Gen Final
Jack and Jill's son Jake has a severe case of myclonic epilepsy and ragged-red fiber (MERRF) syndrome. His case includes frequent and disabling myclonic seizures (involuntary twitching of the muscles) along with hearing loss, exercise intolerance, and poor night vision. Like most cases of MERRF, his case is associated with a mitochondrial mutation that he inherited from his mother Jill. His mother doesn't know that she harbors the MERRF mutation among her mtDNA molecules, but she has experienced occasional mild muscle twitching throughout her life and she does not see very well at night. What is/are the MOST likely explanation(s) for the difference in the severity of MERRF between Jake and his mother? (Select all that apply.) - Heteroplasmy for mtDNA molecules in the cells of his mother is responsible. - Some random mutations took place in Jack's mitochondria, which caused MERFF syndrome as his mother does not have full symptoms. -The expression pattern of the mutant gene may be different in males than in females. -It is likely that Jake has a higher proportion of mutant mtDNA molecules in his cells compared to his mother.
- Heteroplasmy for mtDNA molecules in the cells of his mother is responsible. -It is likely that Jake has a higher proportion of mutant mtDNA molecules in his cells compared to his mother.
There are some genomes that have been reported to be positively coiled instead of negatively supercoiled, which is the status of most genomes that we have studied. The genomes that are positively supercoiled seem to belong to viruses and cells that exist at very high temperatures. Why might positive supercoiling be an advantage at high temperatures? (Select all that apply.) - Positive supercoiling would allow the DNA to maintain its double-stranded structure at higher temperature. - Positive supercoiling would allow the DNA to readily separate for transcription and replication. - The high temperature would increase the formation of the hydrogen bonds between bases. - At high temperatures, the condition is more conducive for the strands to denature. - Negative supercoiling makes it more difficult for strands to separate while positive supercoiling would allow the strands to separate more readily.
- Positive supercoiling would allow the DNA to maintain its double-stranded structure at higher temperature. - At high temperatures, the condition is more conducive for the strands to denature.
Indicate which of the following statements is TRUE. Select all that apply. - Ribose sugars have a hydroxyl on the 2' carbon. - A-, B-, and Z-form DNA are all right-handed helixes. - All organisms contain DNA that is roughly 25% A, 25% T, 25% G, and 25% C. - There are three phosphates between each sugar in a molecule of DNA. - There are two hydrogen bonds between AT pairs.
- Ribose sugars have a hydroxyl on the 2' carbon. - There are two hydrogen bonds between AT pairs.
A man has a condition where all of his gametes undergo meiosis I normally, but there is nondisjunction of the sex chromosomes in meiosis II. He mates with a woman who produces all normal gametes. What is the probability that the fertilized egg will develop into a child with Klinefelter syndrome (XXY)? Assume that all gametes and zygotes are viable. 1/8 1/4 1/3 0 1/2
0
How many Barr bodies would an individual with a XYY genotype possess?
0
In cocker spaniels, solid coat color is dominant over spotted coat color. If two heterozygous dogs were crossed to each other, what would be the probability of having a first litter of 8 pups, the firstborn with spotted fur, and then among the next 7, 2 with spotted fur and the rest with solid fur; and then a second litter of 6 pups, 4 with spotted fur and the rest with solid fur. Please give the single final probability in decimal form with three significant figures.
0.00256
Imagine that two unlinked autosomal genes with simple dominance code in goats for size, where L is large and l is small, and for color, where B is brown and b is white. If a small, white male goat mates with a large, brown female goat of an unknown genotype, what is the probability that they would produce small, white offspring? Please give your answer as a decimal with three significant figures
0.0625
What is the probability of obtaining an AABB zygote from the cross AaBb x AaBb? Please express your answer as a decimal with three significant figures.
0.0625
What is the probability of obtaining an AbC gamete from an AaBbCc individual? Please express your answer as a decimal with 3 significant figures.
0.125
What is the probability of obtaining an aB phenotype from the cross AaBb x AaBB? Please express your answer as a decimal with three significant figures.
0.250
Polydactyly is expressed when an individual has extra fingers and/or toes. Assume that a man with six fingers on each hand and six toes on each foot marries a woman with a normal number of digits. Having extra digits is caused by a dominant allele. The couple has a son with normal hands and feet, but the couple's second child has extra digits. What is the probability that their third child will have polydactyly?Please give your answer as a decimal
0.5
Two parents with blood types A and AB have a child who has B blood type. What is the chance that their next child will be type A (don?t consider the Bombay Phenotype)?Please give your answer as a decimal
0.50
Given a chi-squared value of 3.455 and 6 degrees of freedom, what would be the p-value?
0.75
Given the following observed and expected data (total of 1000), using chi-squared calculate a p-value that corresponds with this data: Phenotype Observed Expected cinnabar, vestigial 384 390 roof 408 390 cinnabar, roof, vestigial 63 70 wild type 72 70 vestigial 32 35 cinnabar, roof 34 35 roof, vestigial 4 5 cinnabar 3 5 0.05>p 0.9>p>0.75 0.25>p>0.1 0.75>p>0.5 0.95>p>0.9
0.9>p>0.75
What is the correct order of events: 1. Chromosome condenses 2. Homologous chromosome separate 3. Crossing over 4. Lining up on metaphase plate 5. Pairing up to form tetrad
1 5 3 4 2
A man has a condition where all of his gametes undergo nondisjunction of the sex chromosomes in meiosis I, but meiosis II proceeds normally. He mates with a woman who produces all normal gametes. What is the probability that the fertilized egg will develop into a child with Turner syndrome (XO)? Assume that all gametes and zygotes are viable. 1/2 0 1/8 1/4 1/3
1/2
Common red-green color blindness is an X-linked recessive trait. A normal woman whose father is colorblind married a normal man and they have one son. What is the probability that he is colorblind?
