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

Describe the genetic material of a virus, Q What is the genetic material of...

Q What is the genetic material of a virus? How does that material act in viral reproduction? There is DNA viruses double strand or single strand DNA and RNA viruses double stra

What is green fluorescent protein, Q. What is green fluorescent protein (GF...

Q. What is green fluorescent protein (GFP)? Green fluorescent protein is a protein which is found in a luminescent jellyfish (Aquorea victoria) that lives in cold waters of nor

Which amino acid can form disulfide bonds, a. Which amino acid can form dis...

a. Which amino acid can form disulfide bonds? b. Which level of protein structure do disulfide bonds affect? How? c. Cytoplasmic proteins rarely form disulfide bonds, even if they

Explain the swab method, Explain the Swab Method? Swab method is the ol...

Explain the Swab Method? Swab method is the oldest and widely used method in food and dairy industry and was developed by W.A. Manheimer and T. Ybanez in 1917. A sterile cotton

Protozoa, advantage sand disadvantages of protozoa

advantage sand disadvantages of protozoa

Respiration, what is the meaning of direct and indirect respiration

what is the meaning of direct and indirect respiration

Residual volume - respiration, Residual Volume - Respiration Norma...

Residual Volume - Respiration Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What are the poriferans, Q. What are the poriferans? The phyla Porifera...

Q. What are the poriferans? The phyla Porifera include the simplest creatures of the animal kingdom. Sponges are aquatic sessile beings they are not able to move by themselves

Proteins, Amino Acid - compound with an amino group and a carboxyl group a...

Amino Acid - compound with an amino group and a carboxyl group attached to a central carbon Proteins make up 50% of dry mass of cells in our bodies E.g. of proteins are

What is the spontaneous generation hypothesis, What is the spontaneous gene...

What is the spontaneous generation hypothesis? The spontaneous generation hypothesys, or abiogenesis, asserts that life on earth has come from nonliving material. For instance,

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