Skip to main content
Pearson+ LogoPearson+ Logo
Ch. 10 - Eukaryotic Chromosome Abnormalities and Molecular Organization
Sanders - Genetic Analysis: An Integrated Approach 3rd Edition
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172Not the one you use?Change textbook
All textbooksSanders 3rd EditionCh. 10 - Eukaryotic Chromosome Abnormalities and Molecular OrganizationProblem 15a
Chapter 10, Problem 15a

A normal chromosome and its homolog carrying a paracentric inversion are shown here. The dot (·) represents the centromere.
Normal    ABC • DEFGHIJK
Inversion  abc • djihgfe
Diagram the alignment of chromosomes during prophase I.

Verified step by step guidance
1
Understand the problem: A paracentric inversion is a type of chromosomal rearrangement where a segment of a chromosome is inverted but does not include the centromere. Here, the normal chromosome and its homolog with the inversion are given. The task is to diagram their alignment during prophase I of meiosis.
Recall that during prophase I, homologous chromosomes pair up and align to form a synaptonemal complex. This pairing requires homologous regions to align, even if one chromosome has an inversion.
To align the inverted segment with the normal chromosome, the inverted chromosome must form a loop. This is called an inversion loop. The loop allows the inverted sequence to align with the corresponding sequence on the normal chromosome.
Diagram the alignment: Start by drawing the normal chromosome as a straight line with the sequence ABC • DEFGHIJK. Then, draw the homolog with the inversion as a straight line, but include a loop in the region where the inversion occurs (djihgfe). Ensure that the sequences align properly within the loop.
Label the diagram clearly: Mark the centromere (·) on both chromosomes, and indicate the inverted region on the homolog. This will help visualize how the chromosomes align during prophase I.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Homologous Chromosomes

Homologous chromosomes are pairs of chromosomes, one inherited from each parent, that have the same genes at the same loci but may carry different alleles. During prophase I of meiosis, these chromosomes align closely to facilitate genetic recombination, which is crucial for genetic diversity.
Recommended video:
Guided course
07:10
Chromosome Structure

Paracentric Inversion

A paracentric inversion is a chromosomal rearrangement where a segment of a chromosome is inverted but does not include the centromere. This can affect the alignment and pairing of homologous chromosomes during meiosis, potentially leading to complications in gamete formation and genetic variation.
Recommended video:
Guided course
05:15
Inversions

Prophase I of Meiosis

Prophase I is the first stage of meiosis, where homologous chromosomes pair up and exchange genetic material through a process called crossing over. This stage is critical for ensuring proper segregation of chromosomes and increasing genetic diversity in the resulting gametes.
Recommended video:
Guided course
09:06
Meiosis Steps
Related Practice
Textbook Question

Dr. Ara B. Dopsis has an idea he thinks will be a boon to agriculture. He wants to create the 'pomato,' a hybrid between a tomato (Lycopersicon esculentum) that has 12 chromosomes and a potato (Solanum tuberosum) that has 48 chromosomes. Dr. Dopsis is hoping his new pomato will have tuber growth like a potato and the fruit production of a tomato. He joins a haploid gamete from each species to form a hybrid and then induces doubling of chromosome number. Will this hybrid be infertile?

379
views
Textbook Question

Dr. Ara B. Dopsis has an idea he thinks will be a boon to agriculture. He wants to create the 'pomato,' a hybrid between a tomato (Lycopersicon esculentum) that has 12 chromosomes and a potato (Solanum tuberosum) that has 48 chromosomes. Dr. Dopsis is hoping his new pomato will have tuber growth like a potato and the fruit production of a tomato. He joins a haploid gamete from each species to form a hybrid and then induces doubling of chromosome number.

How many chromosomes will the polyploid have after chromosome doubling?

468
views
Textbook Question

Dr. Ara B. Dopsis has an idea he thinks will be a boon to agriculture. He wants to create the 'pomato,' a hybrid between a tomato (Lycopersicon esculentum) that has 12 chromosomes and a potato (Solanum tuberosum) that has 48 chromosomes. Dr. Dopsis is hoping his new pomato will have tuber growth like a potato and the fruit production of a tomato. He joins a haploid gamete from each species to form a hybrid and then induces doubling of chromosome number.

Can Dr. Dopsis be sure the polyploid will have the characteristics he wants? Why or why not?

456
views
Textbook Question

A normal chromosome and its homolog carrying a paracentric inversion are shown here. The dot (·) represents the centromere.

Normal    ABC • DEFGHIJK

Inversion  abc • djihgfe

Assume a crossover takes place in the region between F and G. Identify the gametes that are formed following this crossover, and indicate which, if any, gametes are viable.

720
views
Textbook Question

A normal chromosome and its homolog carrying a paracentric inversion are shown here. The dot (·) represents the centromere.

Normal    ABC • DEFGHIJK

Inversion  abc • djihgfe

Assume a crossover takes place in the region between A and B. Identify the gametes that are formed by this crossover event, and indicate which, if any, gametes are viable.

462
views
Textbook Question

The accompanying chromosome diagram represents a eukaryotic chromosome prepared with Giemsa stain. Indicate the heterochromatic and euchromatic regions of the chromosome, and label the chromosome's centromeric and telomeric regions.

What term best describes the shape of this chromosome?

527
views