1/2
In the cross Aa Bb Cc Dd � Aa Bb Cc Dd, in which all genes undergo independent assortment, what proportion of offspring are expected to be homozygous recessive for all four genes? 1/16 1/256 1/20 1/4
1/256
In Labrador retrievers, the allele for black coat color (B) is dominant to the allele for brown coat color (b). However, if a lab has two copies of the recessive allele for a pigment-depositing gene (e), it can only have yellow coat color. In a cross of two doubly heterozygous black labs (BbEe x BbEe), what fraction of the next generation would one expect to be yellow?
1/4 ???????
Mendel crossed peas with round, green seeds with peas having wrinkled, yellow seeds. 100% of the F1 plants had seeds that were round and yellow. Predict the results of test-crossing these F1 plants. 9/16 round, yellow; 3/16 round, green; 3/16 wrinkled, yellow; 1/16 wrinkled, green 1/4 round, yellow; 1/4 round, green; 1/4 wrinkled, yellow; 1/4 wrinkled, green 3/4 round, yellow; 1/4 wrinkled, green 1/2 round, yellow; 1/2 wrinkled, green None of the Above
1/4 round, yellow; 1/4 round, green; 1/4 wrinkled, yellow; 1/4 wrinkled, green
Heat can disrupt hydrogen bonding between DNA strands, causing denaturation. Which of the following DNA strands would have the HIGHEST denaturation temperature considering the different number of base pairs between the various bases? 90% AT and 10% GC 70% AT and 30% GC 30% AT and 70% GC 10% AT and 90% GC 50% AT and 50% GC
10% AT and 90% GC
In fruit flies, curved wings are recessive to straight wings, and ebony body is recessive to gray body. A cross was made between flies (all true-breeding) with curved wings and gray bodies to flies with straight wings and ebony bodies. The F1 offspring were then testcrossed to produce an F2 generation. The following data were obtained: F2 generation: -104 curved wings, ebony body -106 curved wings, gray body -98 straight wings, gray body -92 straight wings, ebony body With a null hypothesis based on independent assortment, what are the expected values for each class of flies (400 total flies)? curved wings, ebony body: ______________ curved wings, gray body: _________________ straight wings, gray body: ________________ straight wings, ebony body: ________________
100 100 100 100
Crossing two yellow mice results in 2/3 yellow offspring and 1/3 nonyellow offspring. What percentage of offspring would you expect to be nonyellow if you crossed two nonyellow mice?
100%
Given the observed data shown here, what is the distance between the roof and vestigial genes? Phenotype Observed Expected cinnabar, vestigial 384 390 roof 408 390 cinnabar, roof, vestigial 63 70 wild type 72 70 vestigial 32 35 cinnabar, roof 34 35 roof, vestigial 4 5 cinnabar 3 5 6.6map units 7.3 map units 13.5 map units 14.2 map units None of the Above
14.2 map units
In fruit flies, vestigial wings are recessive to normal wings, and ebony body is recessive to normal body. A cross was made between flies (all true-breeding) with normal wings and normal bodies to flies with vestigial wings and ebony bodies. The F1 offspring were then self-crossed to produce an F2 generation. The following data were obtained (observed): F2 generation: Type Predicted Obtained -Normal wings, normal body 9 452 -Normal wings, ebony body 3 126 -Vestigial wings, normal body 3 101 -Vestigial wings, ebony body 1 41 Total = 720 -What is the chi-squared value for this set of data? Please use decimals as necessary for your answer (3 sig figures). chi-squared= _________________
14.9
How many complete rotations would most likely correspond to a positively supercoiled DNA molecule that is 100 bp in length? 10 0 15 5
15
While mapping two genes in Drosophila, you observe 30 recombinants among 200 total offspring. What is the distance between these genes? Please answer with a numeral (1, 2, 3 etc.) _____________map units
15 map units
Manx cats are heterozygous for a dominant mutation that results in no tails (or very short tails), large hind legs, and a distinctive gait. Homozygous dominant individuals are not viable (they die before birth). A male Manx cat and a female Manx cat produce a live kitten. What is the probability that the kitten has a manx tail?
2/3
The house fly, Musca domestica, has a haploid chromosome number of 6. How many chromatids should be present in a diploid, metaphase cell (metaphase of mitosis)? 18 24 6 3 12
24
How many DNA strands are found in the following cell? (6 chromosomes total, each made of two sis chromatids. That means there are 12 chromatids total)
24 Each chromatid = 2 complimentary strands of DNA.
A geneticist is using a three-point testcross to map three linked Drosophila recessive mutations called a, b, and c, where a is associated with anomalous gait, b is associated with buckled wings, and c is associated with curved bristles. She first crosses homozygous anomalous, buckled flies to homozygous curved flies. Next, she test crosses the F1 progeny to anomalous, buckled, curved flies. She obtains 1000 progeny distributed as shown. Testcross progeny phenotype Number Curved 277 anomalous, buckled 283 Wild Type 4 anomalous, buckled, curved 6 buckled, curved 128 anomalous 132 anomalous, curved 83 buckled 87 From this data, calculate the map distance between b and c. Please give your answer as a whole number.
27 map units
The sex of birds, some insects, and other organisms is determined by a ZW chromosomal arrangement in which the males have like sex chromosomes (ZZ) and females are ZW (similar to XY in humans). Assume that a recessive lethal allele on the Z chromosome causes death of an embryo in birds. What sex ratio would result in the offspring if a cross were made between a male heterozygous for the lethal allele and a normal female? 3:1 male to female 1:2 male to female 1:3 male to female 2:1 male to female 1:1 male to female
2:1 male to female
Assuming independent assortment, how many different gametes can be formed by an organism that is homozygous for three and heterozygous for three genes? 4 3^2 2^3 2 6
2^3
In fruit flies, curved wings are recessive to straight wings, and ebony body is recessive to gray body. A cross was made between flies (all true-breeding) with curved wings and gray bodies to flies with straight wings and ebony bodies. The F1 offspring were then test-crossed to produce an F2 generation. The following data were obtained: F2 generation: -104 curved wings, ebony body -106 curved wings, gray body -98 straight wings, gray body -92 straight wings, ebony body How many degrees of freedom are there in this problem?
3
While mapping two genes in Drosophila, you observe 160 recombinants among 490 total offspring. What is the distance between these genes? Please round to one decimal point ________map units
32.7 map units
If 15% of the nitrogenous bases in a sample of DNA from a particular organism is thymine, what percentage should be cytosine? 15% 40% 70% 30% 35%
35%
Assuming there are no heteroplasmic individuals but that people from different families have different DNA, how many different mitochondrial DNAs are there in this entire pedigree? [] = male, () = female I [1]--------(2)------[3] ______|______ ______|______ II (1)----[2] (3) (4) (5) [6] (7) __|__ III (1)
4
In fruit flies, the recessive pr and cn mutations cause brown and bright-red eyes, respectively (wild-type flies have brick-red eyes). The double mutant pr-cn combination has orange eyes. An F1 female who is wild-type is crossed to an orange-eyed male. Their F2 progeny have the following distributions: Phenotype Observed wild type 8 brown 241 bright-red 239 orange 12 Total 500 What is the map distance between the pr and cn genes? 0.04 map units 8 map units 4 map units 20 map units 0.02 map units
4 map units
Please match each of the following scientists or groups of scientists with their discoveries. Not all answer options will be used. -Rosalind Franklin -Erwin Chargaff -Fred Griffith -Alfred Hershey and Martha Chase -Avery, MacLeod, and McCarty -Watson and Crick 1)used models to show the full double helical structure of DNA 2)found that ?the transforming principle? is destroyed by enzymes that hydrolyze DNA 3)used radioactivity to label heavy and light forms of DNA in bacteria that were then separated by density centrifugation 4)used X-ray diffraction to show that the structure of DNA is helical 5)found that the phosphorus-containing components (DNA) are the genetic material of phages 6)discovered ?the transforming principle? that could genetically alter bacteria 7)studied proteins and determined that they naturally form alpha helical structures 8)Although the ratio of A/T and G/C is the constant, the relative amount of any particular base varies between species.
4-Rosalind Franklin 8-Erwin Chargaff 6-Fred Griffith 5-Alfred Hershey and Martha Chase 2-Avery, MacLeod, and McCarty 1-Watson and Crick
Match the labels below to the numbered label lines on this interior portion of a DNA molecule. (Labels in the pic go from 1-8) -hydrogen bond -pyrimidine -phosphodiester bond -phosphate -5' end -sugar -3' End -purine
4. hydrogen bond 3. pyrimidine 5. phosphodiester bond 2. phosphate 1. 5' end 6. sugar 7. 3' End 8. purine
How many TYPES of histone proteins are there? 5 8 9 7 4
5
How many base pairs per turn of the helix would most likely correspond to a positively supercoiled DNA molecule? 5 10 100 0 15
5
Data shows that X-linked recessive trait of color-blindness is present in 5% of males overall in the population. However, if a mother who is a carrier and father who is unaffected plan to have 2 children, what is the probability the children will be both normal females?
50%
How many chromosomes are found in the following cell? (3 chromatids being pulled to either side of the cell. They are single chromatids, not sisters. There are 6 chromatids total: 3 on left, 3 on right)
6 Each chromatid if alone = one chromosome Sets of sister chromatids, when stuck together = one chromosome.
How many DNA molecules are found in the following cell? 6 chromatids total, 6 chromosomes total. 3 chromatids each being pulled to either side of the cell.
6. ALSO REMEMBER: One DNA molecule = one chromatid.
The Drosophila genes for white eyes (w), cut wings (ct), and tan body (t) lie at map positions 2.0, 16.0, and 35.0, respectively. Of 1000 progeny, 7 are double crossovers. What is the degree of interference?
73.7%
Identical twins are produced from the same sperm and egg (which splits after the first mitotic division), whereas fraternal twins are produced from separate sperm and separate egg cells. If two parents, one with brown eyes (a dominant trait) and the other with blue eyes (the recessive trait) produce one twin boy with blue eyes, what is the probability that a fraternal twin will transmit the blue eye allele to his or her offspring? Please give your answer as a single decimal
75%? If parents are Bb x bb, then sons have 50% chance of being bb, 50% Bb. That means a 75% chance for their babies to inherit the b allele... bc out of all alleles, Bb + bb, 75% = b
A recessive allele in mice results in an abnormally long neck. Sometimes, during early embryonic development, the abnormal neck causes the embryo to die. An experimenter began with a population of true-breeding normal mice and true-breeding mice with long necks. Crosses were made between these two populations to produce an F1 generation of mice with normal necks. The F1 mice were then mated to each other to obtain an F2 generation. For the mice that were born alive, the following data were obtained: 438 mice with normal necks 25 mice with long necks What percentage of homozygous mice (that WOULD HAVE HAD long necks IF they had survived) died during embryonic development?
82.9%
Assume that a dihybrid cross is made in which the genes' loci are autosomal, independently assorting, and incompletely dominant. How many different phenotypes are expected in the offspring?Answer as a single whole number (for example 2 or 4)
9
Jill is homozygous recessive for gene A and is going to have a child with Jack, who is heterozygous for gene A. Which of the following offspring genotypes could NOT result from fertilization of a normal haploid egg with a sperm that had undergone nondisjunction in meiosis II? AAa Aaa aaa aa a All of the above are possible
Aaa
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 (don't consider the Bombay Phenotype) ? Type A blood All of the blood types are possible Type B blood Type O blood Type AB blood
All of the blood types are possible
Many people who are heterozygous for a reciprocal translocation suffer from semisterility. Which of the following does not contribute to their partial loss of fertility? The amount of genetic material does not remain constant Adjacent-2 segregation Alternate segregation Adjacent-1 segregation
Alternate segregation
What stage of mitosis or meiosis is the following cell in given that the typical diploid number for this organism is six? Two sets of two sis chromatids (tetrads) being pulled apart to each side of the cell... 6 chromosomes total, 12 chromatids total, 3 chromosomes on either side of the cell.
