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

Explain the donnan membrane equilibrium, Explain the Donnan Membrane Equili...

Explain the Donnan Membrane Equilibrium? If one of the solutions in a two-phase membrane equilibrium contains certain charged solute species that are unable to pass through the

Explain the mechanical requirements of implant materials, Mechanical requir...

Mechanical requirements of implant materials Dental implant s must be able to sustain and transfer loads -It should have adequate mechanical strength in order to distribute th

Describes calcium metals, Which of the following terms best describes calci...

Which of the following terms best describes calcium metals? Check all that apply. Molecule, element, matter, and compound

Conditioned reflex , CONDITIONE D REFLEX - Response which is achiev...

CONDITIONE D REFLEX - Response which is achieved by training is conditioned reflex. I. P. Pavlov in 1920 displayed it by experimenting on dog. These are voluntary in

Why does thymine replace uracil in dna, Q. Why does thymine replace uracil ...

Q. Why does thymine replace uracil in DNA? The difference between DNA and RNA is existence of a hydroxyl (-OH) group on 2' carbon of the ribose sugar in the backbone. Removal o

Phylum nematoda (nemathelminthes ), PHYLUM  NEMATODA (= NEMATHELMINTHES ) ...

PHYLUM  NEMATODA (= NEMATHELMINTHES ) Definition and Introduction                                                                             Bilateral  and protostomial

Determine the atomic number of element, A.    In order to determine the ato...

A.    In order to determine the atomic number of an element we need to know the number of protons in an atom. As we know that atom is neutral we can also take the number of electro

Explain epididymitis, Epididymitis  Acute epididymitis in men less than...

Epididymitis  Acute epididymitis in men less than 35 years old is usually caused by C. trachomatis or, less frequently, N. gonorrhoeae. Older men or those who have had urinary

Animal kingdom/pisces, similarity between pisces & mammals about dirhynous ...

similarity between pisces & mammals about dirhynous condition......

Pasteurellosis, Pasteurellosis Haemorrhagic septicaemia (HS) Synonym  ...

Pasteurellosis Haemorrhagic septicaemia (HS) Synonym    :    Gal Ghotu Causative organism B:2                              :    Pasteurella multocida Serotype Haemorrhage sept

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