Explain the mendel''s laws in genetics, Biology

Assignment Help:

Explain the Mendel's Laws in genetics?

Based on the results of his experiments, Mendel proposed three laws regarding the inheritance of traits: the Law of Segregation, the Law of Independent Assortment, and the Law of Dominance.

The first principle proposed by Mendel, the Law of Segregation, states that "factors" responsible for inheritance of traits remain separate in the offspring, rather than blending . Because traits not apparent in the F1 generation reappeared in the F2 generation, and the F2 generation also had two factors, Mendel concluded that each parent carried two factors that segregate, or separate, during the formation of sperm or egg cells so that they each carry only one factor; therefore the offspring had two factors, the same as the parent.
Since Mendel studied a number of traits, he found that alleles governing different traits, such as position of flowers along the stem; position, shape, and color of the pod; height of the plant; seed texture, seed color, and seed coat color, segregate independently from the alleles that govern another trait. This formed the basis of the second principle, the Law of Independent Assortment. We will see that this law applies only to genes found on different chromosomes.

The third principle, the Law of Dominance, was a result of Mendel's discovery that when two strains were cross-pollinated, one factor in a pair, the dominant factor, may mask the other, so that the dominant trait is always observed in the F1 generation. He called a factor recessive if the trait did not appear until the F2 generation. Some traits were found to exhibit incomplete dominance; that is, heterozygous plants had phenotypes intermediate between the dominant and the recessive. An example is a dominant red flowered plant and recessive white-flowered producing pink-flowered offspring. If dominant traits produce different phenotypes, and both appear in heterozygotes, the traits are called codominant.

539_variations on the mendelian theme.png

There are traits such as skin color in humans that have more than two phenotypes and result from contributions from two or more genes. This condition is called polygenic inheritance. In its simplest form, two genes code for the same trait; an example is kernel color in wheat, where two genes have two alleles, R for red pigment and R' for no pigment at all. The resulting phenotypes exhibit incomplete dominance as with heterozygous single alleles, but there are more shades of red because there are more genes contributing to the trait.


Related Discussions:- Explain the mendel''s laws in genetics

Is there vaccine against tuberculosis, Is there vaccine against tuberculosi...

Is there vaccine against tuberculosis? The vaccine against tuberculosis is known as BCG (bacillus Calmette-Guérin). BCG is not used in some countries where tuberculosis is not

Evolution and scope of dental implantology, The need to replace missing tee...

The need to replace missing teeth has haunted humans for time immemorial. Since antiquity man has attempted to solve the problems associated with failing dentition. The goal of mod

Spoilage of poultry and poultry products, Q. Explain Spoilage of Poultry an...

Q. Explain Spoilage of Poultry and Poultry Products? Poultry meat is the muscle tissue of chicken, ducks, turkey etc. The reference to poultry meat generally is the 'dressed ch

Characteristics of ammonium transport system, Characteristics of Ammonium T...

Characteristics of Ammonium Transport System The following are the characteristics of ammonium transport system: Ammonium transport system is ammonia' repressible

Explain hydrogen transferring coenzymes, Hydrogen Transferring Coenzymes ...

Hydrogen Transferring Coenzymes This group consists  of  three  important coenzymes  all of  which  assist different enzymes  in oxidation-reduction reactions. These are: a

Determine what is the dose to the thyroid, 1. Compute the mean energy per n...

1. Compute the mean energy per nuclear disintegration, A, for 99m TC if 2.0 x 10 9 Bq of this isotope is injected into a patient. Assume that one-half of the administered dose is

Candidiasis, Candidiasis Candidiasis (Moniliasis) is a disease of man, ...

Candidiasis Candidiasis (Moniliasis) is a disease of man, animals and birds and is caused chiefly by Candida albicans. Crop mycosis (thrush) of poultry is caused by C. albicans

Digestive tract, Digestive Tract Extracellular digestion takes place i...

Digestive Tract Extracellular digestion takes place in a tubular cavity that extends throughout the length of the organism. All animals after flatworms have-a tubular alimenta

What is electrocardiogarm, Q. What is Electrocardiogarm? Poor R-wave pr...

Q. What is Electrocardiogarm? Poor R-wave progression, in precordial leads, or q-waves in anterior leads. Intraventricular conduction defects, esqecially LBBB are common. There

What is function of gamaaminobutyric acid, Q. What is function of Gamaamino...

Q. What is function of Gamaaminobutyric acid? GABA is the principal inhibitory transmitter in the brain. The concentration of GABA is up to 1000 times greater than that of oth

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd