BSCI222 Genetics Final

Which of the following statements about centromeres is false? They are composed of satellite DNA packed as heterochromatin They hold sister chromatids together They are essential for separation of the chromatids in mitosis and meiosis "Lower" eukaryotes are associated with complex sequences and modified histones, while "higher" eukaryotes are associated with conserved DNA sequences

"Lower" eukaryotes are associated with complex sequences and modified histones, while "higher" eukaryotes are associated with conserved DNA sequences

RF equation

(# of recombinants) / (# of total progeny)

Assume both parents are ET/et, and the recombination frequency is 30%. What is the chance of a child having the Et/Et genotype? .09 .7225 .49 .0225

.0225

Assume that the mother's genotype is AZ/az, and the father's genotype is Az/aZ, and the recombination rate is 10%. What are the probabilities of an 'az' gamete from each parent? .1 from mom, .05 from dad .5 from mom, 0 from dad .45 from mom, .05 from dad .4 from mom, .1 from dad

.45 from mom, .05 from dad

Suppose in humans, brown eyes are dominant over blue eyes. If a homozygous dominant father has a child with a a heterozygous woman, what is the probability that the child will have blue eyes?

0%

Suppose in humans, brown eyes are dominant over blue eyes. If a homozygous dominant father has a child with a a homozygous recessive woman, what is the probability that the child will have blue eyes?

0%

You completed a three-point cross and found that the expected number of double recombinants was 88 and the observed number of double recombinants was 74. Calculate the interference and interpret the result. 0.16; one crossover has little to no effect on the other crossover 0.84; 0.65; one crossover greatly reduces the probability of the second crossover 0.84; one crossover has little to no effect on the other crossover 0.16; 0.65; one crossover greatly reduces the probability of the second crossover

0.16; one crossover has little to no effect on the other crossover

If that one parent is GG and the other is gg, what is the probability that their child offspring will be heterozygous?

1

You are following segregation of five unlinked genes in a cross - A, B, C, D and E. Dominant alleles are capital letters and recessive are lower case. Being homozygous recessive for all five genes produces a multigenetic trait such as bipolar disorder. Two unaffected parents with the genotypes - Aa bb Cc Dd Ee x aa Bb Cc dd Ee mate. What is the frequency expected for one child to have the affected genotype of being all homozygous recessive genotype - aa bb cc dd ee?

1/128

A couple has four children. What is the probability that they would have four boys?

1/16

A couple has three children, all of whom have brown eyes and blond hair. Both parents are homozygous for brown eyes (BB), but one is a blond (rr) and the other is a redhead (Rr). What is the probability that their next child will be a brown-eyed redhead?

1/2

On your own, make a Punnett square for the following cross: FFWw x FfWW. What fraction of offspring should be type FFWW?

1/4

Two gene loci, A and B, assort independently, and alleles A and B are dominant over alleles a and b. Indicate the probability of producing an AB gamete from an AaBb individual.

1/4

If a double-stranded DNA molecule of 50 base pairs contains 15 cytosine bases (C), how many thymine bases will it have? 10 30 15 20

10

If a cross is made between two plants that are heterozygous for two traits (AaBb), then their offspring should follow the 9:3:3:1 ratio. In this case, A is the dominant allele for long stems, and B is the dominant allele for wrinkled seeds. If the two parents were crossed to yield 320 progeny, approximately how many plants with long stems and wrinkled seeds would you expect?

180

Which of the following pieces of DNA is going to be easier to separate into single stranded molecules using heat (ie, have a lower melting point), which breaks hydrogen bonds? Why? 1. 5' ATTTTCCGTAAT 3' 3' TAAAAGGCATTA 5' 2. 5' ACGGTTTACCGG 3' 3' TGCCAAATGGCC 5' 2; it has more C-G pairs which are connected by three hydrogen bonds instead of two, so they are easier to break. 2; it has more C-G pairs which are connected by two hydrogen bonds instead of three, so they are easier to break. 1; it has more A-T pairs which are connected by one hydrogen bond instead of two, so they are easier to break. 1; it has more A-T pairs which are connected by two hydrogen bonds instead of three, so they are easier to break.

