A tetrahybrid heterozygous plant, exhibiting independent assortment at all four loci, is self-fertilized What is the probability that an offspring will have the recessive phenotype at all four loci?

1/256

A male Manx cat and a female Manx cat produce kitten. What is the probability that kitten has a non-manx tail?

1/3

How many bases are necessary to complete ten complete turns of a DNA helix?

100

A protein called actin consists of 376 amino acids. The mRNA for actin must be longer than

1128

An F1 cross between Xyw+/ Xy+w female fly with that of Xy+w/Y male fly resulted in below F2 progeny. Xyw+/Y 448 Xy+w/Y 441 Xy+w+/Y 76 Xyw/Y 53 Total 1018 Find the distance between y and w genes in map units

12.7

The table below is a data from triple heterozygote cross with a homozygous recessive parent. Genotype Observed ABC 390 abc 374 AbC 27 aBc 30 ABc 5 abC 8 Abc 81 aBC 85 Total 1000 Find the distance between first gene and the middle gene

17.9 cM

The table below is a data from triple heterozygote cross with a homozygous recessive parent. Genotype Observed ABC 390 abc 374 AbC 27 aBc 30 ABc 5 abC 8 Abc 81 aBC 85 Total 1000 From the data given in find the gene order

ACB

The pairwise map distances for four linked genes are as follows: A-B = 22 m.u., B-C = 7 m.u., C-D = 9 m.u., B-D = 2 m.u., A-D = 20 m.u., A-C = 29 m.u. What is the order of these four genes?

ADBC

The most commonly observed modification in the histone includes ___________

Acetylation of lysine and phosphorylation of serine

Cells are treated with a drug that blocks purine synthesis. Which bases would not be made in those treated cells?

Adenine and guanine Explanation The double-ring purine bases are adenine (A) and guanine (G), where the single-ring pyrimidine bases are thymine (T), cytosine (C), and uracil (U).

During transformation, if the extracellular endonuclease was not functioning properly, at which stage would transformation be halted?

After DNA fragment binding to a cell surface receptor on the bacterium Explanation Endonuclease cleavage occurs after a DNA fragment binds to a cell surface receptor on a competent bacterium. Therefore, if the endonuclease was not functioning properly, transformation would be blocked after that step.

A woman who is heterozygous for an allele that results in X-linked pattern baldness marries a man who is nonbald. Which of the following would be true of their offspring?

All of the females would be nonbald, ½ of the males would be bald Explanation Pattern baldness often follows an X-linked recessive pattern of inheritance. The man will pass on an unaffected allele on his X chromosome to all his daughters, who will be nonbald. As a heterozygous carrier, woman will pass on the affected allele on her X chromosome to half of her sons, who will be bald.

Dideoxy nucleotides are used in which technique?

DNA sequencing

In the Meselson and Stahl experiment shown in Fig, after two rounds of replication in light media, the DNA distributed itself in the tube as one light and one medium band

Dz

Choose from below RNA with catalytic activity

Group I intron Group II intron Peptidyl transferase

You are performing a ChIP-Seq experiment, and you would like to sequence all DNA fragments wrapped around histone octamer. You need to choose the antibody to obtain all nucleosomes. Which antibody do you think is ideal for your experiment?

H4

Which of the following matings would have the highest frequency of chromosomal gene transfer?

Hfr x F-

The two DNA strands are held together as a double helix by

Hydrogen bond

The CRISPR-Cas system in bacteria is most similar to what system in vertebrates?

Immune system

With which injection did Mello and Fire observe the lowest amount of mex-3 probe staining?

Injected with double-stranded RNA

Given the following sequence of genes on a chromosome, determine what change in chromosome structure occurred. (The * indicates the centromere.)before A B C D * E F G Hafter A C D * E F G H

Interstitial deletion

Acetylation of histone increases transcription of gene due to ___________

It loosens the DNA-histone complex thus making it accessible to RNA polymerase

Which of the following is correct concerning F factors?

It may integrate into the host chromosome. It stands for fertility factor. It allows conjugation to occur. F+ bacteria act as donor strains in conjugation.

Which human cells exhibit endopolyploidy?

Liver cells

Which of the below is not considered to be a cis element?

