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

Define nucleosomes , The initial stage of packaging have the binding of t...

The initial stage of packaging have the binding of the chromosomal DNA to histones.  Whole, in chromosomes the ratio of the DNA to histones on a weight basis is around 1:1. There a

Describe the factors of maintenance of implants, What are the special consi...

What are the special considerations required to be taken in maintenance of implants? The procedures for maintenance of patients with implants are similar to those with natural

Phylum annelida are vascular beings, Q. What is signifying when it is said ...

Q. What is signifying when it is said that beings of the phylum Annelida are vascular beings? From which other phyla of the animal kingdom does this feature differentiate them?

Ecological isolation, Ecological isolation is based on the fact that popula...

Ecological isolation is based on the fact that population shows preference to one habitat over the other. This extensive forests become barriers to the dispersal of organims living

What are the different organ of the gastrointestinal system, The different ...

The different organs of the gastrointestinal system  Mouth or buccal cavity - Teeth 32 Permanent and - Tongue  Pharynx  Oesophagus  Stomach  Small Intestine

Explain about hydroxyapatite coating, Hydroxyapatite coating Hydroxyapa...

Hydroxyapatite coating Hydroxyapatite coating has been recommended for clinical use. These implants are superior with respect to the degree and rate of fixation in the bone as

Ontogeny, Ontogeny: This is the study of history of an individual. Ontogen...

Ontogeny: This is the study of history of an individual. Ontogeny is also known as ontogenesis and morphogenesis. Ontogeny describes the origin or the development of an organism -

Epidemiology of plague, Question 1 A patient is admitted to the hospital w...

Question 1 A patient is admitted to the hospital with suspected pneumococcal pneumonia. How would you confirm this initial diagnosis? Answer the following questions a) Which is

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