BIOL 3P51 Lecture Notes - Lecture 6: Consanguinity, Zygosity, Dwarfism

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OC1151411

6 Nov 2018

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If homo, then the entuire offspring look the same (like pxp & f1) If hetero, half will be dominant and half will be recessive: 2 gene test cross, take individual showing a recessive trait for both genes (brown body, red eyes, take an unknown (homo or hetero) individual. 29/10/2018: waardenburg syndrome type i, hearing loss, dystopia canthorum, and pigment disturbances of the iris, hair, and skin, white streak in hair, caused by mutation of pax3. Incidence ranges from 1 in 313 to 1 in 90,000 in different populations (avg. = 1 in 3,200 in us: dysfunction impacts many organs that secrete mucus, respiratory tract, pancreas, genitalia (sterile), intestine, sweat glands, clubbed fingers. If they have a ghealthy chil;d what is the probability that this child would not be a cerrir of tay-sachs disease: 100, 2/3, 1/3 of the three healthy children. Only 1 is not a carrier: x-linked inheritance, x chromosome contains many hundreds of important genes.

Related Questions

1. A person is described as a carrier for a particular genetic disease. What does this tell you about their genotype?

2. For any given gene, the principle of independent segregation predicts that each gamete produced as a result of meiosis will contain ____________________

3. A pair of alleles is said to be heterozygous when:

4. In a diploid species, cells can have up to ___ alleles of a particular gene.

5. In a cross between a homozygous dominant parent and a homozygous recessive parent, the number of phenotypic classes observed in the offspring is ______

6. For a person of genotype Xx, the genotype of their gametes may be ______________

7. In a "test cross", an individual of unknown genotype is crossed with a ___ individual to determine the unknown genotype.

8. An albino woman has a child with a phenotypically normal man with no family history of albinism (which is a rare recessive disorder). What percentage of their children are likely to be albino?

9. An individual with the dominant phenotype, but an unknown genotype, is test-crossed, and all of the offspring exhibit the dominant phenotype. The genotype of the unknown individual is ______________

10. If two heterozygous individuals for a recessive disease (carriers) have a child, what is the chance that their child will develop the disease?

11. In a monohybrid cross between two true-breeding parents that both exhibit the dominant phenotype, ___ percent of the offspring will exhibit the recessive phenotype.

12. In a particular type of tomato plant, red fruit is dominant over yellow fruit, and dwarf height is a recessive trait. If two heterozygous plants were crossed, what proportion of the offspring would show the dominant phenotype?

13. In a cross between a BbRr individual and a BBRR one, what do the following represent: BR, Br, bR, br?

14. In humans, the gene that determines whether an embryo develops as a male or a female is carried on _____________

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Please assist with the following. Please no hand-written work, but typed work and thorough explanations please including Punnett Squares. Please Ignore Sex, as these are not sex-linked traits

Dihybrid Testcrosses

In the following crosses, the wild trait is dominant and the brown trait for eye color and ebony trait for body color are both recessive. You will compare the offspring of homozygous wild flies to the offspring of heterozygous wild flies, when each is crossed with a recessive brown-eyed fly with an ebony body.

7. Perform a monohybrid cross between a wild-type female fly and a male fly with brown eyes and ebony body.
Show results for the F₁ offspring. (NOTE: You will use one of these F₁ flies in the next cross.)
ENTER DATA HERE:

PUNNETT SQUARE:

List the genotypes of the flies in this cross:

List the gametes produced by each fly in this cross:

Show the Punnett Square for the above cross.

Question: By examining the offspring, determine whether the wild-type female parent was homozygous or heterozygous for eye color and body color. How did you arrive at this conclusion?

Question: Are the F₁ offspring homozygous or heterozygous for eye color and body color? How did you arrive at this conclusion?

8. Now perform a cross between one wild-type F₁ offspring from the previous cross and a male fly with brown eyes and ebony body.
ENTER DATA HERE:

PUNNETT SQUARE:

List the genotypes of the flies in this cross:

List the gametes produced by each fly in this cross:

Show the Punnett Square for the above cross.

Question: Even though you already knew the genotype of the wild-type fly used in this cross, how can you tell by examining the offspring of this cross whether the wild-type fly in this cross was homozygous or heterozygous for eye color?

Question: What was the phenotypic ratio for the offspring resulting from this testcross?

In need of assistance. Please help answer the following.

1) Pure-breeding yellow guinea pigs crossedwith pure-breeding white guinea pigs produce only cream-coloredoffspring. This pattern indicates incomplete dominance. Rough hairis found to be dominant to smooth hair. Give the F1 and F2genotypic and phenotypic ratios of a cross of a smooth white guineapig with a homozygous rough yellow guinea pig.

2) A breeder of cattle has a herd of white cowsand a roan bull. Hair color in this breed is controlled by anincomplete dominant gene. The two homozygous forms are either redor white, and the heterozygous is roan. Answer the followingquestions please

What color calves are expected and in whatproportion?

Outline a procedure to develop an all-redherd.

3) In horses, black coat color is influenced bythe dominant allele (B), and chestnut coat color is influenced bythe recessive allele (b). Trotting gait is due to a dominant gene(T), pacing gait to the recessive allele (t). If a homozygous blacktrotter is crossed with a chestnut pacer:

What will be the appearance of the F1 and F2generations?

Which phenotype will be the most common?

Which genotype will be the most common?

Which of the potential offspring will be certain tobreed true?

4) In garden peas, one pair of alleles controlsthe height of the plant and a second pair of alleles controlsflower color. The allele for tall (D) is dominant to the allele fordwarf (d), and the allele for purple (P) is dominant for the allelefor white (p). A tall purple crossed with a tall purple produces Â¾tall purple and Â¼ tall white. What is the genotype of the parents?

5) Three alleles control the ABO blood types.I^A and I^B are codominant genes, so thecombination of I^AI^B produces the AB bloodtype. The third allele I^ois recessive to the other twoalleles. Indicate which of these parents could produce the givenchild and submit your response to the instructor.

A X AB produce B child.

A X O produce A child.

A X B produce O child.

A X AB produce O child.

A X AB produce B child.

B X B produce O child.

AB X AB produce A child.

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BIOL 3P51 Lecture Notes - Lecture 6: Consanguinity, Zygosity, Dwarfism

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