1; it has more A-T pairs which are connected by two hydrogen bonds instead of three, so they are easier to break.

How many phenotypes result from a dihybrid cross involving completely linked genes (i.e., no crossover)? 9:3:3:1 4 6 2

2

If restriction enzyme A has 2 recognition sites and enzyme B has 3 recognition sites, how many bands would you expect to see in the gel lane for enzyme A after digesting a plasmid? For enzymes A + B? (Note: you are assuming none of the fragments are the same length) 2 bands; 3 bands 3 bands; 6 bands 2 bands; 5 bands 3 bands; 5 bands

2 bands; 5 bands

If the recombination frequency between genes A and B is 20%, how many map units apart are they? 0.20 map units 80 map units 0.80 map units 20 map units

20

In avocets, curved beaks result from a Z-linked recessives gene. A curve-beak male is mated with a flat-beaked (normal) female. The F1 are interbred to produce the F2. What is the probability of producing a curve-beak female in the F2? What is the probability of producing a normal male in the F2?

25%; 25%

A testcross was performed between a plant that was heterozygous for 3 genes and one that was homozygous recessive for the genes. The offspring were scored for the three phenotypes. The results are shown below, expressed in symbolic terms: Type Number abC 24 ABc 19 aBc 9 AbC 8 abc 307 ABC 370 Abc 128 aBC 135 TOTAL 1000 The genes are listed in order (A B C). What is the distance in map units between A and B? 0.26 28 26 0.28

28

As part of a lab experiment, you create a two-locus cross between two plants, and you expect to see a 3:3:3:7 ratio of offspring. You determine the phenotype for 160 offspring, and find the proportions 30:29:31:70. If you use a chi-square test to determine whether the offspring do indeed fit this pattern, how many degrees of freedom would the test have?

3

The mosquito Aedes aegypti has a diploid number of 6 chromosomes. How many DNA molecules and Chromosomes are found per cell when this cell is progressing through the following stage: After Telophase II of Meiosis the cell has ___ DNA molecules and ___ Chromosomes

3, 3

If the probability that a bird will lay an egg is 75%, the probability that the egg will hatch is 50%, and the probability that the chick will be eaten by a snake before it fledges is 20%, what is the probability that a parent will have progeny that survive to adulthood?

30%

You play a game at a carnival in which you pick from among three shells; if a prize is under the shell that you choose then you keep the prize, and otherwise you get nothing. Only one of the three shells will have a prize under it. The carnival worker uses several different prizes: a coin 8% of the time, a bottle cap 80% of the time, and a hermit crab 12% of the time. If you play once, what is the chance that you will win a crab?

4%

You roll two dice (each die has six sides). What is the probability that you won't roll a 1 or a 6 on either die?

44.4%

Imagine a dihybrid cross. If there are 80 progeny (we are talking about snails here), approximately how many snails would you expect to be homozygous recessive for both traits?

5

The single strand of DNA below forms a stem-loop structure with a loop that is 5 nucleotides long. 5' - C T A C G A T __ __ __ __ __ __ __ __ - 3' What are the rest of the nucleotides? 5' - CTACGATG - 3' 5' - GCCCGTAG - 3' 5' - GTAGCATC - 3' 5' - GATGCCCG - 3'

5' - GCCCGTAG - 3'

The following DNA sequence is at the start of a DNA strand: 3'—AATTCGAGATTCA—5'. Which of the primer sequences below would be synthesized from this strand by DNA primase to initiate DNA replication? 5'—TTAACGTCTAAGT—3' 3'—TTAACGTCTAAGT—5' 5'—UUAAGCUCUAAGU—3' 3'—UUAAGCUCUAAGU—5'

5'—UUAAGCUCUAAGU—3'

Suppose in flies, red eyes are dominant over brown eyes. If for this trait, a homozygous recessive fly is mated with a heterozygous fly, what is the probability that the fly will have brown eyes?