Anaphase 1
Assuming no crossing over between the gene in question and the centromere, when do alleles segregate during meiosis? Anaphase II Metaphase II Metaphase I Prophase I Anaphase I Prophase II
Anaphase I
The longitudinal halves of a single chromosome that has undergone replication are known as what? Tetrads Chromatids Chaismata Homologs Centrosomes
Chromatids
The Notch mutation is a deletion on the X chromosome of Drosophila melanogaster. Female flies heterozygous for Notch have an indentation on the margins of their wings. Notch is lethal in the homozygous and hemizygous conditions. The Notch deletion covers the region of the X chromosome that contains the locus for white eyes, an X-linked recessive trait. Determine the phenotypes and proportions of progeny produced by the crosses listed in the table. Cross Parental Phenotypes A. Red-eyed notch fem x white-eyed male B. White-eyed notch fem x red-eyed male C. White-eyed notch fem x white-eyed male What proportion of progeny would you expect from each cross? 1) 1/3 red-eyed Notch females, 1/3 wild-type females, and 1/3 white-eyed males 2) 1/3 white-eyed females, 1/3 white-eyed Notch females, 1/3 white-eyed males 3) 1/4 Notch males, 1/4 red-eyed Notch females, 1/4 white-eyed females, 1/4 white-eyed males 4) 1/3 wild-type males, 1/3 wild-type females, 1/3 white-eyed Notch females 5) 1/3 wild-type males, 1/3 red-eyed Notch females, 1/3 white-eyed females Cross A _____ Cross B _____ Cross C _____
Cross A: 4 Cross B: 1 Cross C: 2
While doing research on deep-sea vents, you discover a very simple new life form. After some initial analysis, you find that this life form contains small fragments of DNA, small complementary RNA fragments, and proteins. Fortuitously, you collected two strains, one that is purple and one that is yellow. You wish to discover which of those three molecules could be the genetic material. You heat-kill some of the purple life form and subject three different homogenized samples to different enzymes: DNase, RNase, or protease. Which treated sample(s) will transform yellow into purple IF RNA is the genetic material? DNase DNase and Protease RNase and Protease DNase and RNase Protease RNase None of the Above
DNase and Protease
Shell coiling of the snail Lymnaea peregra results from a genetic maternal effect. An autosomal allele for a right-handed shell, D , called dextral, is dominant over the allele for a left-handed shell, d, called sinistral. In general, snails are hermaphroditic and reproduce as both males and females. However, a pet snail named Martha is sinistral and reproduces only as a female. Martha's Dad = S Martha's Mom = D Martha = S Martha's mans = S Martha's kids all = D Martha's sister = S Sister's mans = D Martha's sister's kids all = S From the pedigree above, determine Martha's genotype. DD Dd dd More than one of the genotypes is possible
Dd
Which of the following definitions is FALSE? Penetrance?the percentage of individuals in the population carrying the allele who actually express the phenotype associated with it Expressivity?the percentage of individuals in the population carrying the allele who do not express the phenotype associated with it Incomplete dominance?occurs when the phenotype of the heterozygote is an intermediate of the phenotypes of the homozygotes Codominance?occurs when multiple alleles exist for a given gene and more than one of them is dominant
Expressivity?the percentage of individuals in the population carrying the allele who do not express the phenotype associated with it
Assume that genes c and d are located on the same chromosome. On one chromosome, alleles c+ and d+ are found, while the homolog contains alleles c and d. Which of the following would be evidence of a recombination event? A. Alleles c+ and d+ together on one chromosome B. Alleles c and d together on one chromosome C. Alleles c+ and d together on one chromosome D. Alleles c and d+ together on one chromosome E. both choices A & B F. both choices C & D
F. both choices C & D
In a cross of a round hybrid pea with a true breeding round parent, what genotypic proportions would be observed in the offspring? All wrinkled All heterozygous Half round, half wrinkled All round Half heterozygous, half homozygous dominant None of the Above
Half heterozygous, half homozygous dominant
Which of the following statements about chromosomal inversions is NOT true? An inversion can break a gene into two parts and separate each to different locations. The expression of the gene may be altered due to the positional effect. Inversions don't affect the likelihood of producing viable gametes since there is no loss of genetic material. The individual organisms have neither lost nor gained any genetic material. The inversion mutations may not have pronounced phenotypic effects since there is no loss of genetic material.
Inversions don't affect the likelihood of producing viable gametes since there is no loss of genetic material.
