1. In Drosophila, the genes for body color (B = black, b = brown), wing size (S = short, s = long) and eye shape (E = oval, e = round) are on different chromosomes. A fly that is heterozygous for all three traits is crossed with a fly that is homozygous recessive for all three traits. Use a branch diagram to answer the following question set. 1a. Determine the gametes produced by each parent. 1b. Perform a trihybrid testcross between the two flies. 1c. What is the phenotypic ratio of the offspring.

1. In Drosophila, the genes for body color (B = black, b = brown), wing size (S = short, s = long) and eye shape (E = oval, e = round) are on different chromosomes. A fly that is heterozygous for all three traits is crossed with a fly that is homozygous recessive for all three traits. Use a branch diagram to answer the following question set. 1a. Determine the gametes produced by each parent. 1b. Perform a trihybrid testcross between the two flies. 1c. What is the phenotypic ratio of the offspring.

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter13: Genes, Chromosomes, And Human Genetics

Section: Chapter Questions

Problem 8TYK: Another gene in Drosophila determines wing length. The dominant wild-type allele of this gene...

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D In fava bean plant the seed color can be coded by two alleles, green (G) which is dominant and purple (g) which is recessive. A gardening hobbyist performed a cross between 2 true-breeding lines P1 and P2 that respectively have green and purple seeds. Answer the following questions in regard to the hobbyist experiment. 1) What are the genotypes of the parental lines A and B? what are the genotypes of the gametes of each parent? 2)What is the phenotype and genotype of the F1 generation of the cross? 3) What are the proportions of the genotypes of the F2 generation? 4)What are the proportions of the phenotypes of the F2 generation?
Calculate the map distances between the three loci.
2.) In fruit flies, L= long wings and 1= short wings. When a long-winged fly is crossed with a short-winged fly, the offspring exhibit a 50:50 phenotypic ratio. What is the genotype of the parent flies? Prove how this is possible. Develop a Punnett square, and then list the genotypes and phenotypes.
1. You are given a female F1 of unknown genotype. You cross the female fly to a homozygous male that has forked bristles and malformed eyes. The offspring of the cross is shown below: (Define symbols for your traits) Phenotype Forked bristles, normal eyes 752 Number Genotype Forked bristles, malformed 56 eyes Malformed eyes, normal bristles Normal eyes, normal bristles 820 64 a. What are the genotypes of the offspring? b. Based on the progeny, what were the genotypes of the F1 parents? What is the distance between for and mal?
6. In Drosophila, Bar eyes (B) is dominant trait located on the X chromosome, apterous wings (ap) are a recessive trait located on chromosome 2, and ebony body color (e) is a recessive trait located on chromosome 3. A homozygous Bar eyed, apterous female is mated to a homozygous ebony male. The F1 flies are crossed. In the F2 generation, at what frequency will Bar eyed, apterous, and ebony males be observed? а. 3/64 b. 1/64 с. О d. 9/64 е. 1/32 f. 3/32
Fruit flies (Drosophila) were mated. Cross #1 - 2 male red eyes (se+), wild wings(ap+) X 4 female red eyes (se+), wild wings(ap+) Cross 2 - 2 male sepia eyes(se-), apterous wings (ap-) X 4 female red eyes(se+), wild wings (ap+) Write out a dihybrid cross and branch diagram for the F2 generatin
1. Take two coins and assume that heads represent the dominantallele (A) and tails represents the recessive allele (a). The genotype for each coin isheterozygous (Aa).2. Assume that each coin represents one parent. When a single coin is flipped, one gameteis formed (through the process of meiosis). If the flipped coin is on heads, then thegamete has the dominant allele (A). When both coins are flipped simultaneously, therewill be two possible gametes that can combine through fertilization to form a zygote. Eachtime you flip both coins, you will record the “genotype” of the offspring.3. Flip the coins 100 times and record your results in the chart below 4. Interpret the data in your tableConclusion:
4. In Drosophila melanogaster, a yellow-bodied (dark coloured) male with vestigial (underformed) wings is crossed to a wildtype female (brown body, red eyes). The F1 generation are all wildtypes. An F1 male and female are crossed and the F2 progeny consists of 16 vestigial-winged males with yellow bodies, 48 yellow males with normal wings, 15 males with vestigial wings and yellow bodies, 49 wildtype males, 31 vestigial winged females with brown bodies and 97 wildtype females. Explain the inheritance pattern of the 2 genes.
Another gene in Drosophila determines wing length. The dominant wild-type allele of this gene produces long wings; a recessive allele produces vestigial (short) wings. A female that is true- breeding for red eyes and long wings is mated with a male that has purple eyes and vestigial wings. F1 females are then crossed with purple-eyed, vestigial-winged males. From this second cross, a total of 600 offspring are obtained with the following combinations of traits: 252 with red eyes and long wings 276 with purple eyes and vestigial wings 42 with red eyes and vestigial wings 30 with purple eyes and long wings Are the genes linked, unlinked, or sex-linked? If they are linked, how many map units separate them on the chromosome?
The F1 flies described in question 1 were mated with brown-eyed flies from a true-breeding line. What phenotypes would you expect the offspring to have? (a) all with red eyes (b) all with brown eyes (c) half with red eyes and half with brown eyes (d) red-eyed females and brown-eyed males (e) brown-eyed females and red-eyed males
A heterozygous individual has a _______ for a trait being studied. a. pair of identical alleles b. pair of nonidentical alleles c. haploid condition, in genetic terms
Fruit flies (Drosophila) were mated. Cross #1 - 2 male red eyes (se+), wild wings(ap+) X 4 female red eyes (se+), wild wings(ap+) Cross #2 - 2 male sepia eyes(se-), apterous wings (ap-) X 4 female red eyes(se+), wild wings (ap+) Cross #3 - 2 male red eyes (se+), wild wings(ap+) X 4 female sepia eyes(se-), apterous wings(ap-) Cross #4 - 2 male sepia eyes(se-), apterous wings (ap-) X 4 female sepia eyes(se-), apterous wings(ap-) Write out a dihybrid cross and branch diagram for the F2 generation.