Mediator

Determine the amino acid sequence of the below sequence. Also determine the amino acid sequence when a "G" nucleotide is inserted between the 4th and 5th nucleotide. 5' AUGGUUCCAAGGUUC 3'

Met-Val-Pro-Arg-Phe; Met-Gly-Ser-Lys-Val

Identify the stage of cell division

Mitosis -Metaphase

Infer the cellular lactose and glucose level from the above Fig.

No lactose or Glucose

What is the type of mutation in Strain 2? strain 1 5' GCU GGA GCA CCA GGA CAA GAU GGA 3' Strain 2 5' GCU GGA GCA CCA GGA (U)AA GAU GGA 3'

Nonsense mutation

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 strand5' - G A T C T C C C A A T T - 3' mutated strand

Transversion Explanation This mutation changes a guanine to a cytosine. Because this is a change from a purine to a pyrimidine, it is a transversion.

Individual with Type AB blood is -----------and Individual with Type O blood is ------------

Universal recipient; Universal donor

You are performing a fruit fly cross similar to those that Morgan performed. Unfortunately, you forgot to write down the parents of your cross. You count the progeny, and find you have 80 red-eyed males, 160 red-eyed females, and 80 white-eyed males. Assuming that all genotypes from this cross should have equal survival rates, what are the genotypes of the parent flies?

Xw+Y and Xw+Xw

An example of a mutagen that integrates into the double-helix of DNA resulting in the inhibition of DNA replication would be __________.

acridine dyes

Nondisjunction is related to a number of serious human disorders. How does nondisjunction cause these disorders?

alters the chromosome number

What is the order of the genes in this experiment? Genes % Cotransduction a-b 45 a-c 10 b-c 6

bac

When wild-type offspring are produced from a cross between parents that both display the same recessive phenotype (ie. there are two genes causing the trait), this illustrates the genetic phenomenon of _______.

complementation

The end result of meiosis in animals is ______.

four haploid cells

In overdominance, the _______ genotype is beneficial over the _______ genotypes.

heterozygous, homozygous

A white cat whose parents are both white produces only black offspring when mated with a black cat. The white cat is most probably --------------.

homozygous recessive

A testcross is always performed between the individual that is heterozygous for the genes to be mapped and an individual who is ____________.

homozygous recessive for the genes

In meiotic nondisjunction, meiotic products can be n+1, n-1, or n depending on when nondisjunction occurs. If non disjunction occurs in Meiosis I, what is the outcome?

two trisomic and two monosomic products

An individual with type A blood and an individual with type B blood mate and have offspring. What blood type is not possible in their offspring?

type O, AB, B,A

Kinetochore microtubules are attached to bivalents in

xf Meiosis I Prometaphase

In four-o'clock plants, red flower color is dominant to white flower color. However, heterozygous plants have a pink color. If a pink-flowered plant is crossed with a white-flowered plant, what will be the phenotypic ratios of their offspring?

½ pink, ½ white Explanation: Flower color demonstrates a pattern of incomplete dominance in the four-o' clock plant. The genotypes of the plants in this cross are CRCW (pink) × CWCW (white).

You have discovered a strain of E. coli that has a higher mutation rate than the normal parental strain from which the mutated strain was created. Upon further investigation, you find a mutation in the DNA polymerase III gene. What subunit of the holoenzyme does this mutation probably NOT affect?

β Explanation Since the beta subunit is the clamping subunit and the rest are invovled in addining nucleotides or proofreading beta would be the best selection.

Genes a and b are 20 map units apart, b and c are 30 map units apart, and a and c are 50 map units apart. If a triple heterozygote is testcrossed, among 1,000 progeny, how many are expected to result from double crossovers if the interference is 70%

18

If the origin of transfer was located directly to the right of the galE gene on this map of the E. coli chromosome, and gene transfer proceeded counterclockwise, how many minutes after the galE gene was transferred would the dnaB gene be transferred in an interrupted mating experiment?

25 minutes Explanation The galE gene is located at approximately 16 minutes. If the origin of transfer was located directly to the right of the galE gene, galE would be transferred very soon after the start of the experiment, followed by lacA,Y, Z, then proA, B, etc. thrA would be transferred at around 16 minutes. On this map, dnaB is located at around 91 minutes, so the distance from thrA to dnaB is 9 minutes. By adding together 16 minutes and 9 minutes, we can determine that dnaB would be transferred 25 minutes after galE if transfer proceeded counterclockwise.