If two genes do not undergo independent assortment they are said to be
Linked
Suppose a graduate student is studying a loss-of-function mutation in the mouse gene zigzag. Whereas wild type mice have straight tails, zigzag mutant mice have tails with two sharp kinks, so that the tail looks like the letter Z. To determine how the zigzag phenotype is inherited, he performs the crosses listed in the first column of the table below, using parents from true breeding lines. Five possible sets of results from these crosses are shown. Determine the mode of inheritance of the zigzag gene that would yield each result set and match it with the correct description. Each mode of inheritance will be used exactly once. 1) X-linked recessive inheritance 2)genomic imprinting (paternal allele is inactive) 3) cytoplasmic inheritance 4) genomic imprinting (maternal allele inactive) 5) maternal effect inheritance Mode 1 ___ Mode 2 ___ Mode 3 ___ Mode 4 ___ Mode 5___
Look at the whole diagram. Saved as screenshot on your desktop as "Exam 2 Question 37" Mode 1: 5 Mode 2: 4 Mode 3: 2 Mode 4: 3 Mode 5: 1
The mode of cell division that results in four daughter cells that are genetically different, with each cell containing one haploid set of chromosomes, is known as what? Somatic cell regeneration Interphase Binary fission Mitosis Meiosis
Meiosis
What is the gene order of linked genes M, N, O, and P, given the following recombination frequencies? M-N: 6% M-O: 12% M-P: 5% N-O: 18% N-P: 1% O-P: 17% ONPM MOPN PNMO NPMO
NPMO
The monomer building blocks of DNA are known as
Nucleotides
Suppose DNA polymerase synthesizes DNA at a rate of 1000 bases per minute in a newly discovered bacteria and that bacteria replicates 50% of their chromosome every 40 minutes. (pic of DNA molecule that is 2nm wide, has 0.34nm between base pairs [vertically], has 3.4nm per one full rotation [every 10 bps] ) Calculate the total number of nucleotides in the bacterial chromosome. Number of nucleotides:_________ Calculate the length of the entire bacterial chromosome using the appropriate information from the diagram of DNA. Length: ____________ nm
Number of nucleotides: 320000 Length: 54400 nm
A genetically important event called crossing-over occurs during what phase? Prophase II Metaphase II Prophase I Metaphase I Anaphase I
Prophase I
You are a research assistant working on the planet Blergon. There are two strains of bacteria in the lab known as SSB-1 and SSG-2, where SSB-1 is a toxic, flesh-eating bacteria that can be killed with heat. While SSG-2 is a completely safe strain of the bacteria. In the lab, SSB-1 is exposed to heat and it is now safe to touch. In three separate experiments, heat-treated SSB-1 is treated with different enzymes DNase, RNase, lipase, and protease. Each is then mixed with cultures of the SSG-2 strain. You find that the cultures treated with DNase, RNase, and Lipase will eat your flesh. However, the culture treated with protease is completely safe when you stick your hand in. based on this experiment, what is the transforming principle on planet Blergon? Protein RNA DNA Lipid All of the Above None of the Above
Protein
A coin is flipped 100 times, with a result of 53 heads and 47 tails. What is the deviation between the observed numbers and the expected 50-50 results called? Random sampling error Goodness of fit Standard error Degrees of freedom Probability None of the Above
Random sampling error
The portion of cell cycle during which the chromosomes are replicated is called what? Prophase G2 M S G1
S
You would like to know whether the progeny of a pair of mated fruit flies are distributed among the resulting four phenotypic classes in a 1:1:1:1 ratio. You perform a chi-square test and obtain a p-value of 0.04. Assuming you have done the test correctly, select the best interpretation of this result. The phenotypic ratio is actually 9:3:3:1 The differences between the observed and expected counts are too large to be attributed to chance. Approximately 4% of the offspring lie outside the range of values expected for a 1:1:1:1 ratio. The traits being studied are on separate chromosomes. All of the Above
The differences between the observed and expected counts are too large to be attributed to chance.
A cross between two pea plants with genotypes PpLl and PpLl results in an F1 generation that is 25% PPLL, 50% PpLl, and 25% ppll. Which reason most likely explains why other possible genotypes are not present? The loci of the genes are on different chromosomes. The genes underwent independent assortment The loci of the genes are close together on the same chromosome. Crossing over occurred between chromosomes. None of the Above
The loci of the genes are close together on the same chromosome.
Which of the following is not correct concerning epistatic interactions? They produce variations in the expected 9:3:3:1 ratio of a dihybrid cross. They involve a gene at one locus masking the effects of a gene at a different locus. They can be associated with enzymatic pathways. They are due to gene interactions. All of the above are correct. They always result in a 9:7 ratio of a dihybrid cross.
They always result in a 9:7 ratio of a dihybrid cross.
What can cause genes to move from one linkage group to another? Deletions Translocations Polyploidy Inversions homologous recombination
Translocations
If a cell has a diploid number of six before meiosis, how many chromosomes will be in each of the four daughter cells if one pair of chromosomes experiences nondisjunction during meiosis I? Two cells will have 4 chromosomes, two cells will have 2 chromosomes. Two cells will have 6 chromosomes, two cells will have none. Two cells will have 5 chromosomes, two cells will have 1 chromosome. All four cells will have 3 chromosomes.
Two cells will have 4 chromosomes, two cells will have 2 chromosomes.
What happens physically during the process of crossing over? -It is not known what occurs during crossing over. -Two homologous chromatids break and rejoin at precisely the same site along the chromosome so that there is no loss or gain of material on either product. -Two homologous chromatids break and rejoin at random sites along the chromosome. -The genetic information on one chromatid is replaced by copying genetic information from a homologous chromatid without any physical exchange between the chromosomes.
Two homologous chromatids break and rejoin at precisely the same site along the chromosome so that there is no loss or gain of material on either product.
Many of the color varieties of summer squash are determined by several interacting loci: AA or Aa gives white, aaBB or aaBb gives yellow, and aabb produces green. Assume that two fully heterozygous plants are crossed. Give the phenotypes and frequencies of the offspring.Express your answer out of 16 offspring (for example for 8/16 or 2/16) White_____ Yellow____ Green_____
White: 12/16 Yellow: 3/16 Green: 1/16
In Drosophila, sex is determined by a balance between the number of haploid sets of autosomes and the number of what? telomeres X chromosomes nucleolar organizers centromeres Y chromosomes
X chromosomes
Which of the following types of inheritance have the feature that an affected male could have all affected daughters but no affected sons? Autosomal recessive Y-linked X-linked dominant X-linked recessive Autosomal dominant
X-linked dominant
What gene is most responsible for X-inactivation? Xist Xce Tsix Xic
Xist
If you find a p-value of 0.49 from chi-squared analysis with an assumption of independent assortment, what would be your most appropriate conclusions? -You reject the null hypothesis, there is enough evidence to suggest something more than random sampling error is responsible for the differences observed, data ARE NOT consistent with independent assortment -You fail to reject the null hypothesis, there is NOT enough evidence to suggest something more than random sampling error is responsible for the differences observed, data ARE NOT consistent with independent assortment -You reject the null hypothesis, there is enough evidence to suggest something more than random sampling error is responsible for the differences observed, data ARE consistent with independent assortment -You fail to reject the null hypothesis, there is NOT enough evidence to suggest something more than random sampling error is responsible for the differences observed, data ARE consistent with independent assortment
You fail to reject the null hypothesis, there is NOT enough evidence to suggest something more than random sampling error is responsible for the differences observed, data ARE consistent with independent assortment
1 = Meiosis I, 2 = Meiosis II a. Sister chromatids separate in anaphase of Meiosis__. b. Down syndrome is an example of nondisjunction in Meiosis__. c. Homologous chromosomes separate in anaphase of Meiosis__. d. Results in haploid number of chromosomes in each of the daughter cells. e. Produces 4 unique daughter cells each with one copy of a chromosome at the end. f. Similar to mitosis. g. Paternal and maternal chromosomes assort randomly.