50%

What is the maximum rate of crossover? There is no maximum rate of crossover 50% or 50 map units The maximum rate of crossover depends on the two genes. 100% or 100 map units

50% or 50 map units (Remember that at a rate of 50% or more, you can't tell the difference between linked genes that are really far apart and unlinked genes.)

If two loci R/r and W/w are linked and are 14 map units apart, and an Rw/rW individual is test-crossed, you expect to obtain: 14% rW individuals 86% Rw individuals 7% Rw individuals 7% rw individuals 14% RW individuals 43% rw individuals

7% rw individuals

Which of the following about a ladder used during gel electrophoresis is correct? A ladder is composed of a plasmid of unknown size. A ladder is composed of pieces of DNA of known length. A ladder is composed of pieces of DNA of unknown length. A ladder is composed of a plasmid of known size.

A ladder is composed of pieces of DNA of known length.

What is an allele?

A version of a gene that includes some SNPs

Determine the correct order of the genes on the chromosome, given the following information: Genes A and T cross over at a rate of 18% Genes M and T cross over at a rate of 9 % Genes A and H cross over at a rate of 11% Genes M and H cross over at a rate of 2% AMHT MATH TAMH TMAH

AMHT

Which of the following crosses will lead to a 9:3:3:1 ratio of phenotypes?

AaBb x AaBb

What is meant by the term dihybrid?

An organism that is heterozygous for two genes of interest

Which of the following is NOT a common characteristic seen in pedigrees for an X-linked recessive trait? Appears more in females than males Frequently skips a generation Does not pass from father to so

Appears more in females than males

Assuming crossing over has not occurred, Mendel's law of independent assortment is associated with which of the following: A. S- phase B. Meiosis I C. Anaphase of Mitosis D. Meiosis II

B

By convention, when the difference between the observed experimental outcome and the expected outcome is less than 5 percent (< 0.05), the experimental results are considered to be A. within the normal range. B. statistically significant and different from the expected outcome. C. less than one standard deviation from the mean. D. not significant.

B

Ginny Weasley is attempting to breed her pygmy puff, Arnold, who is pink & fuzzy to her friend's pygmy puff, which is purple and short-haired. She knew only that pink and fuzzy are both dominant traits, and when she breeds the two, they produce the following progeny: Pink, fuzzy: 541 Pink, short-haired: 350 Purple, fuzzy: 310 Purple, short-haired: 152 Given an a hypothesis of 1:1:1:1 and an calculated Chi square of 226.85, determine the degrees of freedom and whether you can accept or reject your hypothesis. https://people.smp.uq.edu.au/YoniNazarathy/stat_models_B_course_spring_07/distributions/chisqtab.pdf A. 2; accept (fail to reject) the null hypothesis B. 3; reject the null hypothesis C. 4; accept (fail to reject) the null hypothesis D. 2; reject the null hypothesis E. 4; reject the null hypothesis F. 3; accept (fail to reject) the null hypothesis

B

If one finds an individual with the dominant phenotype, it could have either a homozygous or heterozygous dominant genotype. A testcross with a homozygous recessive produces a phenotype(s) and ratios of ____________________ if it was heterozygous, or ________________ if it was homozygous. A. all dominant; ¾ dominant and ¼ recessive B. ½ dominant and ½ recessive; all dominant C. ¾ dominant and ¼ recessive; all dominant D. all dominant; ½ dominant and ½ recessive

B

In the world of Weeping angels, those with pointy wings are (A_), while those with round wings are (aa). In the efforts to explore this extraordinary species, you wish to determine the genotype of a pointy winged angel. Luckily you have trapped a round winged angel. What type of cross must you perform to determine the unknown genotype? A. Dihybrid cross B. Test Cross C. Metacross D. Reciprocal Cross

B

Which of these events is not mutually exclusive? A. the chance that you will study for the test in Dallas or in Chicago. B. the chance that you will eat garlic bread or spaghetti for dinner. C. the chance that you will get a heads or tails when you flip a coin. D. the chance that you you will pass or fail genetics.