If individual II-4 marries a person with the same genotype as individual II-2, what is the chance that one of their children will be afflicted with hemophilia?

25%

Consider the following mRNA from a eukaryotic species. Which AUG codon is translation most likely to begin from? 5'-CCUAUGAGCCACCAUGGAUGCCAAAUGCA-3'

2nd Explanation The consensus sequence for optimal start codon recognition in complex eukaryotes is: GCC(A/G)CCAUGG, positioned from -6 to +4. Aside from an AUG codon itself, a guanine at the +4 position and a purine, preferably an adenine, at the −3 position are the most important sites for start codon selection.

After screening a colony of bacteria for mutations in a given gene, you discover 100 mutant colonies out of 3 million total colonies. What is the mutation frequency for this gene in the population?

3.3 x 10^-5 Mutation frequency is calculated by dividing the number of mutant genes by the number of copies of that gene in the population. Here, we divide 100 by 3 million to get 3.3 x 10-5.

In the Hershey-Chase experiments, the DNA of the bacteriophage was labeled with the

32P radioisotope

A bivalent contains how many chromatids?

4

Consider the following origin of replication that is found on a chromosome in Fig.. The sequence of region 1 is shown below What would be the sequence of the newly synthesized lagging daughter strand?

5' ....TGTCAGTCAG...3'

Consider the following DNA sequence, which codes the first portion of a long protein beginning at the ATG (AUG in mRNA) start codon. 5' ATG CCC CGC AGT AGG GGG TGG AGA 3' Which of the mutated sequences listed is most likely to be a deleterious mutation?

5' ATG CCC CGC AGT AGG GGG TGA AGA3' Explanation The sequence 5' ATG CCC CGC AGT AGG GAG TGG AGA 3' includes a missense mutation, changing a glycine to a glutamic acid. The sequence 5' ATG CCC CGC AGT AGG GGG TGA AGA 3' includes a nonsense mutation, introducing a premature stop codon in the 7th codon. The sequence 5' ATG CCG CGC AGT AGG GGG TGG AGA 3' includes a silent mutation in the second codon which does not alter the amino acid. The nonsense mutation, which introduces a premature stop codon in the 7th codon, is most likely to be deleterious for the cell, because the truncated protein is unlikely to be able to carry out its normal function.

Which DNA sequence would also work in place of the following bi-directional enhancer?5' GTTC 3' 3' CAAG 5'

5' GAAC 3' 3' CTTG 5' Explanation A property of enhancers is that they can work in either direction.

Find the sequence of the "Sense" strand. 5' TTCCAAGGTTCCAAGG3' 3' AAGGTTCCAAGGTTCC 5' Transcription 5' UUCCAAGGUUCCAAGG 3'

5' TTCCAAGGTTCCAAGG 3'

The two processes of wrapping DNA on nucleosomes and arranging them into a 30-nm fiber shorten the DNA by how much?

50 fold

You are studying a diploid organism that has 14 pairs of chromosomes. How many chromatids would this cell have in G2 phase?

56 Explanation Once chromosome replication during S phase is completed, a cell has twice as many chromatids as it had chromosomes in the G1 phase. In this example, a somatic cell from this organism in G1 phase has 28 distinct chromosomes, whereas it has 28 pairs of sister chromatids, for a total of 56 chromatids, in G2.

Cystic fibrosis is an autosomal recessive disorder that affects lung function in humans. A man and a woman are both unaffected heterozygous carriers of a cystic fibrosis gene. If the couple has two children, what is the probability that their first child will be unaffected and their second child will be unaffected?

56.25% Explanation There are three possible scenarios that would satisfy the requirements of this question: 1) girl, girl, boy, 2) girl, boy, girl or 3) boy, girl, girl. The likelihood of each individual possibility is 1/2*1/2*1/2 or 1/8. Therefore using the addition rule, the likelihood that any of these three possibilities will occur is 3/8.

Genes a and b are 20 map units apart, b and c are 30 map units apart, and a and c are 50 map units apart. If a triple heterozygote is testcrossed, among 1,000 progeny, how many are expected to result from double crossovers if there is no interference?

60

How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEEFF?

8

In the beads on a string model, the bead is made up of __________

8 histone proteins

Suppose the P and k genes are on the same chromosome and separated by 20 map units. What fraction of the progeny from the cross Pk/pK X pk/pk would be parental type?