a. 2 b. 1 c. 1 d. 1 e. 2 f. 2 g. 1
Determine whether each statement is true or false: (1 = true, 2 = false) a. Crossing over is an event that occurs in Meiosis II and results in the exchange of genetic information between sister chromatids. b. The synaptonemal complex is the fusion of the sister chromatids at the start of Meiosis I. c. A chiasma (or chiasmata) is the place where crossing over occurs. d. Sister chromatids are not bivalent and therefore cannot form tetrads. e. Syanpsis is the fusion of chromosomes at the start of Meiosis I. f. If two chromosomes have similar positions, structures, and origins they are referred to as sister chromatids.
a. 2 b. 2 c. 1 d. 2 e. 1 f. 2
Species I is diploid (2n = 6) with chromosomes AABBCC; a related species II is diploid (2n = 6) with chromosomes MMNNOO. Indicate the chromosomes that would be found in individuals with the following chromosome mutations. At least one of the correct answers will not be available (choose "correct answer not shown") and not all answer choices will be used. 1)AAABBCC 2)MMNNNOO 3)AAABBBCCC 4)AABBCC; MMNNOO 5)MMMMNNNNOOOO 6)MMNNNNNOO 7)AAABBCCC 8)MMNN 9)correct answer not shown a. a nullisomic for chromosome O b. double trisomic for chromosomes A and C c. monosomic for chromosome A d. an allotetraploid e. an autotriploid of species I f. trisomic for chromosome A g. tetrasomic for chromosome N h. an autotetraploid of species II
a. 8 b. 7 c. 9 d. 4 e. 3 f. 1 g. 9 h. 5
In chickens, a condition referred to as "creeper" exists whereby the bird has very short legs and wings, and appears to be creeping when it walks. If creepers are bred to normal chickens, one-half of the offspring are normal and one-half are creepers. Creepers never breed true. If bred together, they yield two-thirds creepers and one-third normal. Propose an explanation for the inheritance of this condition. a. According to the given data, one would expect the creeper trait to be dominant for the creeper trait and a recessive in terms of lethality. Normal birds would be homozygous for the recessive trait. b. According to the given data, one would expect the creeper trait to be recessive for the creeper trait but dominant in terms of lethality. Normal birds would be homozygous for the dominant trait. c. According to the given data, one would expect the creeper trait to be recessive for the creeper trait and normal birds are heterozygous. The lethal phenotype is homozygous dominant. d. According to the given data, one would expect the creeper trait to be dominant for the creeper trait and dominant in terms of lethality. Normal birds would be homozygous for the recessive trait.
a. According to the given data, one would expect the creeper trait to be dominant for the creeper trait and a recessive in terms of lethality. Normal birds would be homozygous for the recessive trait.
A spineless (no wing bristles) female fly is mated to a male that is claret (dark eyes) and hairless (no thoracic bristles). Phenotypically wild-type F1 female progeny were testcrossed, and the following progeny (1000 total) were observed. Which gene is in the middle? Phenotypes Number Observed Spineless 321 Wild 38 Claret, spineless 130 Claret 18 Claret, hairless 309 hairless, claret, spineless 32 hairless 140 hairless, spineless 12 a. Hairless b. Claret c. Spineless
a. Hairless
Which of the following is false regarding mtDNA? a. It is a linear chromosome b. it mostly contains rRNA and tRNA genes c. Multiple copies exist in each mitochondriaIt d. is around 17,000 bp in length
a. It is a linear chromosome
Which of the following descriptions is NOT true of heterochromatin? a. It makes up most chromosomal material and is where most transcription occurs. b. It is characterized by the absence of crossing over and replication late in the S phase. c. It occurs along one entire X chromosome in female mammals when this X becomes inactivated. d. It exists at the centromeres and telomeres. e. It remains in a highly condensed state throughout the cell cycle.
a. It makes up most chromosomal material and is where most transcription occurs.
Although the most frequent forms of Down syndrome are caused by a random error, nondisjunction of chromosome 21, Down syndrome occasionally runs in families. What is the cause of this form of familial Down syndrome? a. a translocation between chromosome 21 and another small chromosome b. too many X chromosomes c. an inversion involving chromosome 21 d. a chromosomal aberration involving chromosome 1 e. a maternal age effect
a. a translocation between chromosome 21 and another small chromosome
Which of the following terms should NOT be used to describe a human with three copies of chromosome 12? a. 2n+1 b. Triploid c. Aneuploid d. Trisomy 12 e. All of the Above
b. Triploid
Through the study of mitochondrial disorders, scientists have suggested a link between the decline of mitochondrial function and aging. What process appears to be involved in this suspected phenomenon? a. recombination of mtDNA and nuclear DNA b. accumulation of mutations in the mtDNA c. accumulation of sporadic mutations in the nuclear genome d. recombination among mtDNAs of different mitochondria e. decline of mutations in the nuclear genome
b. accumulation of mutations in the mtDNA
The classic Hershey and Chase (1952) experiment that offered evidence in support of DNA being the genetic material in bacteriophages made use of which of the following radioisotopes to label the proteins? a. phosphorus b. sulfur c. nitrogen d. hydrogen e. A and B
b. sulfur
In fruit flies, the recessive pr and cn mutations cause brown and bright-red eyes, respectively (wild-type flies have brick-red eyes). The double mutant pr-cn combination has orange eyes. An F1 female who is wild-type is crossed to an orange-eyed male. Their F2 progeny have the following distributions: Phenotype Observed wild type 8 brown 241 bright-red 239 orange 12 Total 500 Which classes are the parental types (not the same thing as the parents)? wild-type and orange brown and bright-red wild-type and brown there is no way to determine this bright-red and orange
brown and bright-red
Predict the potential effect of the Lyon hypothesis on the retina of a human female heterozygous for the X-linked red-green color blindness trait. a. X chromosome inactivation is influenced by methylation patterns inherited from the parents. When the chromosome with the X-linked red-green color blindness trait is obtained from the mother, then female offspring will not be affected. If it's obtained from the father, then they will be affected. b. If descendants of the cells with the X-linked red-green color blindness trait participate in the further development of the retina, females will not be affected. c. Females will display mosaic retinas with patches of defective color perception and surrounding areas with normal color perception. d. Females will be fully color blind.