B

DNA in the cell, with a right handed helix and 10 base pairs (BP) per helical turn, is in the: B form Single-stranded form Z form A form

B form

Which Law would you use to answer the following question: What is the chance of flipping a coin and getting three heads in a row? (NOTE: H1 = heads on the first roll, H2 = heads on the second roll, etc.) A. P(3 heads in a row) = P(H1) + P(H2) + P(H3) B. P(3 heads in a row) = P(H1) x P(H2) x P(H3)

B. (and = multiplication)

You have a 15kb plasmid. EcoRI cuts the plasmid at positions 7kb and 8kb, and BamHI cuts the plasmid at positions 1kb and 14kb. If you do a double digest with both EcoRI and BamHI on your plasmid, which of the following band patterns are possible on your gel? (hint: draw it!) Bands at 2kb, 7kb, and 8kb. Bands at 1kb, 2kb, and 7kb. Bands at 1kb, 2kb, and 6kb. Bands at 1kb, 7kb, 8kb, and 14kb.

Bands at 1kb, 2kb, and 6kb.

You have a 10kb plasmid. If your enzyme cuts the plasmid at three different recognition sites, which of the following band patterns are possible on your gel? Bands at 3kb, 4kb, and 5kb Bands at 2kb and 6kb Bands at 1kb and 5kb Bands at 1kb, 2kb, and 5kb

Bands at 2kb and 6kb

You have a 20kb plasmid. EcoRI cuts the plasmid at the 2kb point and at the 18kb point, while BamHI cuts the plasmid at the 5kb point and the 15kb point. What band pattern would you see on a gel when you cut the plasmid with both restriction enzymes at the same time? (hint: draw it!) Bands at 2kb, 3kb, 5kb and 10kb. Bands at 2kb, 4kb and 10kb. Bands at 2kb, 5kb, 15kb and 18kb. Bands at 3kb, 4kb and 10kb.

Bands at 3kb, 4kb and 10kb.

In Vulcans, black hair and pointy ears are dominant traits. Pollar has black hair but rounded ears. Damak, his mate, has red hair and pointed ears. Their first child, T'Pal, has red hair and rounded ears. Their second child, Spock, has black hair and pointed ears. Use EE or Ee for pointed ears and BB or Bb for black hair and answer the following: What is Pollar's genotype?

BbEe

If you were to accept the null hypothesis in a chi-square test, what would you conclude? A. The observed values do not "fit" within the range of expected values, and any variation has a significant cause. B. The observed values do not "fit" within the expected values, and any variation is due to chance. C. The observed values "fit" within the range of expected values, and any variation is due to chance. D. The observed values "fit" within the range of expected values, and any variation has a significant cause.

C

Which of these pairs are not independent of each other? A. The probability that your favorite color is green and your favorite sport is baseball. B. The probability that you will go to a party on Friday night and that your hair is brown. C. The probability that it will rain and the probability that you will (most likely) get wet if you are standing outside with no umbrella in a rainstorm. D. The probability that when you roll a dice, you will first roll a 6 and then a 2.

C

Which of these properly reflects the Law of Or? A. P(E1 or E2) = [P(E1) + P(E2)]/ [P(E1) + P(E2)] B. P(E1 or E2) = P(E1) + P(E2) C. P(E1 or E2) = P(E1) - P(E2) D. P(E1 or E2) = P(E1) * P(E2)

C???