80

A diploid organism has a total of 48 chromosomes. Assuming all possible chromosome combinations are viable, if a mutant tetraploid version of this organism was created how many chromosomes would it have? If a mutant version of this diploid organism was monosomic for chromosome 9 how many chromosomes would it have?

96; 47

The branch point site conserved sequence for spliceosome is ___________

A

Eosin, white, and red (wild type) are all alleles of the same gene white (w), located on the X chromosome, where red is dominant to white. Eosin is a pale orange color. The expression of the eosin allele depends on the number of copies present. Females homozygous for the eosin allel have eosin eyes. Females heterozygous for the eosin and white alleles have light-eosin eyes. Females heterozygous for the red and eosin alleles have red eyes. Males that have a single copy of the eosin allele have eosin eyes. If an eosin-eyed male Drosophila is crossed to a homozygous red-eyed female, what will be the phenotype of their offspring?

All offspring will have red eyes. Explanation The female parent carries only the wild-type allele (Xw+), which she will pass on to both her male and female offspring, who will in turn also have red eyes since red is dominant to both the eosin and white alleles.

Which of the following represents the lowest level of chromosome condensation?

Nucleosome

Which of the following is not a component of the nucleic acid backbone?

Nucleotide

What site does the initiator tRNA bind to on the ribosome?

P

The process of crossing over occurs during which phase of meiosis?

Pachytene

Find the amino acid that is charged to the tRNA in Fig. from the codon table.

Pro

If a nucleotide in a eukaryotic mRNA coding sequence does not appear in the genomic DNA sequence, the most likely modification to have occurred is __________.

RNA editing

How does DNA differ from RNA?

RNA uses a different five-carbon sugar.

Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot appropriately metabolize a particular amino acid. This amino acid is not otherwise produced by humans. Therefore, the most efficient and effective treatment is which of the following?

Regulate the diet of the affected persons to severely limit the uptake of the amino acid.

DNA topoisomerase I does which of the following?

Relaxes negative supercoils

A gene is inducible and under negative control. Which of the following pairs will allow expression of this gene?

Repressor + inducer Explanation Negative control refers to transcriptional regulation by a repressor. An inducer is a small effector molecule that causes the rate of transcription to increase. One way that it does this is to bind a repressor and prevent it from binding the DNA. Therefore, an inducible gene that is under negative control will be transcribed when a repressor and an inducer is present.

Primer used for the process of polymerase chain reaction are ______________

Single stranded DNA oligonucleotide

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?

The genetic distance between genes A and M is 11 minutes. The genetic distance between genes A and T is 19 minutes. The genetic distance between genes M and T is 8 minutes. The order of the genes is A M T. All of these choices are correct. Explanation In a conjugation mapping experiment, the distance between two genes is calculated by comparing their times of entry into the recipient strain. So, for example, to calculate the distance between A and M we subtract the entry time of A (26 minutes) from the entry time of M (37 minutes). The order of the genes is deduced based on the order of entry into the recipient strain.

What is unusual about the 5' cap found on almost all eukaryotic mRNAs?

The nucleotide added is a guanine methylated at N7 and the bond is created between the phosphate group on the guanine and the phosphate on the terminal nucleotide

If the Trp codons in the trpL gene were mutated to encode another amino acid, what would the result be?

The trp operon would never be transcribed. Explanation If there were not Trp codons in the trpL mRNA, the ribosome would never pause within region 1 of the mRNA. Translation of the trpL mRNA would progress to its stop codon, where the ribosome would pause. This pausing prevents region 2 from forming a stem loop. Region 3 hydrogen bonds with region 4, which terminates transcription of the rest of the trp operon.

Heavy metals, such as copper, are required for proper development. However, if too much copper is present it can lead to developmental defects. A scientist was interested in studying the developmental defects that could occur at various concentrations of copper. Genetically identical organisms were grown in 6 different concentrations of copper. This experiment evaluates a/an _____________.

norm of reaction Explanation Norm of reaction refers to the effects of environmental variation on a phenotype. Specifically, it is the phenotypic range seen in individuals with a particular genotype. To evaluate the norm of reaction, researchers begin with true-breeding strains that have the same genotypes and subject them to different environmental conditions.

The proofreading of newly synthesized DNA by DNA Pol III occurs in __________.

the 3' to 5' direction

The peptidyl transferase is a component of __________.

the ribosome