During the formation of gametes [eggs and sperm in people and pigeons], chromosomes go through a process called homologous recombination.
Nội dung chính
- In what inheritance a combination of multiple gene pairs is responsible for the production of a particular trait?
- What is multiple inheritance in genetics?
- What is the combination of genes for a trait?
- What is an example of multiple gene inheritance?
First, the cell makes an identical copy of each chromosome. Identical copies are called sister chromatids, and they remain attached to one another for now.
Next, all four copies—two identical copies of two homologous chromosome—line up next to one another, and they swap large sections of DNA. The DNA strands actually break and rejoin. After recombination, the chromosomes still have the same genes arranged in the same order, but the alleles have been rearranged.
Finally, the chromosomes are divvied up so that each gamete gets just one copy of each chromosome. While each gamete ends up with one copy of every gene, they have different combinations of alleles for those genes.
Recombination increases genetic diversity. The location of the chromosome break points is random [or nearly so], and each gamete receives a random copy of each recombined chromosome. All of this jumbling and mixing allows for a nearly infinite number of allele combinations.
Recombination rearranges chromosomes, generating new allele combinations. While just one homologous chromosome pair is shown above, the same process happens for all of them.
Polygenic Trait. As we've gotten better at identifying regions of the human genome that are associated with disease and at analyzing complicated genomic data, we've learned that the genetic component of many of the most important health conditions of our time — cancer, heart disease, diabetes — are due to the effects of multiple genes. Hence, polygenic, or many genes. This has been a fascinating area of study, as scientists have begun to study these conditions and realized that the ways that we have of predicting risks for polygenic traits have tremendous potential for improving human health.
- Entertainment & Pop Culture
- Geography & Travel
- Health & Medicine
- Lifestyles & Social Issues
- Literature
- Philosophy & Religion
- Politics, Law & Government
- Science
- Sports & Recreation
- Technology
- Visual Arts
- World History
- On This Day in History
- Quizzes
- Podcasts
- Dictionary
- Biographies
- Summaries
- Top Questions
- Week In Review
- Infographics
- Demystified
- Lists
- #WTFact
- Companions
- Image Galleries
- Spotlight
- The Forum
- One Good Fact
- Entertainment & Pop Culture
- Geography & Travel
- Health & Medicine
- Lifestyles & Social Issues
- Literature
- Philosophy & Religion
- Politics, Law & Government
- Science
- Sports & Recreation
- Technology
- Visual Arts
- World History
- Britannica Classics
Check out these retro videos from Encyclopedia Britannica’s archives. - Britannica Explains
In these videos, Britannica explains a variety of topics and answers frequently asked questions. - Demystified Videos
In Demystified, Britannica has all the answers to your burning questions. - #WTFact Videos
In #WTFact Britannica shares some of the most bizarre facts we can find. - This Time in History
In these videos, find out what happened this month [or any month!] in history.
- Student Portal
Britannica is the ultimate student resource for key school subjects like history, government, literature, and more. - COVID-19 Portal
While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today. - 100 Women
Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians. - Britannica Beyond
We’ve created a new place where questions are at the center of learning. Go ahead. Ask. We won’t mind. - Saving Earth
Britannica Presents Earth’s To-Do List for the 21st Century. Learn about the major environmental problems facing our planet and what can be done about them! - SpaceNext50
Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!
In what inheritance a combination of multiple gene pairs is responsible for the production of a particular trait?
Polygenic inheritance is also involved in quantitative traits, in which multiple gene loci each contribute in a similar way to the phenotype so that the total number of contributing alleles determines the phenotype.
What is multiple inheritance in genetics?
Multifactorial inheritance is when more than 1 factor causes a trait or health problem, such as a birth defect or chronic illness. Genes can be a factor, but other things that aren't genes can play a part, too. These may include: Nutrition. Lifestyle.
What is the combination of genes for a trait?
Within an individual organism, the specific combination of alleles for a gene is known as the genotype of the organism, and [as mentioned above] the physical trait associated with that genotype is called the phenotype of the organism.
What is an example of multiple gene inheritance?
Polygenic Inheritance: Human skin color is a good example of polygenic [multiple gene] inheritance. Assume that three "dominant" capital letter genes [A, B and C] control dark pigmentation because more melanin is produced.