You've isolated neon green cockroaches under the kitchen sink and have been examining them. You wish to determine if this color is transmitted in simple Mendelian fashion. You cross the neon green with your basic brown cockroach and end up with all Brown cockroaches. You allow the F1 to self and observe the following: Neon green: 26 Brown: 58 Based on what you've observed you predict a ratio of 1:3. What are your expected values? (Neon green, Brown) A. 54, 30 B. 25, 75 C. 63, 21 D. 21, 63

D

What would occur if there was a mutation in helicase that made it non-functional? DNA replication proceeds without any alteration. DNA builds up torsional strain. DNA will prevent reannealing. DNA cannot move past replication fork or bubble.

DNA cannot move past replication fork or bubble

Hagrid is at it again - he's been breeding dragons illegally for the last few years! His dragons are all Hungarian Horntails, but some are polka-dotted and some are not. Hagrid wants to create a true-breeding polka-dotted line of dragons, but whenever he crosses two polka-dotted dragons, he gets 2/3 polka-dotted and 1/3 solid-colored dragons. What is going on? Dragon patterning is controlled by a incompletely dominant allele. Dragon patterning is controlled by a codominant allele. Dragon patterning is controlled by a recessive lethal allele. Dragon patterning is controlled by a dominant lethal allele

Dragon patterning is controlled by a recessive lethal allele.

A gene has two alleles, E and e. Another gene also has two alleles, T and t. Which of the following correctly shows linkage between the two genes? ET/et Te/Et Ete/T Ee/tT

ET/et

Which type of chromatin makes light bands? Does this type usually contain more or less active genes? Heterochromatin; less active genes because the DNA is more tightly packed Euchromatin; more active genes because DNA is less tightly packed Euchromatin; less active genes because DNA is more tightly packed Heterochromatin; more active genes because DNA is less tightly packed

Euchromatin; more active genes because DNA is less tightly packed

Which of the following statements regarding penetrance and expressivity is/are correct? (multiple) Expressivity describes the extent to which you show a trait. Penetrance describes the extent to which you show a trait. Expressivity describes whether or not you have a trait if you have the genotype associated with it. Penetrance describes whether or not you have a trait if you have the genotype associated with it.

Expressivity describes the extent to which you show a trait. AND Penetrance describes whether or not you have a trait if you have the genotype associated with it.

A scientist usually accepts a p-value (or alpha level) of 0.15 as the threshold value to reject the null hypothesis. (true or false?)

False

True or False: The number of nucleotides between two genes that are 34 map units apart in Drosophila is the same as the number of nucleotides between two genes that are 34 map units apart in humans.

False

A Punnett square for a cross involving 2 genes (each with 2 alleles) has 4 rows and 2 columns.

False; it has 4 rows and 4 columns

How does histone acetylation change chromatin structure? Histones lose their negative charge so the positively charged DNA is more tightly packed Histones lose their positive charge so the negatively charged DNA is more tightly packed Histones lose their negative charge so the positively charged DNA is less tightly packed Histones lose their positive charge so the negatively charged DNA is less tightly packed

Histones lose their positive charge so the negatively charged DNA is less tightly packed

G2

In the figure below, which of the following letters depicts the point where the cell ensures that its DNA is undamaged before progressing to the next phase?

anaphase; mitosis

In the following picture of a 2n=4 cell, this is stage ________________ of __________________.

Determine the correct order of the genes on the chromosome, given the following information: Genes A and D cross over at a rate of 22% Genes A and L cross over at a rate of 5% Genes L and D cross over at a rate of 27% LDA ADL LAD DLA

LAD

Select the correct cell division phase according to its description: _________ Single Chromosomes align along the equatorial plane of the nucleus _________ Synapsis Occurs

Metaphase II, Prophase I

Which of the following is true about short tandem repeats? There are 2 types: minisatellites and microsatellites More than one of these are true None of these are true They are often found on telomeres to help protect genes against degradation They are used for DNA fingerprinting

More than one of these are true

A mistake in mitosis or meiosis where one chromosome does not separate as usual so that the resulting cells gain or loss of a chromosome is called:

Nondisjunction

Which of the following is the correct equation for calculating recombination frequency (RF)? RF = (# of total progeny) / (# of recombinants) RF = (# of linked) / (# of unlinked) RF = (# of recombinants) / (# of total progeny) RF = (# of recombinants) / (# of non-recombinants)

RF = (# of recombinants) / (# of total progeny)

Which technique would you use to determine if the sex of the parent passing on a gene affects the inheritance pattern? Test Cross Recombination Test Reciprocal Cross Karyotype

Reciprocal Cross

What are the implications of a nonfunctioning gyrase? Priming of the DNA does not occur therefore no replication. Topoisomerase degrades the DNA strand. Some replication occurs Replication is discontinued due to extensive torsional strain

Replication is discontinued due to extensive torsional strain

A molecule has the following percentages of bases: A= 42%, C = 14%, G= 21% and T=23%. Which of the following molecules best fits the description? Double-stranded DNA Single-stranded RNA Double-stranded RNA Single-stranded DNA

Single-stranded DNA

What is the fundamental difference between mitosis and meiosis?

The amount of genetic material per cell is cut in half in meiosis but remains constant in mitosis.

What is the null hypothesis

The hypothesis that any patterns in the observed data is due to chance alone and therefore not significant.

Which of the following is true about distance in genetic maps and distance in physical maps? Choose the best answer. Genetic map distance can be mathematically converted to physical distance by multiplying by a known standard value. The order of genes is the same in each type of map. The same data is used to make both types of maps. There is no difference between these.

The order of genes is the same in each type of map

If an uncut plasmid travels much faster through a gel than expected, but still only gives you one band, what could be the potential explanation? The plasmid supercoiled, and therefore was able to move through the gel much more quickly than expected. The plasmid was mistakenly loaded at the bottom of the gel near the positive electrode, so when electricity was added to the gel, the plasmid traveled upwards instead of downwards. Therefore, it appears that the plasmid traveled farther than it actually did. The plasmid was only cut at a single restriction site, instead of being cut at all of the possible restriction sites. Therefore, the single linear piece of DNA was able to move through the gel more easily than a circular plasmid could.

The plasmid supercoiled, and therefore was able to move through the gel much more quickly than expected.

Which of these is a possible explanation for a cut plasmid to have a band showing a longer length than the total plasmid? The plasmid was only cut at one restriction site. The plasmid supercoiled so the fragment travelled farther than it should have. The plasmid supercoiled so the fragment did not travel as far as it should have. The plasmid was nicked, losing its ability to coil and move through the gel.

The plasmid was nicked, losing its ability to coil and move through the gel.

____________ proliferate by cutting and pasting the original copy to another part of the genome, while ____________ proliferate by reverse transcribing an mRNA copy of the original and inserting that into another part of the genome. Transposons; short tandem repeats Retroviruses; transposable elements Retrotransposons; transposons Transposons; retrotransposons

Transposons; retrotransposons

True or False: Gene distances in linkage groups can add up to more than 50 map units.

True

True or False: the number of recognition sites for a circular plasmid is equal to the number of resulting fragments.

True

True or false: If you cut a plasmid with two enzymes, A and B, and run the gel, the fragments in the lane A+B cannot be longer than the longest fragments in lane A or lane B.

True

Which of the following statements accurately describe(s) recessive epistasis? Two copies of the hypostatic allele are required to influence pehnotype. Two copies of the epistatic allele are required to influence phenotype. A single copy of the hypostatic allele is sufficient to influence phenotype. A single copy of the epistatic allele is sufficient to influence pehnotype.

Two copies of the epistatic allele are required to influence phenotype.

