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

Endosperm with chalazal haustorium, Endosperm with Chalazal Haustorium ...

Endosperm with Chalazal Haustorium In Grevillea robusta, a member of Proteaceae the endosperm is of the free nuclear type. The upper part of endosperm becomes cellular, where

Explain about the toxicity of pyridoxine, Explain about the Toxicity of pyr...

Explain about the Toxicity of pyridoxine? Though toxicity related to pyridoxine intake are rare, but use of high doses of pyridoxine for the treatment of pre-menstrual syndrom

X-ray chest and ecg, X-ray Chest It is helpful in assessing heart size...

X-ray Chest It is helpful in assessing heart size. One should look for presence of pericarditis, pulmonary oedema or pulmonary congestion. ECG One should look for pro

Determine the enzymatic analysis in foods, Enzymatic analysis in foods: app...

Enzymatic analysis in foods: applications in food industry Did you know that the degree of bacterial contamination of foods or freshness of food, particularly, meat etc. can be

Saprophetic mode of nutrition , how parasitic protozoans exibit saprophtic ...

how parasitic protozoans exibit saprophtic mode of nutrition

Determines the concentration of cortisol in the blood plasma, If one determ...

If one determines the concentration of cortisol in the blood plasma to be 10 micrograms/mL and that in a 24 hour period a person excretes 10 mgs of cortisol, calculate the volume o

Briefly explain about semantides, Q. Briefly explain about semantides? ...

Q. Briefly explain about semantides? The information carrying molecules in plants are called semantides, and they have been recognised to be 3 kinds; deoxyribonucleic acid or D

How the wet beriberi developed rapidly, How the Wet beriberi Developed Rapi...

How the Wet beriberi Developed Rapidly? Oedema is the significant feature of wet beriberi. It may develop rapidly and involve not only the legs but also the face, trunk and ser

What compound composes most of the cell membrane, What compound composes mo...

What compound composes most of the cell membrane? How is this compound suited to the function of the membrane? Phospholipid composes most of the cell membrane. The hydrophob

Classify biomaterials and list some examples, Q. Classify biomaterials and ...

Q. Classify biomaterials and list some examples? Biologic classification is based on tissue response and systemic toxicity effects of the implant and is divided into three clas

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