c. Females will display mosaic retinas with patches of defective color perception and surrounding areas with normal color perception.
Which of the following statements about histones and gene expression is CORRECT? a. Phosphorylation of cytosines generally leads to increase in transcription. b. Addition of methyl groups to the tails of histone proteins always results in activation of transcription. c. In a general sense, highly condensed DNA bound with histone proteins represses gene expression. d. Histone code refers to the modification that takes place on the globular domain of the octamer histone core. e. Acetylation involves the addition of acetyl groups to histone proteins, and it usually results in repression of transcription.
c. In a general sense, highly condensed DNA bound with histone proteins represses gene expression.
Because of the number of hydrogen bondsthat hold the two strands of a DNA molecule together, unique strands require varying amounts of energy to be separated. Because of this, each unique DNA molecule ?melts? at a different temperature. In this context, Tm, melting temperature, is the point atwhich two strands separate, or become denatured. Which DNA sequence listed below would have the lowest Tm? a. GGCGCACC b. CTAACTGG c. TATTGTCT d. GACTCCTG
c. TATTGTCT
Which of the following statements regarding the Drosophila Bar phenotype is NOT true? (In the pic, more bar bodies = smaller eyes. The additional bar bodies show up in the q (bottom half of the chromatid.) a. The balance of gene product is critical to cell function and normal development. b. The Bar phenotype reflects the genetic phenomenon called gene dosage effect. c. The trait is a result of a pericentric inversion. d. The more Bar segment copy the fly has, the more reduced the facets in the eyes get. e. Unequal crossing over event may give a rise to the duplication of the Bar region.
c. The trait is a result of a pericentric inversion. (not inversion at all. It is a duplication)
A ribosomal RNA gene is an example of which type of DNA sequence in eukaryotes? a. short interspersed elements b. unique-sequence DNA c. moderately repetitive DNA d. long interspersed elements e. highly repetitive DNA
c. moderately repetitive DNA
What is the base sequence of a DNA strand that is complementary to 5'-ATCGGATTC-3' sequence (be sure to pay attention to 5? and 3? ends)? a. 5'-CTTAGGCTA-3' b. 5'-ATCGGATTC-3' c. 5'-TAGCCTAAG-3' d. 5'-GAATCCGAT-3'
d. 5'-GAATCCGAT-3'
A human embryo is produced by the fusion of two gametes that have a normal complement of sex chromosomes. This individual develops into an adult and is diagnosed with Turner syndrome. How can this be? a. Nondisjunction produced a gamete that lacked any sex chromosome. This gamete was fertilized, which resulted in the individual with Turner syndrome. b. This individual is a gynandromorph with a mixture of both male and female characteristics. c. A reciprocal translocation between the X chromosome and an autosome resulted in a change in the location of one of the X chromosomes. d. An X chromosome was lost soon after fertilization, leading to a mosaic individual with a mixture of XX and XO cells. e. The embryo was exposed to colchicine soon after fertilization, which produced a polyploidy individual. Dosage compensation caused an imbalance between autosomal and X chromosome gene expression.
d. An X chromosome was lost soon after fertilization, leading to a mosaic individual with a mixture of XX and XO cells.
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 H after: A C D * E F G H a. Gene duplication b. Terminal deletion c. Inversion d. Interstitial deletion
d. Interstitial deletion
What are the monomer building blocks of DNA know as? a. lipids b. carbohydrates c. amino acids d. nucleotides e. proteins
d. nucleotides
Shell coiling of the snail Lymnaea peregra results from a genetic maternal effect. An autosomal allele for a right-handed shell, D , called dextral, is dominant over the allele for a left-handed shell, d, called sinistral. In general, snails are hermaphroditic and reproduce as both males and females. However, a pet snail named Martha is sinistral and reproduces only as a female. Martha's Dad = S Martha's Mom = D Martha = S Martha's mans = S Martha's kids all = D Martha's sister = S Sister's mans = D Martha's sister's kids all = S From the pedigree above, determine Martha's sister's genotype. DD Dd dd More than one of the genotypes is possible
dd
Shell coiling of the snail Lymnaea peregra results from a genetic maternal effect. An autosomal allele for a right-handed shell, D , called dextral, is dominant over the allele for a left-handed shell, d, called sinistral. In general, snails are hermaphroditic and reproduce as both males and females. However, a pet snail named Martha is sinistral and reproduces only as a female. Martha's Dad = S Martha's Mom = D Martha = S Martha's mans = S Martha's kids all = D Martha's sister = S Sister's mans = D Martha's sister's kids all = S From the pedigree above, determine Martha's Mom's genotype. DD Dd dd More than one of the genotypes is possible
dd
In many species, there are two representatives of each chromosome. In such species, what is the characteristic number of chromosomes called and how is it usually symbolized? haploid number or 2n diploid number or n diploid number or 2n haploid number or n None of the Above
diploid number or 2n
Chimpanzees, gorillas, and orangutans all have 48 chromosomes, whereas humans have 46. Human chromosome 2 is a large, metacentric chromosome with G-banding patterns that closely match those found on two different acrocentric chromosomes of the apes. Which statement would BEST explain these findings? a. Meiotic nondisjunction gave rise to a nullisomic gamete. The fusion of two nullisomic gametes produced the ancestor of the human species with 46 chromosomes instead of 48. b. Humans have the correct number of chromosomes. The extra chromosome pair in the other apes is a classic case of tetrasomy as a result of meiotic nondisjunction in the primate ancestor. c. Infection by a primate virus created a new chromosome when the viral DNA became a permanent part of the genome. Humans were not affected by this virus, so they did not acquire the extra chromosome. d. A nonreciprocal translocation and subsequent fusion of the chromosomal fragments created a genome of 46 chromosomes without the loss of any genetic information. e. A translocation took place in a human ancestor, creating a large metacentric chromosome from the two long arms of the ancestral acrocentric chromosomes. The other small chromosome produced by this translocation was lost.
