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

What is the vector of malaria, What is the vector of malaria? How different...

What is the vector of malaria? How different is its behavior from the behavior of the vector of dengue fever? The vector of malaria is a mosquito of the genus Anopheles, also k

Determine the symptoms of campylobacteriosis, Determine the Symptoms of Cam...

Determine the Symptoms of Campylobacteriosis Symptoms:  C. jejuni infection causes diarrhoea, which may be watery or sticky and can contain blood and faecal  leukocytes (white

Determine the occurrence of vitamin k, Determine the Occurrence of vitamin ...

Determine the Occurrence of vitamin K Vitamin K is found naturally in plants  and vitamin K2 is synthesized by the bacteria in the intestines in humans. In nature, only two nap

Transport of substances done across the bryophyte tissue, How is the transp...

How is the transport of substances done across the bryophyte tissues? How is this feature related to the general size of these plants? In bryophytes there are no water-conduct

Surgical treatment of infective endocarditis, Cardiac surgical intervention...

Cardiac surgical intervention has an increasingly important role in the treatment of intracardiac complications of endocarditis. Retrospective data suggest that mortality is unacce

State the prevention of flap dehiscence, Prevention of flap dehiscence ...

Prevention of flap dehiscence Flap margin dehiscence (separation) is prevented by approximating the edges of the flap over healthy bone by handling the edges of the flap gently

Zoology , character & classfication of phylum analys

character & classfication of phylum analys

Explain about the macro minerals, Explain about the Macro Minerals? Pre...

Explain about the Macro Minerals? Previously we learnt about the structure, properties, deficiencies/toxicity and recommended dietary intakes of several vitamins. In this unit,

What are the three main types of passive transport, What are the three main...

What are the three main types of passive transport? The three main kinds of passive transport are a)  simple diffusion, b)  osmosis and c)  Facilitated diffusion. C

Determine the molecular function, Please answer the following three questio...

Please answer the following three questions on Sequence Z: Metadata The GO Ontology is a very widely-used resource in the bioinformatics community as a tool to annotate

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