Mendelian inheritance
(Redirected from Mendelian ratio)
Mendelian inheritance refers to the patterns of inheritance of traits and genes that were first identified by Gregor Mendel in the 19th century. Through his work on pea plants, Mendel discovered that traits are inherited in predictable ways from parents to offspring. His findings laid the foundation for the field of genetics and are fundamental to understanding how traits are passed down through generations.
Principles of Mendelian Inheritance[edit | edit source]
Mendelian inheritance is based on three key principles:
Law of Segregation[edit | edit source]
The Law of Segregation states that every individual possesses two alleles for each gene, one inherited from each parent. These alleles segregate (separate) during the formation of gametes (sperm and eggs), ensuring that each gamete carries only one allele for each gene. This principle explains why offspring may inherit one of several traits from their parents.
Law of Independent Assortment[edit | edit source]
The Law of Independent Assortment describes how alleles of different genes are distributed independently of one another from parents to offspring. This means the inheritance of an allele for one trait does not influence the inheritance of an allele for another trait, provided the genes are on different chromosomes or far apart on the same chromosome.
Law of Dominance[edit | edit source]
The Law of Dominance states that when two different alleles are present in an organism, one may be dominant and the other recessive. The dominant allele is expressed in the organism's phenotype, while the recessive allele is not, unless the organism is homozygous for the recessive allele.
Extensions and Modifications[edit | edit source]
While Mendel's principles provide a framework for understanding genetic inheritance, later research has shown that inheritance can be more complex due to factors such as codominance, incomplete dominance, and polygenic inheritance. Additionally, linkage occurs when genes are located close together on the same chromosome, leading to an exception to the law of independent assortment.
Genetic Disorders and Mendelian Inheritance[edit | edit source]
Many genetic disorders follow Mendelian inheritance patterns. These can be categorized into autosomal dominant, autosomal recessive, X-linked dominant, and X-linked recessive disorders, depending on the affected gene's location and whether the trait is dominant or recessive.
Impact on Modern Genetics[edit | edit source]
Mendel's work, though initially overlooked, was rediscovered at the turn of the 20th century and has since been recognized as the foundation of classical genetics. His principles have been applied in various fields, including genetic counseling, plant and animal breeding, and molecular biology, to predict the inheritance of traits and understand the genetic basis of diseases.
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
WikiMD's Wellness Encyclopedia |
Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Translate this page: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
தமிழ்,
తెలుగు,
Urdu,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
বাংলা
European
español,
Deutsch,
français,
Greek,
português do Brasil,
polski,
română,
русский,
Nederlands,
norsk,
svenska,
suomi,
Italian
Middle Eastern & African
عربى,
Turkish,
Persian,
Hebrew,
Afrikaans,
isiZulu,
Kiswahili,
Other
Bulgarian,
Hungarian,
Czech,
Swedish,
മലയാളം,
मराठी,
ਪੰਜਾਬੀ,
ગુજરાતી,
Portuguese,
Ukrainian
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD