Textbook Question
If the haploid number for a plant species is 4, how many chromosomes are found in a member of the species that has one of the following characteristics? Explain your reasoning in each case.
Tetraploidy
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Ch. 10 - Eukaryotic Chromosome Abnormalities and Molecular Organization
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172
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Table of contents
- Ch. 1 - The Molecular Basis of Heredity, Variation, and Evolution64
- Ch. 2 - Transmission Genetics144
- Ch. 3 - Cell Division and Chromosome Heredity81
- Ch. 4 - Gene Interaction87
- Ch. 5 - Genetic Linkage and Mapping in Eukaryotes103
- Ch. 6 - Genetic Analysis and Mapping in Bacteria and Bacteriophages73
- Ch. 7 - DNA Structure and Replication71
- Ch. 8 - Molecular Biology of Transcription and RNA Processing79
- Ch. 9 - The Molecular Biology of Translation110
- Ch. 10 - Eukaryotic Chromosome Abnormalities and Molecular Organization100
- Ch. 11 - Gene Mutation, DNA Repair, and Homologous Recombination86
- Ch. 12 - Regulation of Gene Expression in Bacteria and Bacteriophage90
- Ch. 13 - Regulation of Gene Expression in Eukaryotes38
- Ch. 14 - Analysis of Gene Function via Forward Genetics and Reverse Genetics72
- Ch. 15 - Recombinant DNA Technology and Its Applications69
- Ch. 16 - Genomics: Genetics from a Whole-Genome Perspective49
- Ch. 17 - Organelle Inheritance and the Evolution of Organelle Genomes27
- Ch. 18 - Developmental Genetics43
- Ch. 19 - Genetic Analysis of Quantitative Traits66
- Ch. 20 - Population Genetics and Evolution at the Population, Species, and Molecular Levels105
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172Not the one you use?Change textbook
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Sanders 3rd EditionCh. 10 - Eukaryotic Chromosome Abnormalities and Molecular OrganizationProblem 9b
Sanders 3rd EditionCh. 10 - Eukaryotic Chromosome Abnormalities and Molecular OrganizationProblem 9bChapter 10, Problem 9b
Mating between a male donkey (2n = 62) and a female horse (2n = 64) produces sterile mules. Recently, however, a very rare event occurred—a female mule gave birth to an offspring by mating with a horse.
How many chromosomes does the mule–horse offspring carry?
Verified step by step guidance1
Step 1: Understand the chromosome numbers of the parents involved in the mating. A male donkey has 62 chromosomes (2n=62), and a female horse has 64 chromosomes (2n=64). Mules are hybrids formed by combining half the chromosomes from each parent.
Step 2: Determine the chromosome number of the mule. Since mules inherit half of their chromosomes from the donkey and half from the horse, the mule will have (62/2) + (64/2) chromosomes. Use this formula to calculate the mule's chromosome count.
Step 3: Consider the offspring of the mule and horse mating. The mule contributes half of its chromosomes to the offspring, and the horse contributes half of its chromosomes. Use the mule's chromosome count from Step 2 and the horse's chromosome count (64) to calculate the offspring's chromosome number.
Step 4: Add the contributions from the mule and the horse to determine the total chromosome count of the offspring. This involves summing half of the mule's chromosomes and half of the horse's chromosomes.
Step 5: Verify the result conceptually. Since mules are typically sterile due to uneven chromosome pairing, this rare event suggests that the mule's reproductive cells were able to contribute a viable set of chromosomes. Ensure the calculated chromosome number aligns with the expected hybridization pattern.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Chromosome Number in Species
Different species have distinct chromosome numbers, which are crucial for understanding hybridization. In this case, donkeys have 62 chromosomes (2n=62) and horses have 64 chromosomes (2n=64). When these two species mate, their offspring, mules, inherit a mix of chromosomes but typically have an intermediate number, resulting in 63 chromosomes (2n=63), making them sterile due to uneven chromosome pairing during meiosis.
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Hybrid Sterility
Hybrid sterility occurs when the offspring of two different species are unable to reproduce. Mules, the offspring of a male donkey and a female horse, are a classic example of this phenomenon. They possess an odd number of chromosomes (63), which complicates meiosis, preventing the formation of viable gametes. However, rare instances, like the one described, can lead to unexpected reproductive outcomes.
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Chromosome Contribution in Hybrid Offspring
In the case of a mule mating with a horse, the chromosome contribution from each parent is essential to determine the offspring's chromosome number. The mule has 63 chromosomes, while the horse contributes 64. Therefore, the mule-horse offspring would inherit a total of 63 (from the mule) + 64 (from the horse) = 127 chromosomes, which is an unusual scenario but illustrates the complexities of hybrid genetics.
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Related Practice
Textbook Question
If the haploid number for a plant species is 4, how many chromosomes are found in a member of the species that has one of the following characteristics? Explain your reasoning in each case.
Hexaploidy
432
views
Textbook Question
Mating between a male donkey (2n = 62) and a female horse (2n = 64) produces sterile mules. Recently, however, a very rare event occurred—a female mule gave birth to an offspring by mating with a horse.
Determine how many chromosomes are in the mule karyotype, and explain why mules are generally sterile.
703
views
Textbook Question
Mating between a male donkey (2n = 62) and a female horse (2n = 64) produces sterile mules. Recently, however, a very rare event occurred—a female mule gave birth to an offspring by mating with a horse.
Why is it very unlikely that the offspring will have fully horse-like genetic characteristics?
793
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Textbook Question
A researcher interested in studying a human gene on chromosome 21 and another gene on the X chromosome uses FISH probes to locate each gene. The chromosome 21 probe produces green fluorescent color, and the X chromosome probe produces red fluorescent color.
If the subject studied is female, how many green and red spots will be detected? Explain your answer.
489
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Textbook Question
A researcher interested in studying a human gene on chromosome 21 and another gene on the X chromosome uses FISH probes to locate each gene. The chromosome 21 probe produces green fluorescent color, and the X chromosome probe produces red fluorescent color.
If the subject studied is male, how many green and red spots will be detected? Explain your answer.
476
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