In the ABO blood type system, which two phenotypes can give rise to all four blood types? Type A and Type O Type B and Type O Type AB and Type O Type A and Type AB Type A and Type B Type AB and Type B

Type A and Type B

Tom and Jane have four children: two girls, Jill and Janet, and two boys, Tim and Todd. Tim has a genetic disorder that gives him polka dotted finger nails, but Todd Jill and Janet do not. All four of the children get married (to people outside their family) and have children. Here are the results: Jill's Children Jack affected with polka dot finger nails Jacob NOT affected with polka dot finger nails John affected with polka dot finger nails Janet's Children Jason NOT affected with polka dot finger nails Justin affected with polka dot finger nails Jessica NOT affected with polka dot finger nails Tim and Todd have NO children affect with polka dot finger nails This genetic disorder is mostly likely: X-linked recessive X-linked dominant Autosomal Recessive Autosomal Dominant Y-linked

X-linked recessive

You have a 5kb plasmid that has one EcoRI restriction site, and a 5kb linear piece of DNA that has one EcoRI restriction site. If you cut both of them with EcoRI which of the following would be true? You would see one band on the gel from the plasmid, and two bands on the gel from the linear piece of DNA. You would see one bands on the gel from the plasmid, and one band on the gel from the linear piece of DNA. You would see two bands on the gel from the plasmid, and one band on the gel from the linear piece of DNA. You would see two bands on the gel from the plasmid, and two bands on the gel from the linear piece of DNA.

You would see one band on the gel from the plasmid, and two bands on the gel from the linear piece of DNA.

Given the parental genotype aBC/abc, which of the following gametes is a possible recombinant? ABC Abc aBc AbC aBC abc

aBc

Complete this sentence: Crossing over occurs...

at the chiasma.

In DNA replication, what is the function and location of the initiator proteins: synthesize RNA on a DNA template to provide an available 3'-OH group to continue with DNA synthesis bind at the origin and begins to unwind the helix work to connect discontinuous parts of DNA such as the nicks created by gyrase and the okazaki fragments bind near the origin to maintain the complementary sequences of DNA from reforming the helical structure

bind at the origin and begins to unwind the helix

The kinetochore attaches the spindle microtubules to the _________________ region of each chromatid or chromosome.

centromere

In parrots, annoying voices (A) are dominant to pleasant ones (a) and brightly colored feathers (B) are dominant to gray ones (b). You testcross a heterozygous annoying, brightly colored parrot and get 2 annoying, gray birds, 27 annoying bright birds, 3 pleasant bright birds, and 25 pleasant gray birds. What is the configuration of the two parental dominant alleles? Both Neither Repulsion Coupling

coupling

In fruit flies, you are mapping three genes in a three point cross. The mutants are hairy body (h), sepia colored eyes (se) and female sterility (g). You cross a heterozygous parent with a homozygous recessive parent and obtain the following results (Wild type allele indicated with a plus sign, +): Type - Number h se g 384 + se + 40 + se g 61 + + g 3 h se + 4 + + + 423 h + g 33 h + + 52 TOTAL 1000 Which of the following correctly shows the order of the genes? h se g g h se h g se g se h

h g se

In humans, knobby knees are dominant over normal knees, and bushy eyebrows are dominant over thin eye brows. Assuming these traits are not linked, what would the phenotype of a child be if the mother is homozygous dominant for both traits, and the father has normal knees, and thin eyebrows?

knobby knees, bushy eyebrows

If two genes are linked, they are... at the same loci on different chromosomes. the same gene. attached by the centromere. on the same chromosome.

on the same chromosome.

What is a "p-value"?

the threshold at which you will reject the null hypothesis

The larger the calculated chi-square value, the more of a chance that you will reject the null hypothesis. (true or false?)

true

If you obtained a 3:1 phenotypic ratio in your F2, your F1 mating was probably between

two heterozygotes

What is crossover? when two alleles switch places on the same chromosome a phenomenon that occurs more often when alleles are closer together on a chromosome when the centromere is switched to the other side of the cell when chromosomes exchange genetic information with each other

when chromosomes exchange genetic information with each other

Which is the correct equation for the chisquare statistic?

x^2 = sum[((observed-expected)^2)/expected]