e. A translocation took place in a human ancestor, creating a large metacentric chromosome from the two long arms of the ancestral acrocentric chromosomes. The other small chromosome produced by this translocation was lost.
Which statement is NOT true of negatively supercoiled DNA? a. It is the most common state of DNA in bacteria cells b. It has less turns than a relaxed DNA molecule of the same size. c. It eases the separation of nucleotide strands during replication and transcription. d. It allows DNA to be packed into small spaces. e. It has less than 10 bp per turn of its helix.
e. It has less than 10 bp per turn of its helix.
Crossing over is more likely to occur between genes that are: close together on a chromosome far apart on a chromosome it depends on the types of genes there is no correlation
far apart on a chromosome
In many organisms, one set of chromosomes comes from the maternal parent, while the other set comes from the paternal parent. Similar chromosomes in these sets are said to be: alleles morphs homologous sister chromatids haploid
homologous
In dihybrid crosses, the ratio 9:3:3:1 ratio indicates intermediate dominance independent assortment linked genes multiple alleles codominance
independent assortment
Which of the following is primarily responsible for the maternal effect? maternal phenotype maternal genotype mitochondria sperm cells
maternal genotype
In Drosophila, an individual female fly was observed to be XXY and to have white eyes as contrasted with the normal red eye color of wild type. The female's parents were wild type. The mother, however, was heterozygous for the gene for white eyes.Knowing that white eyes are X-linked and recessive, in which parent and at what stage did nondisjunction occur to produce this XXY, white-eyed female fly? meiosis II in the father meiosis II in the mother meiosis I in the father meiosis I in the mother more than one of these answers
meiosis II in the mother
You are a research assistant in a lab that studies nucleic acids. Your advisor gave you four tubes for analysis. Each of these tubes differs in its contents by the source of its nucleic acids: mouse cytoplasm (single-stranded RNA), yeast nuclei (double-stranded DNA), rotavirus (double-stranded RNA), and parvovirus (single-stranded DNA). The approximate nucleotide base composition of each sample is given in the table below. Nucleic Acids Tube A C U T G 1 32 17 0 32 19 2 37 20 13 0 30 3 22 18 0 27 33 4 33 16 34 0 17 mouse cytoplasm = tube ___ yeast nuclei = tube___ rotavirus = tube ___ parvovirus = tube ___
mouse cytoplasm = tube 2 yeast nuclei = tube 1 rotavirus = tube 4 parvovirus = tube 3
DNA wraps around histone and other proteins to form ______________ which can be seen as "beads on a string" in an electron micrograph.
nucleosomes
In fruit flies, the recessive pr and cn mutations cause brown and bright-red eyes, respectively (wild-type flies have brick-red eyes). The double mutant pr-cn combination has orange eyes. An F1 female who is wild-type is crossed to an orange-eyed male. Their F2 progeny have the following distributions: Phenotype Observed wild type 8 brown 241 bright-red 239 orange 12 Total 500 What is the genotype of the mother (F1) of these progeny (F2)? prcn+/prcn+ prcn/prcn pr+cn/pr+cn prcn/pr+cn+ pr+cn/prcn+
pr+cn/prcn+
In fruit flies, the recessive pr and cn mutations cause brown and bright-red eyes, respectively (wild-type flies have brick-red eyes). The double mutant pr-cn combination has orange eyes. An F1 female who is wild-type is crossed to an orange-eyed male. Their F2 progeny have the following distributions: Phenotype Observed wild type 8 brown 241 bright-red 239 orange 12 Total 500 The F1 mother of these progeny (F2) resulted from a cross between two flies from true breeding lines (P generation). What are the genotypes of these two lines? prcn+/prcn+ and pr+cn/pr+cn pr+cn/prcn and pr+cn+/prcn pr+cn+/prcn and prcn/prcn pr+cn+/pr+cn+ and prcn/prcn
prcn+/prcn+ and pr+cn/pr+cn
How would you describe the arrangement of alleles in the following example? c+ & d together on one chromosome and c & d+ together on the other chromosome. complementation coupling epistasis homozygous repulsion
repulsion
The nucleolus is important for which process? gamete formation transcription chromosome packaging ribosome assembly metabolism None of the Above
ribosome assembly
Which of the following is entirely composed of genetic material that is 100% identical (not including crossing over or new mutations)? homologous chromosomes sister chromatids X & Y chromosomes A & B All of the Above
sister chromatids
What sort of cross would be the most effective to determine if an organism with a dominant phenotype is homozygous or heterozygous? dihybrid cross self-fertilization test cross reciprocal cross None of the Above
test cross
RNA is formed by what process? reverse translation translation reverse transcription transcription replication
transcription
Polydactyly is the condition of having extra fingers or toes. Some polydactylous persons possess extra fingers or toes that are fully functional, whereas others possess only a small tag of extra skin. This is an example of complementation. Incomplete penetrance. complete dominance. variable expressivity. independent assortment.
variable expressivity.
